Download Guidelines for breast, cervical, and colorectal cancer screening

Guidelines for breast,
cervical, and colorectal
cancer screening
FOR PRIMARY CARE PROVIDERS
09/09
to Cancer,
“ When anit Comes
ounce of
prevention and screening
is worth more than
a pound of cure.
”
Prepared for the
Waterloo Wellington Regional Cancer Program
by Red Door Wordsmithing
RedDoorWordsmithing.ca
Adapted with permission from
Cancer Care Ontario's Spotlight on:
Breast, Cervical and Colorectal Screening
presentation. February 3, 2011.
First printing June 2011.
Screening
• Evaluating screening procedures.............................................. 09
• Screening for breast, cervical, and colorectal cancer............... 11
Spotlight on breast cancer screening
• Risk of getting breast cancer..................................................... 15
• Breast cancer screening data................................................... 15
• Ontario Breast Screening Program........................................... 16
• Challenges and opportunities.................................................... 17
• Clinical case study one............................................................. 17
• Clinical case study two.............................................................. 18
• Breast cancer screening recommendations.............................. 18
Table of contents
Introduction................................................................................. 05
Cancer Care Ontario.................................................................. 06
• The role of primary care............................................................ 07
Spotlight on cervical cancer screening
• Risk of getting cervical cancer.................................................. 23
(i) General risk....................................................................... 23
(ii) The role of HPV as a necessary precursor........................ 23
(iii)HPV Vaccination................................................................ 24
• Cervical cancer screening data................................................. 25
• Ontario Cervical Screening Program........................................ 26
• Challenges and opportunities.................................................... 26
• Clinical case study one............................................................. 27
• Clinical case study two.............................................................. 28
• Clinical case study three........................................................... 28
• Cervical cancer screening recommendations........................... 29
Spotlight on colorectal cancer screening
• Risk of getting colorectal cancer
(i) General risk........................................................................ 35
(ii)Adenoma-carcinoma sequence......................................... 35
(iii)The significance of colorectal cancer location (subsite)..... 35
• Colorectal cancer screening data.............................................. 36
• ColonCancerCheck................................................................... 37
• Challenges and opportunities.................................................... 38
• Clinical case study one............................................................. 38
• Clinical case study two.............................................................. 39
• Colorectal cancer screening recommendations........................ 39
3
Introduction
Introduction
"To practice primary care well, we need to be experts
in managing complexity.” I heard a colleague say
this recently, and remarked on how true it is. Our
patients come to us with many different issues,
often with multifactorial causes. These issues need
to be managed in the context of our patients' other
illnesses, their world views on medicine and healing,
and socioeconomic considerations such as whether
they can afford or be motivated to consider
a particular treatment.
We have some help managing this complexity.
For some time there have been excellent reference handbooks available
on infectious disease protocols, immunization evidence, and multiple
other areas of family medicine. At the Waterloo Wellington Regional
Cancer Program, we decided it was time to add one further handbook.
This one is an effort to assist you by reducing the complexity surrounding
screening for cancer.
We know that screening saves lives. We know that when some cancers
are caught early in the disease process, the outcome is dramatically
altered. Treatment is simpler, and more effective. Screening is an
essential part of every primary care practice, and should be carried out in
a systematic way.
Nonetheless, cancer screening is not straightforward. It does not
offer certainty. There are false positives, and false negatives.
Evidence continues to accumulate and shift, regarding which screening
method is most appropriate, for which age group, under which
circumstances.
This handbook is a best effort to collate and interpret the standards of
care for cancer screening, as they now stand. There are clear standards
for breast, cervical, and colorectal cancer nad so we're presenting those
in this booklet. It is an evidence-based approach, taking latest statistics,
research, and policy from Cancer Care Ontario and around the world.
We hope it helps to make your job simpler, and helps to make you a
more effective clinician.
Sophie Wilson, MD, CCFP
Regional Primary Care Lead
Waterloo Wellington Regional Cancer Program
5
Cancer Care Ontario
Cancer Care Ontario
Cancer Care Ontario (CCO) is the
provincial government’s cancer advisor.
CCO is the agency responsible for continually improving services to
ensure that patients receive the right care, at the right time, from the right
person, in the right place, at every step of their journey with cancer.
