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Mammography Follow-up Rates
Methodology
A targeted literature review was designed using relevant breast cancer and
mammography search terms. The search strategy was developed using Medical Subject
Headings (MeSH) related to mammography and breast cancer as well as other relevant
text words identified in a primary literature scan. Results were limited to studies written
in English and conducted in humans in the past ten years. The search was developed to
answer the following evidence questions:
1. What is the evidence surrounding mammography recall rates?
2. To what extent does the diagnostic mammogram accurately detect breast cancer in
patients who are recalled?
3. Of the patients who received a diagnostic mammography/mammary ultrasound,
what is the evidence of improved outcomes?
4. What is the evidence that recall rates differ by patient characteristics?
Profile of Evidence
Brief Review and Discussion of Literature in National Quality Measures
Clearinghouse, National Guideline Clearinghouse, PubMed, and Cochrane
Databases
National Quality Measures Clearinghouse
Our search of the National Quality Measures Clearinghouse (NQMC), using the search
term mammography, returned five relevant documents that were unique to the NQMC.
National Guideline Clearinghouse
Our search of the National Guideline Clearinghouse (NGC), using the search term
mammography, returned six relevant documents that were unique to the NGC.
PubMed
A combination of search strategies including MeSH terms and text words was employed
to identify the full range of literature for each of the key questions. The MeSH terms
included breast neoplasms; mammography; ultrasonography; mammary; mass
screening; time factors; follow-up studies; diagnostic errors; sensitivity and specificity;
quality of life; outcome assessment (health care); prognosis; morbidity; mortality;
healthcare disparities; minority health; risk factors; age factors; comorbidity; poverty;
and social class. Our searches in PubMed returned a total of 71 relevant studies.
1
Cochrane Review Databases
For our review of the Cochrane Review Databases, including the Cochrane Database of
Systematic Reviews, the Health Technology Assessment Database, and the National
Health Service (NHS) Economic Evaluation Database, we used the following MeSH
search terms: breast neoplasms and mammography. We were unable to identify any
studies that were relevant to the key questions and unique to Cochrane (i.e., not
included in the literature found in PubMed).
Magnitude and/or Importance of the Problem
Mammographies and Breast Cancer
The outlook for women with breast cancer has improved in recent years. Due to the
combination of improved treatments and the benefits of mammography screening,
breast cancer mortality has decreased steadily since 1989. Yet breast cancer is the leading
non-skin cancer among U.S. women and the second leading cause of cancer death
among U.S. women. 1 Experience and studies have shown that treatments are most
effective when a cancer is detected early, before it has spread to other tissues. This
suggests that the most effective way to continue reducing mortality from breast cancer is
improved early detection and diagnosis. 2
So far the regular breast cancer detection practice is conducted through semi-annual
mammographies. Generally speaking, detection can consist of two mammographies—
the initial screening and the diagnostic screening. The initial screening mammogram is
an x-ray of the breast used to detect breast changes in patients with no signs or
symptoms of breast cancer. Women are recommended to get a screening mammogram
on an annual or biannual basis. A diagnostic mammogram is an x-ray used to check for
breast cancer after a symptom of breast cancer has been found. The diagnostic
mammogram often follows a screening mammogram if an abnormality has been found
and the patient is recalled. A diagnostic mammogram involves more x-rays and
different angles for the breast than a screening mammogram. 3
Regarding the outcomes of mammographies, several trials have tried to assess whether
mammography reduces mortality and morbidity from breast cancer in women aged 39
and over. In a meta-analysis of seven trials to test mammography’s ability to reduce
breast cancer mortality and morbidity, it was found that mammographies had a
summary relative risk reduction of 0.84 after 14 years of observation (95% confidence,
1 Screening for Breast Cancer, Systematic Evidence Review, Prepared for: Agency for Healthcare Research
and Quality, U.S. Department of Health and Human Services. Portland, OR: Oregon Health Sciences
University, 2002. Accessed May 10, 2009 at
http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat3.chapter.27509
2 Joy J, Penhoet E, Petitti D (Eds.) Saving Women’s Lives: Strategies for Improving Breast Cancer Detection
and Diagnosis. Washington, DC: National Academies Press - Committee on New Approaches to Early
Detection and Diagnosis of Breast Cancer, Institute of Medicine and National Research Council.
3 Screening Mammograms: Questions and Answers. Bethesda, MD: National Cancer Institute, National
Institutes of Health. Accessed May 20, 2009, at
http://www.cancer.gov/cancertopics/factsheet/detection/screening-mammograms
2
.77-.91). 4 When the meta-analysis was limited to only studies that had women over age
50, it found that mammography had a summary relative risk of .81 (95% confidence, .73.89). However, a number of factors may change mammography’s performance. These
factors include age of the woman, breast density, use of hormone replacement therapy,
and family history of breast cancer.
There is no consensus on criteria for recalling a woman from a screening mammography
for a follow-up diagnostic. Although the Mammography Quality Standards Acts of 1992,
1998, and 2004 establish national quality standards of images and image interpretations, 5
mammography practice is still reliant on subjective physician observation and
interpretation. As a result, recall rate variability is common. 6
There are several negative consequences of too many false positive recalls. There is a
small risk of radiation-induced breast cancer. False positives can also result in overdiagnosis and over-treatment of ductal carcinoma in situ, a Stage 0 cancer. 7 Ductal
carcinoma in situ is not regarded as an emergency situation, and almost all diagnosed
women are cured. 8 Younger women, women who have previously had biopsies, women
with a family history of breast cancer, and women on hormone replacement therapy are
more likely to have a false positive. 9
There are also negative consequences of inappropriately low recall rates.
Inappropriately low recall rates may lead to false negatives. A false negative occurs
when a person with breast cancer is not recalled for a diagnostic screening and is not
told that they have breast cancer. As breast cancer treatments are most effective when
used early on in the cancer progression, a false negative and delayed treatment can
result in serious negative health trajectories.
Mammography Cost Considerations
4 Screening for Breast Cancer, Systematic Evidence Review, Prepared for: Agency for Healthcare Research
and Quality, U.S. Department of Health and Human Services. Protland, OR: Oregon Health Sciences
University, 2002. Accessed May 10, 2009 at
http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat3.chapter.27509
5 Report to Congressional Requestors: Mammography: Current Nationwide Capacity is Adequate, but
Access Problems May Exist in Certain Locations. Washington, DC: United States Government
Accountability Office, 2006.
6 Nass S. and Ball J (Eds). Improving Breast Imaging Quality Standards. Washington, DC: National
Academies Press - Committee on Improving Mammography Quality Standards, National Research Council.
2005.
7 Screening for Breast Cancer, Systematic Evidence Review, Prepared for: Agency for Healthcare Research
and Quality, U.S. Department of Health and Human Services. Protland, OR: Oregon Health Sciences
University, 2002. Accessed May 10, 2009 at
http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat3.chapter.27509
8 What is Breast Cancer? Washington, DC: American Cancer Society, 2009. Accessed May 20, 2009 at
http://www.cancer.org/docroot/CRI/content/CRI_2_4_1X_What_is_breast_cancer_5.asp.
