Download US Preventive Services Task Force

U.S. Preventive Services Task Force
Screening Guidelines for Breast Cancer:
Does it make sense? Does it help the PCP?
Melanie Royce, MD, PhD
Associate Professor, Department of Internal Medicine
Chief of the Section of Breast Oncology, Division of Hematology-Oncology
The University of New Mexico Cancer Center
Objectives
• What has changed in the new guidelines? 
Compare previous guidelines to the newly issued
breast cancer guidelines
• What is the rationale/reasoning behind the
changes?  Evaluate the science behind the
recent guidelines
• How does the change in guidelines impact
current clinical practice?  Consider additional
implications
Screening as a Public Health Prevention Tool:
Classic Criteria
• Natural history of disease  is there a detectable
preclinical phase?
• Treatment:
• Is effective treatment available?
• Is treatment more effective if initiated at a pre-symptomatic
stage? Does shift to earlier stage decrease mortality?
• Screening Test:
• Is it safe, inexpensive, acceptable?
• Does it offer good discrimination between diseased and
non-diseased?
U.S. Preventive Services Task Force
Grading of Recommendations
Grade
Certainty
Net Benefit
USPSTF
Recommendation
A
High
Substantial
Yes, routinely offer
B
High
Moderate
Yes, offer
C
Moderate/High
Small
Not routinely offered
D
Moderate/High
None
No, discourage
I
Insufficient evidence
Unknown
No recommendation
2002 Breast Cancer Screening
Recommendations
• Screening mammography every 1-2 years for all
women starting at age 40 (Grade B)
• Emphasized that doctors should inform women about
risks and benefits
• Benefits of mammography increased with age
• Breast self-exam (BSE)  insufficient evidence,
no recommendation (Grade I)
• Clinical breast exam (CBE)  insufficient
evidence, no recommendation (Grade I)
2009 Breast Cancer Screening Recommendations
Ann Intern Med 2009;151:716-726
2009 Breast Cancer Screening Recommendations
Ann Intern Med 2009;151:716-726
2009 Recommendations:
Key changes
• Women age 40-49 (Grade C):
• Should not receive routine mammography
• Decision to start screening should take into account
patient’s values re: benefits and harms
• Applies only to women of average risk
• Women age 50-74 (Grade B)  Should be screened biannually
• Women age > 75 (Grade I)
• Breast self-exam (Grade D)  Should not be taught
Rationale for age recommendations
•For most women, increasing age is the most
important risk factor for breast cancer
•Benefit for screening seems equivalent for
women 40 to 49 yrs and 50 to 59 yrs, but…
• Incidence and consequences differ between age
groups
Rationale for age recommendations
Number of women needed to invite for screening for a 10-yr
period to extend one woman’s life, by age group(decade)
NNI= Number of Women Needed to Invite
Rationale for age recommendations
•Based on data selected and using number
needed to screen to save 1 life as its metric,
the USPTFS concluded that there is:
• Moderate evidence that net benefit is small for
women aged 40-49
• Moderate certainty of moderate benefit for
women aged 50-74
• Lacking evidence for women aged >75 and
balance of benefit/harms cannot be determined
Choices Involve Value Judgments
“The ages at which … tradeoff
becomes acceptable to individuals
and society are not clearly resolved
by the available evidence”
Heidi Nelson, M.D.
University of Oregon, Evidence-Based Practice Center,
USPSTF meta-analysis first author
U.S. Preventive Services Task Force
Panel and Data Sources
• Panel involved well-respected scientists and
institutions for meta-analysis and modeling
• Panel membership was critiqued for not
including radiologists
• Data selected were best available
Screening as a Public Health Prevention Tool:
Breast Cancer as an Example
• Natural History: Detectable preclinical phase  Yes,
for some tumors, but not all
• Treatment:
• Effective treatment available  Yes, for majority of tumors
• Treatment more at pre-symptomatic stage  Early treatment
prevents metastases
• Screening Test (mammography):
• Safe, inexpensive, acceptable  Yes
• Discriminates clinically relevant disease vs. not  criteria where
mammography is weak – Why?
Screening as a Public Health Prevention Tool:
Breast Cancer as an example
• Tumor biology limits mammography as a screening test,
particularly for younger women
• Breast density, highest < 50 or pre-menopause, may
obscure a tumor on imaging
Screening as a Public Health Prevention Tool:
Breast Cancer as an Example
• Most aggressive tumors will not be caught by
screening (interval cancers, Tumor D)
• Mammography cannot identify tumors most likely to
result in mortality Overdiagnosis (Tumor B)
Esserman JAMA 2009.
Unfortunately,
None of these nuances, some of which
disproportionately affect women
aged 40 to 49, were clearly
communicated
Media Attention to Guidelines
Mammograms Provide Preview of ObamaCare
Access To Mammograms Decreased Following New
Breast Cancer Screening Guidelines.
New Breast-Cancer Screening Guidelines:
Confusion, Dismay or Relief?
New breast cancer screening guidelines
confuse women
Public Reaction to the Guidelines
• Large perception that women under age 50
should not receive a mammogram
• Related fear that health insurance companies
will stop covering mammograms for women
aged 40-49
• Breast cancer advocacy organizations
apprehensive that it would undermine their
prevention efforts
Emphasis Leads to Misconception
• “USPSTF recommends against routine screening
mammography in women aged 40 to 49 years. The
decision to start regular, biennial screening before age 50
years should be an individual one and take patient context
into account, including the patient’s values regarding
specific benefits and harms”.
• “USPSTF recommends against routine screening
mammography in women aged 40 to 49 years. The decision to
start regular, biennial screening before age 50 years should be an individual one and
take patient context into account, including the patient’s values regarding specific
benefits and harms”.
• “USPSTF recommends against screening mammography in
women aged 40 to 49 years”.
Scientifically, USPSTF recommendations
• Appear sound in terms of methodology and data used
for guideline development
• Biological reasons for differences in efficacy of
mammography for women age 40 to 49 exist
• Choice of optimal ratio for benefit/harm can be
critiqued, but that is beyond the science
We can all agree that…
• Scientific panels need assurance that guidelines can
be issued free of undue influence or pressure
• Politicized response to scientific process creates
uncomfortable tension and precedent
• Guidelines that are set under fear of reprisal is unlikely to
serve the common good
• Need to encourage thoughtful public debate about
the science and about the value judgments they
entail
Future Direction, Shift in Strategy:
Focus on Addressing Tumor Biology
• Identify markers that differentiate clinically
significant from minimal-risk breast tumors
• Identify the patients at highest risk for breast cancer
mortality before they develop cancer, and direct
prevention efforts to them
• Reduce or eliminate treatment for minimal-risk tumors
• Develop patient communication tools to support
informed decision-making about screening and
treatment
Thank you