CCO’s Ontario Cancer Plan III outlines steps to provide Ontarians with
the best cancer prevention, screening, and care. This plan is structured
around six goals spanning the full range of cancer care:
1. Help Ontarians lessen their risk of developing cancer.
2. Reduce the impact of cancer through effective screening and earlier detection.
3. Ensure timely access to effective diagnosis and safe,
high-quality care.
4. Improve the patient experience along every step of the cancer journey.
5. Improve the performance of Ontario’s cancer system.
6. Strengthen Ontario’s ability to improve cancer control through research.
CCO developed its Integrated Cancer Screening (ICS) strategy to
facilitate the delivery of consistent and coordinated screening to primary
care givers and patients.
The key elements of the ICS strategy are outlined below:
1. Increase patient participation in screening
• patient invitations and reminders
• patient supports and health-risk assessments
• targeted community-based outreach programs
2. Increase primary care provider performance in screening
• screening prompts and exception reports
• feedback on screening performance and change management
• change management tools and training
6
3. Establish a high-quality integrated screening strategy
• information management and information technology infrastructure
• system performance monitoring and evaluation
• quality standards
The role of primary care
The pivotal role of primary care in
reducing the incidence of cancer
and improving cancer care across
the cancer continuum is widely
recognized.1,2
The role of primary care
The CCO has three distinct screening programs: the Ontario Breast
Screening Program, the Ontario Cervical Screening Program, and
ColonCancerCheck. The ICS strategy, together with these three
screening programs, reflects CCO’s commitment to reduce the impact of
breast, cervical, and colorectal cancers by facilitating effective screening
and earlier detection.
CCO created the Primary Care
and Cancer Engagement Strategy
in 2008. Under this program,
primary care leads are recruited
from each of CCO’s regional
cancer programs across the
province. These leads give primary care providers a voice in the cancer
care system and the cancer care system a closer connection to primary
care providers.
Reducing the impact of cancer through effective screening and earlier
detection is one of CCO’s key goals. Primary care providers oversee and
influence the health and well-being of a significant portion of Ontario’s
population. They can play an important role in screening intervention by:
•systematically conducting patient risk assessments and
recommending appropriate screening based on evidence,
guidelines, and patient history
•managing the follow-up of abnormal screening test results
Research shows that decisions to screen are strongly associated with
recommendations from trusted primary care providers.3,4
7
The Role of Primary Care
8
Primary care references
1. Blackwell DL, Martinez ME, Gentleman JF. Women's compliance with public
health guidelines for mammograms and Pap tests in Canada and the United
States: an analysis of data from the Joint Canada/United States Survey of
Health. Women's Health Issues. 2008 Mar;18(2):85-99.
2. Poole B, Black C, Gelmon K, Kan L. Is Canadian women's breast cancer
screening behaviour associated with having a family doctor? Can Fam
Physician. 2010 Apr;56(4):e150-7.
3. Zarychanski R, Chen Y, Bernstein CN, Hébert PC. Frequency of colorectal
cancer screening and the impact of family physicians on screening
behaviour. CMAJ. 2007 Sep 11;177(6):593-7.
4. Zajac IT, Whibley AH, Cole SR, Byrne D, Guy J, Morcom J, et al.
Endorsement by the primary care practitioner consistently improves
participation in screening for colorectal cancer: a longitudinal analysis. J Med
Screen. 2010;17(1):19-24.
Evaluating screening
procedures
Screening
Screening
“Screening” refers to the application
of tests, examinations, or other
procedures to asymptomatic target populations in order to distinguish
between those who may have a disease and those who probably do not.1
In 1968, the World Health Organization published the following guidelines outlining the principles of screening:
1.
The condition should be an important health problem.
2.
There should be a treatment for the condition.
3.
Facilities for diagnosis and treatment should be available.
4.
There should be a latent stage of the disease.
5.
There should be a test or examination for the condition.
6.
The test should be acceptable to the population.
7.
The natural history of the disease should be adequately understood.
8.
There should be an agreed policy on whom to treat.
9.
The total cost of finding a case should be economically
balanced in relation to medical expenditure as a whole.
10.
Case-finding should be a continuous process, not just a "once and for all" project.2
Screening can be employed through either population-based methods or
case-finding methods:
•Population-based screening occurs when a test is offered
systematically to all individuals in the defined target group
within a framework of agreed upon policy, protocols, quality
management, monitoring, and evaluation.