9 Screening Mammograms: Questions and Answers. Bethesda, MD: National Cancer Institute, National
Institutes of Health. Accessed May 20, 2009, at
http://www.cancer.gov/cancertopics/factsheet/detection/screening-mammograms
3
The National Health Interview Survey estimates that 33 million women aged 40 and
older received a screening mammogram in 2003. The survey also estimates that 2 million
diagnostic mammograms were performed in 2003. In general, screening mammograms
cost $50 to $150. 10 A study of a New Hampshire mammography registry found that
mean total direct medical costs (imaging and consult) for women who only received a
screening mammogram was $99. For women who also underwent a diagnostic
mammogram, mean total direct costs was $286. 11 Combining national mammography
statistics with estimated individual costs results in rough estimates for national
mammography costs (screening and diagnostic mammograms, consultation and
intervention) of up to $3.9 billion. 12
The same study found that 87 percent of women underwent a screening mammography
only and were responsible for 79 percent of total costs. The 13 percent of women who
received a diagnostic mammogram and other consultation and interventional
procedures (including ultrasounds and biopsies) were responsible for 21 percent of total
costs.
Increases in Imaging Spending
From 2000 through 2006, Medicare Part B spending for imaging services more than
doubled and increased to about $14 billion. 13 While most of the growth in spending can
be attributed to complex procedures like CT scans, MRIs, and nuclear medicine,
spending on simpler procedures—including x-ray mammographies—grew at an
average of 9 percent annually.
Mammographies, along with some other imaging procedures, occur predominantly in
physician offices and independent radiology offices. Medicare Part B imaging spending
that took place in physician offices and diagnostic testing facilities rose from 65 percent
($4.5 billion) of all imaging spending in 2000 to 75 percent ($10.6 billion) in 2006. During
the six year period, physician imaging spending per beneficiary varied substantially
across geographic regions of the country, suggesting that not all utilization was
necessary or appropriate. For example, in 2006, physician spending on imaging per
beneficiary varied from $62 in Vermont to $472 in Florida. 14,15
Nationwide Mammography Capacity
The U.S. General Accounting Office (GAO) found that key capacity elements of
mammographies decreased between 2001 and 2004. More specifically, the numbers of
facilities, machines, radiologic technologists, and interpreting physicians declined; and
Ibid.
Poplack, S. P., Carney, P. A., Weiss, J. E., Titus-Ernstoff, L., Goodrich, M. E., & Tosteson, A. N. A.
Screening mammography: Costs and use of screening-related services. Radiology, 2005;234(1), 79-85.
12 Costs are from mammographies performed in 1996-2000, and the NHIS national estimates are from 2003.
13 Report to Congressional Requesters: Medicare Part B Imaging Services. Washington, D.C.: United States
Government Accountability Office, 2008.
14 Ibid.
15 Readers should keep in mind that costs apply to imaging services overall and should not be regarded as
mammography costs.
10
11
4
facility closures outpaced openings. 16 The GAO also estimated that as the number of
women over 40 increased, there would be an increased demand for mammographies.
But despite the fact that capacity was down and demand projected to go up, the GAO
concluded that nationwide mammography capacity is adequate. Estimates of 2001-2004
capacity found that the number of mammograms performed by U.S. machines was
substantially lower than the number that could be performed. Screening mammograms
accounted for 94 percent of the mammograms provided in 2003, and there was still
excess capacity. The excess capacity for performing screening mammograms in 2003
would have been more than adequate for the estimated 2 million diagnostic
mammograms that were performed that year. However, the GAO cautions that while
there is nationwide excess capacity, some locales may be underserved. Some women
may have to go lengthy distances or have significant wait times for mammographies.
Some of these women may be medically underserved in general.
Overview of Existing Related Measures
Our search of the NQMC yielded five sets of quality measures relevant to
mammography screening for breast cancer. In this section we provide an overview of
our measure including the numerator, denominator, and exclusion criteria used to
calculate the measure. We then provide an overview of the five quality measures
identified through the NQMC.
Outpatient Imaging Efficiency Measure – Mammography Follow-up Rates
The purpose of this measure is to estimate the percentage of patients with
mammography screenings that are followed by a diagnostic mammogram or ultrasound
of the breast in an outpatient or office setting. An abnormally high rate of call-backs
from indeterminate screenings may be an indication of the inability of the reader to
adequately determine when additional imaging is necessary (high false positive rate).
This points to the experience and confidence of the interpreting physician and indicates
both quality and efficiency. Recall rates for follow-up diagnostic mammography studies
greater than 10 to 14 percent are generally felt to be unusually high unless explained by
the morbidity of the underlying population. At the same time, recall rates below a
certain threshold may indicate an underuse of appropriate diagnostic mammography
studies and may be a cause for concern.
•
•
Numerator: The number of patients who had a diagnostic mammography study
or an ultrasound of the breast study following a screening mammography study
(within 45 days).
Denominator: The number of patients who had received a screening
mammography study.
16 Report to Congressional Requestors: Mammography: Current Nationwide Capacity is Adequate, but
Access Problems May Exist in Certain Locations. Washington, DC: United States Government
Accountability Office, 2006.
5
For full technical specifications of the measure please visit the QualityNet website:
http://www.qualitynet.org.
Percentage of patients undergoing screening mammograms whose assessment
category is entered into an internal database that will, at a minimum, allow
analysis of abnormal interpretation (recall) rate.
The American Medical Association, on behalf of the American College of Radiology, the
Physician Consortium for Performance Improvement ® and the National Committee for
Quality Assurance, developed a measure to assess the percentage of patients undergoing
screening mammograms whose assessment category was entered into an internal
database that will allow analysis of abnormal recall rates. Relevant assessment
categories included the Mammography Quality Standards Act (MQSA), Breast Imaging
Reporting and Data System (BI-RADS), or Food and Drug Administration (FDA)
approved equivalent categories. This measure applies to ambulatory care, ancillary
services, hospitals, and physician group practices/clinics. While radiologists surpass
recommendations for mammography services, the recall rate for almost half of
radiologists is higher than recommended. The measure developers assert that collecting
the data elements required to allow for internal calculation of recall rate is a first step in
encouraging quality improvement activities. The measure uses the assessment categories
of several bodies, including the MQSA, BI-RADS, and the FDA, to create an
accountability measure for the abnormal interpretation (recall) rate. 17
•
•
Numerator: Any screening mammograms that receive an MQSA assessment
category of incomplete, probably benign, suspicious or highly suggestive of
malignancy, BI-RADS category of 0, 3, 4, or 5, or FDA-approved equivalent
assessment categories
Denominator: All patients undergoing screening mammograms
Radiology: percentage of final reports for screening mammograms that are
classified “probably benign.”
The American Medical Association, on behalf of the American College of Radiology,
Physician Consortium for Performance Improvement®, and National Committee for
Quality Assurance developed a measure to determine the percentage of final reports for
screening mammograms that are classified “probably benign.” This measure applies to
ambulatory care, ancillary services, hospitals, and physician group practices/clinics. The
mammogram assessment category of “probably benign” is associated with up to 11
percent of screening mammograms and accounts for over 40 to 50 percent of abnormal
screening mammograms; however, the designation of “probably benign,” is reserved for
17 American College of Radiology, Physician Consortium for Performance Improvement®, National
Committee for Quality Assurance. Radiology physician performance measurement set. Chicago, IL:
American Medical Association, National Committee for Quality Assurance 2007. Accessed May 10, 2009 at
http://www.ama-assn.org/ama/no-index/physician-resources/18114.shtml
6
findings that are almost certainly benign according to ACR guidelines. 18 The guidelines
further emphasize that “probably benign is not an indeterminate category for
malignancy, but one that, for mammography, has a less than 2 percent chance of
malignancy (i.e. is almost certainly benign).” The guidelines also state that the diagnosis
comes with a recommendation for short-interval follow-up (typically 6 months) and can
result in economic and emotional consequences. 19 For the purposes of this measure, the
definition of “probably benign” classification includes MQSA assessment category of
”probably benign;” BI-RADS® category 3; or FDA-approved equivalent assessment
category.
•
•
Numerator: Final reports classified as "probably benign"
Denominator: All final reports for screening mammograms
Radiology: percentage of patients undergoing diagnostic mammograms that are
classified as "suspicious" or "highly suggestive of malignancy" with
documentation of direct communication of findings from the diagnostic
mammogram to the patient within 5 business days of exam interpretation.
The American Medical Association, on behalf of the American College of Radiology,
Physician Consortium for Performance Improvement®, and National Committee for
Quality Assurance developed a measure to determine the percentage of patients
undergoing diagnostic mammograms that are classified as ”suspicious” or ”highly
suggestive of malignancy” with documentation of direct communication of findings
from the diagnostic mammogram to the patient within 5 business days of exam
interpretation. This measure applies to ambulatory care, ancillary services, hospitals,
and physician group practices/clinics. Failure to appropriately communicate findings is
a common complaint against radiologists and 28 percent of breast cancer malpractice
claims result from a delay in diagnosis stemming from some type of communication
breakdown. Of those claims, “no direct contact was made for urgent or significant
unexpected findings 71 percent of the time and there was a failure to document attempts
to communicate 90 percent of the time.” In order to prevent delays in patient care, this
measure calls for direct communication within 5 business days. 20
18 American College of Radiology Appropriateness Criteria: Nonpalpable breast masses. Reston, VA:
American College of Radiology 2005. Accessed May 10, 2009 at
http://www.acr.org/SecondaryMainMenuCategories/quality_safety/app_criteria/pdf/ExpertPanelonWo
mensImagingBreastWorkGroup.aspx
19 American College of Radiology, Physician Consortium for Performance Improvement®, National
Committee for Quality Assurance. Radiology physician performance measurement set. Chicago, IL:
American Medical Association, National Committee for Quality Assurance 2007. Accessed May 10, 2009 at
http://www.ama-assn.org/ama/no-index/physician-resources/18114.shtml
20 American College of Radiology, Physician Consortium for Performance Improvement®, National
Committee for Quality Assurance. Radiology physician performance measurement set. Chicago, IL:
American Medical Association, National Committee for Quality Assurance 2007. Accessed May 10, 2009 at
http://www.ama-assn.org/ama/no-index/physician-resources/18114.shtml
7
•
•
Numerator: Patients with documentation of direct communication of findings
from the diagnostic mammogram to the patient within 5 business days of exam
interpretation
Denominator: All patients undergoing diagnostic mammograms that are
classified as “suspicious” or ”highly suggestive of malignancy”
Breast cancer screening: percentage of women 40-69 years of age who had one or
more mammograms during the measurement year or the year prior to the
measurement year.
As a part of the Healthcare Effectiveness Data and Information Set (HEDIS ®) 2008, the
National Committee for Quality Assurance (NCQA) developed a measure to calculate
the percentage of women 40-69 years of age who had one or more mammograms during
the measurement year or the year prior to the measurement year. This measure applies
to managed care plans and is used for accreditation; decision-making by businesses
about health-plan purchasing; decision-making by consumers about health plan and
provider choice; external oversight of the Medicaid program; external oversight of the
Medicare program; external oversight of State government programs; internal quality
improvement; and national reporting purposes. This measure excludes women with
biopsies, breast ultrasounds or other diagnostic mammograms from the numerator and
women who have had a bilateral mastectomy from the denominator. 21
•
•
Numerator: Women with one or more screening mammograms during the
measurement year or the year prior to the measurement year.
Denominator: Women 42 through 69 years of age as of December 31 of the
measurement year
Diagnosis of breast disease: percentage of class 4 or 5 abnormal mammograms
that are followed with biopsy within 7 to 10 days.
The Institute for Clinical Systems Improvement developed a measure to assess the
percentage of class 4 or 5 abnormal mammograms that are followed with biopsy within
7 to 10 days in women 74 years or younger. This measure applies to physician group
practices and clinics. The rationale for this measure is to reduce the length of time
between first knowledge of a breast abnormality and diagnostic resolution. 22
•
•
Numerator: Total number of patients within 7 to 10 days between the first
documentation of a mammogram abnormality and a complete biopsy for all
records reviewed
Denominator: Total number of patients with an abnormal mammogram
undergoing biopsy
21 National Committee for Quality Assurance (NCQA). HEDIS 2008: Healthcare Effectiveness Data &
Information Set. Vol. 2, Technical Specifications. Washington (DC): National Committee for Quality
Assurance (NCQA); 2007 Jul.
22 Institute for Clinical Systems Improvement (ICSI). Diagnosis of breast disease. Bloomington (MN):
Institute for Clinical Systems Improvement (ICSI); 2008 Jan.
8
Overview of Existing Guidelines
In addition to established quality measures for mammography for breast cancer
screening, our search identified six practice guidelines and appropriateness criterion
related to recall rates in screening mammography in NGC.
American College of Radiology Guidelines (2008) and Appropriateness Criteria (2005)
The 2008 American College of Radiology Practice Guideline for the Performance of
Screening and Diagnostic Mammography advises that all mammographies must be
performed in accordance with the Mammography Quality Standards Act (MSQA) final
rule as published by the FDA. 23 The guideline further explains the difference between a
screening and a diagnostic mammogram, specifying that a screening mammogram is
performed to detect unsuspected breast cancer in asymptomatic women while
diagnostic mammography is performed to evaluate patients who have signs and/or
symptoms of breast disease, imaging findings of concern, or prior imaging findings
requiring specific follow-up. 24 Patients eligible for screening mammography include
asymptomatic women aged 40 years or older with or without breast implants who are
either self-referred or self-requested. The guidelines specify that diagnostic
mammography is appropriate for patients with the following characteristics: 25
•
•
•
•
•
a specific focus of clinical concern including, but not limited to, mass, induration,
axillary lymphadenopathy, some types of nipple discharge, skin changes, or
persistent focal areas of pain or tenderness;
a possible radiographic abnormality detected on screening mammography.
recommended for short-interval follow-up (e.g., less than 1 year) for probably
benign radiographic findings as defined by the ACR Breast Imaging Reporting
and Data System (BI-RADS ®);
whose examination requires direct involvement of the radiologist for special
views, physical breast examination, or consultation; and
who have been treated for breast cancer in the past.
Further, for patients arriving for a screening mammogram with an indication of a
clinical problem, the facility should have a mechanism in place to convert these patients
to diagnostic mammography. 26
The ACR guidelines provide an overview of the BI-RADS assessment categories for
mammography including the recommended action (Table 1). Further imaging is
23 ACR practice guideline for the performance of screening and diagnostic mammography. Reston, VA:
American College of Radiology 2008. Accessed May 10, 2009 at
http://www.acr.org/SecondaryMainMenuCategories/quality_safety/guidelines/breast/Screening_Diagn
ostic.aspx
24 Ibid.
25 Ibid.
26 Ibid.
9
indicated for categories 0, 3, 4, and 5. 27
Table 1
ACR Overview of BI-RADS Assessment Categories
Incomplete
BI-RADS ®
Assessment
Category
0
Complete
Complete
Complete
1
2
3
Complete
4
Complete
5
Complete
6
Mammographic
Assessment
Description
Need additional imaging evaluation and/or prior
mammograms for comparison
Negative
Benign findings
Probably benign finding – initial short-interval
follow-up suggested
Suspicious abnormality – biopsy should be
considered
Highly suggestive of malignancy – appropriate action
should be taken
Known biopsy – proven malignancy – appropriate
action should be taken.