•Case-finding screening is more opportunistic and occurs when
a test is offered to individuals without symptoms of the disease
who present to a primary care giver for reasons unrelated to that
disease.
It is important to assess the potential harms and benefits when determining whether to screen.
Just finding disease is not enough. If finding disease earlier does not
positively affect the ultimate outcome (mortality, morbidity, or quality of
life) then screening may be more harmful than beneficial. Harmful out-
9
Screening
comes include over-treatment, anxiety about screening tests, the occurrence of false positive and false negative test results, and complications
from diagnostic investigation and treatment.3,4
The U.S. Preventive Services Task Force (USPSTF) uses the following
grade definitions to assess the balance between the benefits and risks of
treatment and screening5:
Grade
Suggestions
to Practice
A
The USPSTF recommends the
service. There is high certainty
that the net benefit is
substantial.
Offer or provide this
service.
B
The USPSTF recommends the
service. There is high certainty
that the net benefit is moderate
or there is moderate certainty
that the net benefit is moderate
to substantial.
Offer or provide this
service.
C
The USPSTF recommends
against routinely providing the
service. There may be considerations that support providing the
service in an individual patient.
There is at least moderate certainty that the net benefit is small.
Offer or provide this
service only if other
considerations
support offering or
providing the
service in an
individual patient.
D
The USPSTF recommends
against the service. There is
moderate or high certainty that
the service has no net benefit
or that the harms outweigh the
benefits.
Discourage the use
of this service.
The USPSTF concludes that the
current evidence is insufficient to
assess the balance of benefits and
harms of the service. Evidence is
lacking, of poor quality, or conflicting, and the balance of benefits
and harms cannot be determined.
Read the clinical
considerations
section of the
USPSTF
Recommendation
Statement. If the
service is offered,
patients should
understand the
uncertainty about
the balance of
benefits and harms.
I Statement
10
Definition
•Sensitivity refers to the proportion of people with disease who
have a positive test result as an outcome of the screening.
•Specificity refers to the proportion of people without disease who
have a negative test result as an outcome of the screening.
Screening
It is also important to examine the accuracy of screening tests to look at
how well they perform. Screening tests must demonstrate acceptable
levels of sensitivity and specificity:
Test characteristics of sensitivity and specificity do not prove that a
screening test is efficacious. This must be shown by a demonstrated
reduction in the risk of dying from the cancer with screening. Assessing
the benefit of a screening test is based on what the USPSTF considers
the highest level of evidence — a randomized controlled trial. Submitting a screening test to rigorous randomized controlled trials is the best
way to determine whether that test will make a positive contribution to a
populations’ health.
Screening for breast, cervical, and colorectal cancer
The USPSTF and CCO’s Program in Evidence-Based Care (PEBC) have
assessed the sensitivity and specificity of screening tests used in breast,
cervical, and colorectal cancer screening:
Test
Mammography6
Sensitivity
Specificity
(Proportion of people with
disease who have a positive
test result as an outcome
of the screening.)
(Proportion of people without
disease who have a negative
test result as an outcome of
the screening.)
77 to 95 per cent
94 to 97 per cent
Less sensitive in younger
women and those with
dense breasts
Clinical breast
exam6
40 to 69 per cent
88 to 99 per cent
Pap: Liquid-Based
Cytology7
53 to 96 per cent
45 to 100 per cent
Pap: Conventional
Cytology7
35 to 94 per cent
17 to 100 per cent
gFOBT8
51 to 97 per cent
90 to 100 per cent
11
Screening
Note the similarity in sensitivity between the liquid-based cytology Pap
and the FOBT. Yet there is much better uptake of liquid-based cytology
Pap as a screening test.
The following table highlights the burden of disease for breast, cervical,
and colorectal cancer in Ontario in 20109:
Cancer
Type
Number of
new cases
Number of
deaths
Breast
8,900 (F)
2,100 (F)
Cervix
490 (F)
140 (F)
Colorectal
4,500 (M)
3,800 (F)
1,850 (M)
1,550 (F)
Cervical cancer historically had the highest mortality rate among these
three cancers. This has changed dramatically in the developed world
since the introduction of Pap tests.
12
Screening
The Ontario Breast Screening Program, the Ontario Cervical Screening
Program, and ColonCancerCheck are saving lives in Ontario. However,
screening rates for breast and cervical cancer have stalled and, although
screening rates for colorectal screening are gaining some momentum,
they are not reaching provincial targets.