The guideline also provides information on the time-frame for communication of
screening and diagnostic mammography results to patients. Regardless of the result, a
facility must provide a written report of the mammography examination to the patient’s
healthcare provider within 30 days of the exam. In cases of BI-RADS ® category 4 and 5
results, the facility must communicate results to the healthcare provider and patient
within 3 and 5 working days, respectively. 28
In a related document, the ACR identifies its appropriateness criteria for screening for
nonpalpable masses including mammography and mammary ultrasound. 29 The criteria
differentiate variations of nonpalpable masses into seven categories. Below, we
summarize the appropriateness rating of mammography and mammary ultrasound use
by nonpalpable mass variation (Table 2). 30 Note that the appropriateness score ranges
from 1 (least appropriate) to 9 (most appropriate).
Table 2
Ibid.
Ibid.
29 D'Orsi CJ, Bassett LW, Berg WA, Bohm-Velez M, Evans WP III, Farria DM, Lee C, Mendelson EB,
Goldstein S. Nonpalpable breast masses. Reston, VA: American College of Radiology 2005. Accessed May
10, 2009 at
http://www.ngc.org/summary/summary.aspx?doc_id=8323&nbr=004655&string=ACR+AND+Mammogr
aphy
30 D'Orsi CJ, Bassett LW, Berg WA, Bohm-Velez M, Evans WP III, Farria DM, Lee C, Mendelson EB,
Goldstein S. Nonpalpable breast masses. Reston, VA: American College of Radiology 2005. Accessed May
10, 2009 at
http://www.ngc.org/summary/summary.aspx?doc_id=8323&nbr=004655&string=ACR+AND+Mammogr
aphy
27
28
10
ACR Appropriateness Rating for Mammography and
Mammary Ultrasound by Nonpalpable Mass Variation
Variant
Focal asymmetries
Round, oval or lobular mass
with circumscribed, partially
obscured margin on baseline
screening mammogram
Spiculated and/or ill-defined
masses
Circumscribed (> 75%),
partially obscured mass with
coarse, dystrophic and/or
"popcorn" calcification
Circumscribed/partially
obscured mass with
pleomorphic/amorphous
and/or heterogeneous
calcifications
Irregular spiculated/indistinct
mass with coarse/dystrophic
and/or "popcorn" calcification
Irregular spiculated/indistinct
mass with
pleomorphic/amorphous
and/or heterogeneous
calcification
X-ray, breast
diagnostic
mammography
(out of a possible
score of 9)
9 (with
supplemental
views)
Ultrasound,
breast (out of a
possible score
of 9)
Shortinterval
Follow-up
8
4
9
9 (diagnostic)
3
9
5 (diagnostic)
1
4
2
1
9
7
1
8
8
1
9
5
1
American College of Obstetricians and Gynecologists (2003)
In a 2003 guideline released by the American College of Obstetricians and Gynecologists
(ACOG), recommendations for the use of breast cancer screening techniques are
provided, including:
•
•
•
•
•
Mammography screening
Clinical breast examination and breast self-examination
Ultrasonography
Biopsy
Referral to a professional experienced in the diagnosis of cancer
11
•
Genetic counseling and testing
In the development of these guidelines, ACOG considered breast cancer survival and
mortality rates, risks and benefits of mammography screening, sensitivity and specificity
of clinical breast examination, and risk factors for breast cancer. While the guidelines
provide no recommendations directly relevant to the measure for recall rates for
mammography screening, the ACOG does recommend women aged 40-49 years should
have screening mammography every 1 to 2 years, and women aged 50 years and older
should have annual screening mammography. 31
American College of Physicians (2007)
The American College of Physicians (ACP) released a clinical practice guideline in 2007
for screening mammography for women 40 to 49 years of age including four specific
recommendations: 32
1. In women 40 to 49 years of age, clinicians should periodically perform
individualized assessment of risk for breast cancer to help guide decisions about
screening mammography
2. Clinicians should inform women 40 to 49 years of age about the potential
benefits and harms of screening mammography
3. For women 40-49 years of age, clinicians should base screening mammography
decisions on benefits and harms of screening, as well as on a woman’s
preferences and breast cancer risk profile
4. Further research on the net benefits and harms of breast cancer screening
modalities for women 40 to 49 years of age is recommended
Recommendations 1 and 2 are of greatest relevance to the mammography follow-up rate
measure. In reference to the rationale for recommendation (1), the ACP notes that the 5year breast cancer risk can vary from 0.4 percent in women age 40 years with no risk
factors to 6.0 percent in women age 49 years with several risk factors. These risk factors
include older age, family history of breast cancer, older age at time of first birth, younger
age and menarche, and history of breast biopsy. 33 The rationale for recommendation (2)
states that the most important benefit of screening mammography every one to two
years for women 40 to 49 years of age is a potential decrease in breast cancer mortality.
The guidelines cite a recent meta-analysis that concluded relative reduction in the breast
cancer mortality rate is 15 percent after 14 years of follow-up. 34 False-positives were
cited as the greatest potential harm.
31 American College of Obstetricians and Gynecologists (ACOG). Breast cancer screening. Washington, DC:
American College of Obstetricians and Gynecologists 2003. Accessed May 10, 2009 at
http://www.ngc.org/summary/summary.aspx?doc_id=3990&nbr=003129&string=mammography+AND+
2003
32 Qaseem A, Snow V, Sherif K, et al. Screening mammography for women 40 to 49 years of age: A clinical
practice guideline from the American College of Physicians. Annals of Internal Medicine 2007;146:511-515.
33 Ibid.
34 Humphrey LL, Helfand M, Chan BK, Woolf SH. Breast cancer screening: a summary of the evidence for
the U.S. Preventive Services Task Force. Annals of Internal Medicine 2002;137:347-60.
12
American Cancer Society (2007)
In 2002, the American Cancer Society (ACS) convened an expert panel to review the
existing guidelines and develop recommendations regarding: 35
1.
2.
3.
4.
5.
Mammography
Physical examination
Screening of older women
Screening of high-risk women
Screening with new technologies
Of particular relevance to the mammography follow-up rate measure are
recommendations (1), (3), and (4). Specific to mammography, the ACS recommends: 36
•
•
•
Women with average risk of breast cancer should have an opportunity to become
informed about the benefits, limitations, and potential harms associated with
regular screening.
Screening detections in older women should be individualized by considering
the potential benefits and risks of mammography in the context of current health
status and estimated life expectancy. As long as a woman is in reasonably good
health and would be a candidate for treatment, she should continue to be
screened with mammography.
Women at increased risk of breast cancer might benefit from additional screening
strategies beyond those offered to women of average risk, such as earlier
initiation of screening, shorter screening intervals, or the addition of screening
modalities other than mammography and physical examination, such as
ultrasound or magnetic resonance imaging. However, the evidence currently
available is insufficient to justify recommendations for any of these screening
approaches.
The ACS cites a number of studies demonstrating the percent mortality reduction
achieved through screening mammography. In all trials combined, the average percent
breast cancer mortality reduction was 24 percent with 95 percent of studies falling
within 18-30 percent mortality reduction for women at average risk. 37
In older women, there is limited data and the guidelines cite only one randomized
control trial including women over the age of 69. Among women 65 and older,
mammography sensitivity was found to be 81 percent, significantly more sensitive than
for women aged 50-64, 40-49, or less than 40 years of age. 38 Additional factors to
consider in older populations include hormone replacement therapy, breast density, life
Smith RA, Saslow D, Sawyer KA, et al. American Cancer Society guidelines for breast cancer screening:
update 2003. CA: A cancer journal for clinicians 2003;53:141-169.
36 Ibid.
37 Ibid.
38 Rosenberg RD, Yankaskas BC, Abraham LA, et al. Performance benchmarks for screening mammography.
Radiology 2006;241(1):55-66.
35
13
expectancy, and comorbidities (e.g., diabetes, renal failure, stroke, liver disease, and
previous cancer). 39
A number of risk factors have been identified over the years for breast cancer. Of these
risk factors, age and sex are the most important. For the purposes of this guideline,
increased risk factors for breast cancer include: 40
• Two or more relatives with breast or ovarian cancer;
• Breast cancer occurring before age 50 in a relative;
• Relatives with both breast and ovarian cancer; breast and ovarian cancer; or two
independent breast cancers;
• Male relatives with breast cancer;
• A family history of breast or ovarian cancer and Ashkenazi Jewish heritage
The guideline concludes that there is a general need for further research to truly validate
the recommendations for screening of women at increased risk for breast cancer.
Institute for Clinical Systems Improvement (2008)
A final set of guidelines from the Institute for Clinical Systems Improvement released in
2008 provides a recommendation in the instance of an abnormal screening or diagnostic
mammogram, specifically: an abnormal finding on routine mammography should be
evaluated under the direction of a radiologist in order that a full characterization of the
lesion be provided back to the primary care physician ordering the original study. 41
The guidelines further specify individuals at increased risk for breast cancer as
those who have: 42
• Previous breast biopsy demonstrating ductal hyperplasia with atypia
• Family history of breast or ovarian cancer in the patient's mother, sister or
daughter under age 50, or breast cancer in male family member
• Past, personal history of breast cancer
• A breast cancer gene
• Previous radiation to the chest (i.e., Hodgkin's Disease)
Evidence Questions
Key Question 1: What is the evidence surrounding mammography recall rate?
Our search returned 11 articles that provided information regarding the evidence
surrounding mammography recall rates.
39 Smith RA, Saslow D, Sawyer KA, et al. American Cancer Society guidelines for breast cancer screening:
update 2003. CA: A cancer journal for clinicians 2003;53:141-169.
40 Ibid.
41 Institute for Clinical Systems Improvement (ICSI). Diagnosis of breast disease. Bloomington, MN: Institute
for Clinical Systems Improvement 2008. Accessed May 11, 2009 at
http://www.icsi.org/breast_disease_diagnosis/diagnosis_of_breast_disease_2.html
42 Ibid.
14
Recall Rates
One retrospective study evaluated a range of radiologist performance outcomes,
including positive predictive value, recall rate, cancer detection rate, mean cancer size,
and cancer stage. As radiologists were evaluated, they were placed in performance
ranges. The middle 50 percent of radiologists had an average recall rate of 9.8 percent on
average, and rates ranged from 6.4 to 13.3 percent (n=2,580,151). 43 In another study,
recall rates of 10 percent for first mammograms (n=1,872,687) and 6.7 percent for
subsequent (n=171,104) mammograms are recommended targets on the basis of their
AW/ACD (additional work-ups per additional cancer detected). 44 Alternatively,
another article (n=215,665) found that practices with recall rates between 4.9 percent and
5.5 percent achieve the best trade-off of sensitivity and positive predictive value. 45
Similarly, in a prospective observational study of a Swiss mammography screening pilot
program, the recall rate for the screening mammogram was 4.6 percent, and the recall
rate for the diagnostic mammogram was 2.3 percent. 46 Lastly, a study that evaluated the
false positive recall rate of a Norwegian program that administered biannual screening
mammographies found that the first screening mammography of the year had a false
positive recall rate of 4.6 percent, and second screening mammography of the year had a
false positive recall rate of 2.6 percent. 47 While these last three studies report recall rates
substantially lower than the first few studies, it should be noted that these studies are
performed in foreign countries and may be comparable to studies conducted in the
United States.
Recall Waiting Periods
Three articles addressed recall waiting periods. The recall waiting period is the number
of days between the screening mammography and the diagnostic mammography. One
pilot study (n=1,137) found process change can significantly decrease the waiting time
to diagnosis after an abnormal breast screen. It found that facilitating the referral process
had the greatest impact in reducing the median time to diagnosis for women without a
biopsy. With facilitated referrals, median time to diagnosis was reduced from 23 days to
7 days. 48 Another article (n=10,314) evaluated the timeliness of diagnosis after an
abnormal screening in the Screening Mammography Program of British Columbia
(SMPBC) and found the median time from abnormal screening to diagnosis was 3.4
weeks with regional variation of 2 to 4.7 weeks, and 10 percent of women had to wait 8.7
weeks or more. For women proceeding to biopsy, the median diagnostic interval was 7.1
43 Rosenberg RD, Yankaskas BC, Abraham LA, et al. Performance benchmarks for screening mammography.
Radiology 2006;241(1):55-66.
44 Schell MJ, Yankaskas BC, Ballard-Barbash R, et al. Evidence-based target recall rates for screening
mammography. Radiology 2007;243(3):681-9.
45 Yankaskas BC, Taplin SH, Ichikawa L, et al. Association between mammography timing and measures of
screening performance in the United States. Radiology 2005;234(2):363-73.
46 Bulliard JL, De Landtsheer JP, Levi F. Results from the Swiss mammography screening pilot programme.
European Journal of Cancer 2003;39(12):1761-9.
47 Hofvind S, Vacek PM, Skelly J, Weaver DL, Geller BM. Comparing screening mammography for early
breast cancer detection in Vermont and Norway. Journal of the National Cancer Institute 2008;100(15):1082-91.
48 Olivotto IA, Borugian MJ, Kan L, et al. Improving the time to diagnosis after an abnormal screening
mammogram. Canadian Journal of Public Health 2001;92(5):366-71.
15
weeks with regional variation of 4.6 to 9.3 weeks. 49
One study (n=8,698) found that immediate interpretation of screening mammograms
resulted in statistically significant increases in recalls and additional clinical work-ups of
perceived abnormalities. 50 Immediate interpretations occur when the radiologist
evaluates the results immediately after the mammogram. The results are communicated
with the patient and any additional diagnostic imaging is also performed in the initial
visit. Recall waiting periods for immediate interpretations are therefore zero days. Batch
interpretations are performed after the patient has left the care setting, and patients are
notified of results at a later time. Recall waiting periods for batch interpretations are
therefore at least 1 day. The group of immediate interpretation mammograms had a
recall rate of 18 percent, while the batch interpretation group had a recall rate of 14
percent.
International Comparisons of Mammography Recall Rates
A retrospective observational study compared mammography cases in Vermont and
Norway (n=239,480). There was a 9.8 percent recall rate for screening mammographies
in Vermont and a 2.7 percent recall rate in Norway. Cancer detection rate was 2.77 per
1000 screening mammographies in Vermont and 2.57 in Norway. Prognostic
characteristics were similar between locations. 51 Another retrospective observational
study compared 5.5 million screening mammography cases between the U.S. and the
United Kingdom. It found that recall rates were approximately twice as high in the US
than in the UK. The study found recall rates of 14.4 percent in the Breast Cancer
Surveillance Consortium (U.S.), 12.5 percent in the National Breast and Cervical Cancer
Early Detection Program (U.S.), and 7.6 percent in National Health Service Breast
Screening Programme (U.K.). 52
Key Question 2: To what extent does the diagnostic mammogram accurately
detect breast cancer in patients that are recalled?