New approaches are needed to increase the number of Ontarians
participating in regular screening. Specific outreach approaches need
to be developed to better engage under-screened populations. These
include First Nation, Metis, Inuit, and other aboriginal populations; new
immigrants; and low-income groups.
The effectiveness and corresponding evidence of screening can be seen
in the following chart:
Cancer site
Effectiveness of
screening
Breast
Mammography: 25 per
cent reduction in mortality
with regular screening in
50 to 69 year olds
Randomized controlled
trials10
Pap + colposcopy for
abnormal results:
Incidence reduced by
up to 80 per cent with
regular screening
Global incidence data11
FOBT + colonoscopy for
positive results: 16 per
cent reduction in mortality
with regular screening
and 20 per cent reduction
in incidence with regular
screening
Randomized controlled
trials12,13
Cervical
Colorectal
Type of studies
providing evidence
13
Screening
Screening references
1. Commission on Chronic Illness. Chronic illness in the United States. Vol I. Prevention of chronic illness. Cambridge (MA): Harvard University Press; 1957.
2. Wilson JM, Jungner G. Principles and practice of screening for disease.
Geneva: World Health Organization; 1968.
3. Trevena L. Cancer screening - pros, cons, choice, and the patient. Aust Fam
Physician. 2009 Apr;38(4):188-92.
4. Public Health Agency of Canada. Information on mammography for women
aged 40 and older: a decision aid for breast cancer screening in Canada.
Ottawa: Chronic Disease Management Division, Centre for Chronic Disease
Prevention and Control, Public Health Agency of Canada; 2009.
5. US Preventive Services Task Force. Grade definitions [Internet]. Rockville
(MD): USPSTF; 2008 [cited 2011 Mar 24]. Available from: http://www.uspreventiveservicestaskforce.org/uspstf/grades.htm
6. Nelson HD, Tyne K, Naik A, Bougatsos C, Chan BK, Humphrey L. Screening
for breast cancer: an update for the U.S. Preventive Services Task Force.
Ann Intern Med. 2009 Nov 17;151(10):727-37, W237-42.
7. McLachlin C, Mai V, Murphy J, Fung Kee Fung M, Chambers A, and members of the Cervical Screening Guidelines Development Committee of the
Ontario Cervical Screening Program and the Gynecology Cancer Disease
Site Group of Cancer Care Ontario. Cervical screening: a clinical practice
guideline [Internet]. Toronto: Program in Evidence-Based Care, Cancer Care
Ontario; 2005 May 20 [cited 2011 Mar 25]. Available from: http://www.cancercare.on.ca/common/pages/UserFile.aspx?fileId=14278
8. Rabeneck L, Zwaal C, Goodman JH, Mai V, Zamkanei M. Cancer Care Ontario guaiac fecal occult blood test (FOBT) laboratory standards: evidentiary
base and recommendations. Clin Biochem. 2008 Nov;41(16-17):1289-305.
9. Canadian Cancer Society’s Steering Committee. Canadian cancer statistics
2010 [Internet]. Toronto: Canadian Cancer Society; 2010 [cited 2011 Mar
24]. Available from: http://www.cancer.ca/Canada-wide/About%20cancer/
Cancer%20statistics/~/media/CCS/Canada%20wide/Files%20List/English%20files%20heading/pdf%20not%20in%20publications%20section/Canadian20Cancer20Statistics2020102020English.ashx
10. World Health Organization, International Agency for Research on Cancer.
Breast cancer screening. IARC handbooks of cancer prevention, volume 7.
Lyon, FR: IARC Press; 2002.
11. World Health Organization, International Agency for Research on Cancer. World
cancer report 2008. Boyle P, Levin B, editors. Lyon, FR: IARC Press; 2008.
12. Hewitson P, Glasziou P, Watson E, Towler B, Irwig L. Cochrane systematic
review of colorectal cancer screening using the fecal occult blood test (Hemoccult): an update. Am J Gastroenterol. 2008;103(6):1541-9.
14
13. Pignone M, Rich M, Teutsch SM, Berg AO, Lohr KN. Screening for colorectal cancer in adults at average risk: a summary of the evidence for the U.S.
Preventive Services Task Force. Ann Intern Med. 2002 Jul 16;137(2):132-41.