Our search returned 28 articles that provided information regarding the cancer detection
rate using mammography, with seven of those specifically about cancer detection rates
of the diagnostic mammogram.
Breast Cancer Detection Rates
Findings in two studies surrounding breast cancer detection rates were contradictory.
49 Olivotto IA, Kan L, King S. Waiting for a diagnosis after an abnormal screening mammogram. SMPBC
diagnostic process workgroup. Screening Mammography Program of British Columbia. Canadian Journal of
Public Health 2000;91(2):113-7.
50 Ghate SV, Soo MS, Baker JA, Walsh R, Gimenez EI, Rosen EL. Comparison of recall and cancer detection
rates for immediate versus batch interpretation of screening mammograms. Radiology 2005;235(1):31-5..
51 Hofvind S, Geller B, Vacek PM, Thoresen S, Skaane P. Using the European guidelines to evaluate the
Norwegian Breast Cancer Screening Program. European Journal of Epidemiology 2007;22(7):447-55.
52 Smith-Bindman R, Chu PW, Miglioretti DL, et al. Comparison of screening mammography in the United
States and the United kingdom. Journal of the American Medical Association 2003;290(16):2129-37.
16
One study (n=556) reported that the diagnostic mammogram’s accuracy is very high
and had a sensitivity of 86.8 percent, a specificity of 98.6 percent, with a positive
predictive value of 68.8 percent and a negative predictive value of 99.5 percent. 53
Another study (n=332,926 diagnostic mammographies) had an abnormal interpretation
rate of 8 percent, a positive predictive value for recommended biopsy of 31.4 percent,
and a 39.5 percent cancer diagnosis rate. 54 Due to differences in the methodological
approach, it is not possible to make comparisons between these two studies as to why
the rates are so different.
Another retrospective study (n=495) examined how cancer detection was influenced by
screening mammography recall rate. It found that increasing the recall rate to 2 percent
would increase the detection rate from 4.2 per 1,000 to 4.52 per 1,000. At recall rates of 3
percent and 4 percent the detection would increase to 4.58 per 1000 and 4.63 per 1000,
respectively. Breast cancer can be detected earlier by lowering the threshold for recall,
especially for recall rates of one to four percent. With further recall rate increases, cancer
detection levels off with a disproportionate increase of false-positive rates. 55
Screening vs. Diagnostic Mammography Cancer Detection Rates
One study (n=1,171,792) found that the cancer detection yield for short-interval followup based on first screening examination is lower than that with diagnostic work-up
prior to short-interval follow-up recommendation. 56 Another study (n=7,506) found that
detection rates were very different for screening and diagnostic mammographies: the
screening cancer detection rate was 6.1 per thousand cases, while the diagnostic
detection rate was much higher, at 86.4 per thousand. 57 A third study found that
diagnostic mammographies had abnormal findings 14.4 percent of the time and
screenings had abnormal findings 5.2 percent of the time; and cancer detection was 55
per 1000 for diagnostics and 5 per 1000 for screenings (n=46,857). 58
Another study found that women who undergo a screening mammography followed by
a diagnostic mammography and sonography on the same day have a higher probability
of undergoing a biopsy (n=584,470 women). They also had a higher probability of
having that biopsy indicate cancer. About 20.1 percent of those who have the diagnostic
mammography and sonography on the same day as the screening mammography
53 Sidhartha, Thapa B, Singh Y, Sayami P, Khanal U. Mammographic diagnosis of breast carcinoma: an
institutional experience. Journal of Nepal Medical Association 2008;47(170):62-5.
54 Sickles EA, Miglioretti DL, Ballard-Barbash R, et al. Performance benchmarks for diagnostic
mammography. Radiology 2005;235(3):775-90.
55 Otten JD, Karssemeijer N, Hendriks JH, et al. Effect of recall rate on earlier screen detection of breast
cancers based on the Dutch performance indicators. Journal of the National Cancer Institute 2005;97(10):74854.
56 Kerlikowske K, Smith-Bindman R, Abraham LA, et al. Breast cancer yield for screening mammographic
examinations with recommendation for short-interval follow-up. Radiology 2005;234(3):684-92.
57 Tuncbilek I, Ozdemir A, Gultekin S, Ogur T, Erman R, Yuce C. Clinical outcome assessment in
mammography: an audit of 7,506 screening and diagnostic mammography examinations. Diagnostic and
Interventioanl Radiology 2007;13(4):183-7.
58 Dee KE, Sickles EA. Medical audit of diagnostic mammography examinations: comparison with screening
outcomes obtained concurrently. American Journal of Roentgenology 2001;176(3):729-33.
17
undergo a biopsy, compared to 18.9 percent of those who had the screening and
diagnostic mammographies on different days. About 37 percent of biopsies performed
after same-day screening and diagnostic mammographies turned out to have cancer. In
comparison, biopsies performed after sonographies in the absence of a diagnostic
mammography had a lower yield of breast cancer detection—12 to 17 percent. 59
Cancer Detection Variation by Technology Differences
Another study looked at the use of ultrasounds when breasts were too dense for
mammographies. The incremental cancer detection rate was 0.40 percent. About 65
percent of ultrasound-only detected cancers were detected at an earlier, more favorable
stage than mammography-only detected cancers (35.5 percent). 60
International Comparisons of Cancer Detection Rates
Looking at international studies can show how cancer detection varies by country. In
one observational study of Swiss mammography screening pilot program, the recall rate
for the initial mammography was 4.6 percent. About 84.7 percent of these women did
not have breast cancer. There was a 2.3 percent recall rate in the subsequent round and
75.6 percent of recalled women did not have breast cancer. 61
Key Question 3: Of the patients who received a diagnostic mammography/mammary
ultrasound, what is the evidence of improved outcomes?
Our search yielded 8 studies that provided information regarding the relationship
between mammography and evidence of improved outcomes. Of these studies, there
were two modeling/simulation studies, three prospective studies, and two retrospective
studies. Some of the studies address improved outcomes in relation to screening
mammographies rather than diagnostic mammographies.
Mammographies and Mortality Rates
Most of the studies used breast cancer mortality as the main performance outcome of
screening. Many (but not all) studies found that screening was associated with reduced
breast cancer mortality. In one modeling study (n = 2 million), posterior mean reduction
in breast cancer mortality (BCM) due to screening mammography was 10.6 percent
(with an error of margin of 5.7 percent). Despite this uncertainty, the study concluded
with high probability that screening contributed to the reduction in BCM observed in
59 Carney PA, Abraham LA, Miglioretti DL, et al. Factors associated with imaging and procedural events
used to detect breast cancer after screening mammography. American Journal of Roentgenology
2007;188(2):385-92.
60 Corsetti V, Houssami N, Ferrari A, et al. Breast screening with ultrasound in women with mammographynegative dense breasts: evidence on incremental cancer detection and false positives, and associated cost.
European Journal of Cancer 2008;44(4):539-44.
61 Bulliard JL, De Landtsheer JP, Levi F. Results from the Swiss mammography screening pilot programme.
European Journal of Cancer 2003;39(12):1761-9.
18
the US between 1990-2000. 62 Another simulation study found that breast screening
mammographies from the age of 50-69 years reduced the overall number of deaths from
breast cancer by 5.7 to 8 percent. 63 One prospective observational study also found that
mortality risk was reduced for those who received screening mammographies, and
mortality risk was even reduced for those who received mammographies and had a
more severe, late-stage form of cancer. The study (n = 36,000 women) found that
screening had a beneficial effect even in women whose cancer had already spread into
the axillary lymph nodes. 64 Another prospective observational research paper found that
5-year overall observed survival rates were 94 percent for the 372 patients with cancers
that were detected by mammography alone. Survival rates were 87 percent for the 677
whose cancers were detectable by palpation. 65
One retrospective observational study used both mortality and stage of diagnosis as the
outcome measure. It found that women who undergo regular screening
mammographies are about half as likely as women who do not to be diagnosed at a late
stage (n = 247). 66
Another study, a meta-analysis of seven randomized control trials, found that
mammographies did not reduce risk of breast cancer mortality (It is unclear whether the
studies were in reference to the screening mammography, diagnostic mammography, or
both). The highest-quality trials failed to show a significant reduction in breast cancer
mortality with a relative risk of 0.97. With all data considered, the meta-analysis found
the relative risk for breast cancer mortality after 13 years to be 0.80. The evidence did
not show a survival benefit of mass mammography screening. 67
Breast Cancer Outcomes and Patient Characteristics
One case-control study (n=4,569) examined how the relationship between
mammography and breast cancer outcomes differed by age. It found that the screening
mammography’s efficacy for reducing the rate of death within five years after diagnosis
was greater at ages 50-64 and for postmenopausal women than for women aged 40-49. 68
The odds ratio between those who received a screening mammography and those who
did not for breast cancer death within 5 years of diagnosis was 0.47 for women ages 5064, and 0.45 for post-menopausal women. The odds ratio of breast cancer death within 5
years of diagnosis was 0.89 for women aged 40-49 and 0.74 for premenopausal women.
62 Berry DA, Inoue L, Shen Y, et al. Modeling the impact of treatment and screening on U.S. breast cancer
mortality: a Bayesian approach. Journal of the National Cancer Institute Monographs 2006;(36):30-6.
63 Cox B. The effect of service screening on breast cancer mortality rates. Eur J Cancer Prev 2008;17(4):306-11.
64 Klemi PJ, Parvinen I, Pylkkanen L, et al. Significant improvement in breast cancer survival through
population-based mammography screening. Breast 2003;12(5):308-13.
65 Sener SF, Winchester DJ, Winchester DP, et al. Survival rates for breast cancers detected in a community
service screening mammogram program. American Journal of Surgery 2006;191(3):406-9.
66 Buseman S, Mouchawar J, Calonge N, Byers T. Mammography screening matters for young women with
breast carcinoma: evidence of downstaging among 42-49-year-old women with a history of previous
mammography screening. Cancer 2003;97(2):352-8.
67 Gotzsche PC. Screening for breast cancer. Annals of Internal Medicine 2003;138(9):769-70.
68 Norman SA, Russell LA, Weber AL, et al. Protection of mammography screening against death from
breast cancer in women aged 40-64 years. Cancer Causes & Control 2007;18(9):909-18.
19
Another modeling study had different findings. It found that breast screening from the
age of 50-69 years reduced breast cancer mortality by 5.7-8.0 percent. It also found that
starting screening at age 40 with a five to ten year delay in effect compared with starting
screening at age 50 produced a breast cancer mortality reduction of up to 10.6 percent. 69
Key Question 4: What is the evidence that recall rates differ by patient characteristic?
Twenty-three studies addressed the question of whether recall rates differ by patient
characteristics. There were 14 retrospective observational studies, five prospective
observational, one case control, one modeling, one cohort, and one retrospective crosssectional. The studies looked at recall rates and mammography outcomes by several
different patient characteristics—race and ethnicity, socioeconomic status, age,
geography, hormone therapy replacement use, and physiological traits. Some studies
focused on how patient characteristics influenced mammography cancer detection rates
rather than recall rates.
Race & Ethnicity
One retrospective cohort study (n = 6,722) examined differences in time to diagnostic
follow-up for women of different races with abnormal initial mammograms. It found
that African American and Hispanic women had longer times to follow-up (20 and 21
days, respectively) compared with non-Hispanic white women (14 days). 70
One study looked at how the woman’s socioeconomic status was related to breast cancer
and recall rates. The retrospective observational study (n = 1,901) found that women
with less than a high school education were less likely to report follow-up after an
abnormal mammogram than were women who had at least completed college. 71 The
odds of a woman with less than a high school education reporting follow-up were 0.56
compared to a woman who had at least completed college.
Age and Recall Rates
One retrospective observational study (n = 1,900) looked at differences in diagnostic
follow-up from screening mammographies by age. It found that younger women were
less likely to report diagnostic follow-up than older women. 72 Another modeling study
reported that recall rates for screening mammography remains relatively stable at 142157 per 1000 across age groups over 40. Overall, recall rates ranged from 73 per 1000 to
69 Cox B. The effect of service screening on breast cancer mortality rates. European Journal of Cancer
Prevention 2008;17(4):306-11.
70 Press R, Carrasquillo O, Sciacca RR, Giardina EG. Racial/ethnic disparities in time to follow-up after an
abnormal mammogram. Journal of Women’s Health 2008;17(6):923-30.
71 Yabroff KR, Breen N, Vernon SW, Meissner HI, Freedman AN, Ballard-Barbash R. What factors are
associated with diagnostic follow-up after abnormal mammograms? Findings from a U.S. National Survey.
Cancer Epidemiology Biomarkers & Prevention 2004;13(5):723-32.
72 Yabroff KR, Breen N, Vernon SW, Meissner HI, Freedman AN, Ballard-Barbash R. What factors are
associated with diagnostic follow-up after abnormal mammograms? Findings from a U.S. National Survey.
Cancer Epidemiology Biomarkers & Prevention 2004;13(5):723-32.
20
236 per 1000 and probably depended on radiologist performance. 73
A third study examined the extent of false positive exams (women recalled after the
screening mammography for diagnostic exams, ultrasounds, and biopsies, who did not
have cancer) among older asymptomatic women over two time periods, 1993-1995 and
1996-1998. The study found a significant difference in the rates of diagnostic testing for
each age group (67-74, 75+) by year but no clear trend towards higher or lower rates
over time. In other words, there was no clear trend toward decreasing or increasing false
positives over time for any age group. The same study found the recall rates differed
significantly between nine Surveillance, Epidemiology, and End Results Program (SEER)
sites (California, Connecticut, Atlanta, Hawaii, Iowa, Detroit, new Mexico, Utah, and
Seattle) Recall rates in 1996-1998 ranged from 4.3 percent in Connecticut to 9.6 percent in
Hawaii. 74
Hormone Replacement Therapy and Recall Rates
Many studies also examined recall rate differences between women who had hormone
replacement therapy (HRT) and those who did not. A retrospective observational study
(sample size not specified) found a higher recall rate for those who used HRT than for
those who did not use HRT. HRT users had a 6.9 percent recall rate, and non-users had a
5.6 percent recall rate. 75 One prospective observational study (n = 88,000) found that the
relative risk of false positive recall was higher for women using oestrogen-only and
oestrogen-progestagen HRT. 76 A similar survey-based study found that the efficiency
and effectiveness of mammography is lower in users of HRT, women with previous
breast surgery, and in thin women. 77 For instance, sensitivity for HRT users was 83-85
percent and sensitivity for non-users was 92 percent. HRT users had a specificity of 96.897.8 percent, and non-users had a specificity of 98.1 percent.
Lastly, a prospective observational study (n = 104,000) found among women who did
not have cancer, HRT users were more likely to have a false positive recall. The odds of
an HRT user having a false positive recall versus a non-user were 1.12. Screening
mammography sensitivity was lower in HRT users than non-users (64.8 percent vs. 77.3
percent). Specificity was 0.6 percent lower in HRT users. Among women who were
diagnosed with cancer, HRT users were more likely to have a false-negative result. 78 The
odds ratio of an HRT user having a false negative over a non-user was 1.6.
73 Keen
JD, Keen JE. How does age affect baseline screening mammography performance measures? A
decision model. Biomed Central Medical Informatics Decision Making 2008;8:40.
74 Freeman JL, Goodwin JS, Zhang D, Nattinger AB, Freeman DH, Jr. Measuring the performance of
screening mammography in community practice with Medicare claims data. Women Health 2003;37(2):1-15.
75 Vernet MM, Checa MA, Macia F, Casamitjana M, Carreras R. Influence of hormone replacement therapy
on the accuracy of screening mammography. The Breast Journal 2006;12(2):154-8.
76 Banks E, Reeves G, Beral V, et al. Influence of personal characteristics of individual women on sensitivity
and specificity of mammography in the Million Women Study: cohort study. BMJ 2004;329(7464):477.
77 Banks E, Reeves G, Beral V, et al. Hormone replacement therapy and false positive recall in the Million
Women Study: patterns of use, hormonal constituents and consistency of effect. Breast Cancer Research
2006;8(1):R8.
78 Kavanagh AM, Mitchell H, Giles GG. Hormone replacement therapy and accuracy of mammographic
screening. Lancet 2000;355(9200):270-4.
21
Physiological Characteristics and Recall Rates
Other studies examined how a woman’s health influenced mammography outcomes.
One retrospective observational study (n = 1900) found that false positives of screening
mammographies and MRIs increased when breast density was high. The odds that
women with high-density breasts went through a false-positive were 1.67 times the odds
of women without high-density breasts. 79 Another study (retrospective observational, n
= 1900) found that women in poorer health were less likely to report follow-up. 80
Cancer Detection Rates and Patient Characteristics
Most studies that examined the relationship between cancer detection rates and patient
characteristics focused on general screening mammographies. Cancer detection rate was
highest for black women who reported symptoms at screening (13.9 per 1000 vs. 7.9 per
1000 in white women). 81
Breast cancer prevalence and detection rate increased substantially with age. Another
study (n=28,944) found that age-related differences in the accuracy of mammographies
decrease with repeated examination. 82
79 Kriege
M, Brekelmans CT, Obdeijn IM, et al. Factors affecting sensitivity and specificity of screening
mammography and MRI in women with an inherited risk for breast cancer. Breast Cancer Research and
Treatment 2006;100(1):109-19.
80 Yabroff KR, Breen N, Vernon SW, Meissner HI, Freedman AN, Ballard-Barbash R. What factors are
associated with diagnostic follow-up after abnormal mammograms? Findings from a U.S. National Survey.
Cancer Epidemiology Biomarkers & Prevention 2004;13(5):723-32.
81 Gill KS, Yankaskas BC. Screening mammography performance and cancer detection among black women
and white women in community practice. Cancer 2004;100(1):139-48.
82 Van LP, Bleyen L, De BG. Age-specific accuracy of initial versus subsequent mammography screening:
results from the Ghent breast cancer-screening programme. European Journal of Cancer Prevention
2002;11(2):147-51.
22
Glossary of Commonly Used Terms
Cancer Detection Rate: number of cancers detected per 1000 screenings
Diagnostic mammography 83: an x-ray of the breast that is used to check for breast cancer
after a lump or other sign or symptom of breast cancer has been found. Signs of breast
cancer may include pain, skin thickening, nipple discharge, or a change in breast size or
shape. A diagnostic mammogram also may be used to evaluate changes found during a
screening mammogram, or to view breast tissue when it is difficult to obtain a screening
mammogram because of special circumstances, such as the presence of breast implants.
A diagnostic mammogram takes longer than a screening mammogram because it involves
more x-rays in order to obtain views of the breast from several angles. The technician
may magnify a suspicious area to produce a detailed picture that can help the doctor
make an accurate diagnosis.
False negative 84: a test result that indicates that a person does not have a specific disease
or condition when the person actually does have the disease or condition.
False positive 85: a test result that indicates that a person has a specific disease or
condition when the person actually does not have the disease or condition. For instance,
if a radiologist recalls a patient based on a screening mammography but the patient does
not have cancer, the screening mammography is a false positive.
Negative Predictive Value: probability of no disease among patients with a negative test
Odds ratio: is the ratio of the odds of an event occurring in one group to the odds of it
occurring in another group. For example, if the odds of developing cancer are 20/80 in
post-menopausal women and the odds of developing cancer are 5/95 in premenopausal women, than the odds ratio will be 4.75.
Positive Predictive Value: probability of disease among patients with a positive test
Relative Risk 86: measure of the risk of a certain event happening in one group compared
to the risk of the same event happening in another group. A relative risk of 1 means that
there is no difference between two groups in term of their risk of cancer. A relative risk
of greater than 1 means that the group exposed to a certain factor has an increased risk
of cancer. A relative risk of less than 1 means that the group exposed to a certain factor
has a decreased risk of cancer. For example, if mammography is found to have a relative
risk of breast cancer death of 0.50, it means that those who have a mammography are
less half as likely to die of breast cancer than those who do not have a mammography.
83 Screening Mammograms: Questions and Answers. Bethesda, MD: National Cancer Institute, National
Institutes of Health, 2009. Accessed May 20, 2009, at
http://www.cancer.gov/cancertopics/factsheet/detection/screening-mammograms
84 Dictionary of cancer terms. Bethesda, MD: National Cancer Institute, National Institutes of Health.
Accessed May 20, 2009, at www.cancer.gov/dictionary/
85 Ibid.
86 Ibid.
23
Screening mammography 87: an x-ray of the breast used to detect breast changes in
women who have no signs or symptoms of breast cancer. It usually involves two x-rays
of each breast. Mammograms make it possible to detect tumors that cannot be felt.
Mammograms can also find microcalcifications (tiny deposits of calcium in the breast)
that sometimes indicate the presence of breast cancer.
Sensitivity 88: the percentage of people who test positive for a specific disease among a
group of people who have the disease. No test has 100% sensitivity because some people
who have the disease will test negative for it (false negatives).
Specificity 89: the percentage of people who test negative for a specific disease among a
group of people who do not have the disease. No test is 100% specific because some
people who do not have the disease will test positive for it (false positive).
This material provided by FMQAI, the Medicare Quality Improvement Organization for Florida, an
agency of the U.S. Department of Health and Human Services, was prepared by The Lewin Group,
Imaging measure writers under contract with the Centers for Medicare & Medicaid Services (CMS).
The contents presented do not necessarily reflect CMS policy. FL2009HODT8A1411408
Screening Mammograms: Questions and Answers. Bethesda, MD: National Cancer Institute, National
Institutes of Health, 2009. Accessed May 20, 2009, at
http://www.cancer.gov/cancertopics/factsheet/detection/screening-mammograms.
88 Dictionary of cancer terms. Bethesda, MD: National Cancer Institute, National Institutes of Health.
Accessed May 20, 2009, at www.cancer.gov/dictionary/
89 Ibid.
87
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