Risk of getting breast cancer
One in nine Canadian women will develop breast cancer in her lifetime.1
As women get older, their risk of getting breast cancer increases. In
Canada, 80 per cent of breast cancers are found in women over age 50
and 50 per cent of breast cancers occur in women aged 50 to 69.1
Women with a first-degree relative (mother, sister, or daughter) who has
had breast cancer are at a higher risk of developing the disease. Nearly
four per cent of women who are free from breast cancer at age 20 and
who have one first-degree relative with breast cancer will develop the
disease by the age of 50 compared to two per cent of those with no such
family history.2
It is important to put the family history risk into perspective. Most women
who develop breast cancer do not have a family history of the disease.
About three per cent of women who develop breast cancer have one or
more first-degree relatives with breast cancer, while only one per cent
have two or more first-degree relatives with the disease.1
Spotlight on breast cancer screening
Spotlight on breast cancer screening
Women aged 50 to 69 who have a breast density of 75 per cent or
greater, documented pathology of a high-risk lesion, or personal
history of ovarian cancer are also considered to be at a higher risk
of developing breast cancer.
Breast cancer screening data
Approximately 66 per cent of Ontario women aged 50 to 69 years were
screened for breast cancer in 2007/2008.
The provincial target is to increase screening rates to 70 per cent of the
target population by 2011/2012.
In 2002, the International Agency for Research on Cancer reported that
regular breast cancer screening with mammography in 50 to 69 year olds
achieved an average mortality reduction of 25 per cent.3
15
Spotlight on breast cancer screening
Ontario Breast Screening Program
Two thirds of Ontario women screened for breast cancer in 2007/2008
were screened within the Ontario Breast Screening Program (OBSP).
The OBSP is a province-wide organized screening program that ensures
asymptomatic Ontario women aged 50 and over receive the benefits of
regular mammography screening. This program is a significant contributor to earlier detection of cancer and better health outcomes.
Women aged 50 to 69 with an average risk of breast cancer are screened
biennially. Women aged 50 to 69 who have a breast density of 75 per
cent or greater, documented pathology of a high-risk lesion, personal
history of ovarian cancer, or significant family history of breast cancer are
considered to be at higher risk and may be screened annually.
OBSP features a variety of services, including:
• two-view mammography
• automatic client recall
• quality assurance for all components
• monitoring of follow-up and outcomes of clients
• program evaluation
• a comprehensive information system
• primary care provider referral or self-referral
• provision of result letters to women and their primary care provider, ensuring abnormal results go to the primary care provider first
• automatic booking of required diagnostic tests with primary care provider authorization
• generation of performance statistics for all practitioners —
including radiologists, primary care providers, and affiliate sites
The Canadian Association of Radiologists Mammogram Accreditation
Program (CAR-MAP) has developed accreditation standards for
mammography, including: equipment, image quality, and the skills and
qualifications of radiology staff.
In Ontario, there are approximately 300 mammography screening
facilities. As of April 1, 2011, there were 152 OBSP sites. All OBSP
sites are CAR-MAP accredited.
16
1.Recent data indicates that screening rates for breast cancer
have stalled. Among the target population of women aged 50 to
69, screening rates were lowest in the 50 to 54 year age group.
The provincial target is to increase screening rates to 70 per cent
of the target population by 2011/2012.
2.It is necessary to better understand under-screened population groups and the needs of ethno-cultural groups. Different
approaches may be required to engage these hard-to-reach
groups.
3.There is controversy around screening women aged 40 to 49.
CCO does not support population-based screening or widespread promotion of screening to women aged 40 to 49 for the
following reasons:
• The evidence of mortality benefit from routine
mammography for women aged 40 to 49 is not as
strong as for women aged 50 to 69.4
•The potential harms of screening mammography for
women aged 40 to 49 may outweigh the benefits.5
Spotlight on breast cancer screening
Challenges and opportunities
CCO recommends that women aged 40 to 49 talk to their health care
provider to make a personal decision about mammography.
Clinical case study one
A 42-year-old asymptomatic woman asks to be screened for breast
cancer. Her grandmother was diagnosed with breast cancer at the
age of 65.
What is your response?
Answer:
Explain that evidence shows she is not at increased risk because a
grandmother is not a first-degree relative. In addition, evidence shows
that the harms of screening may outweigh the benefits for women in
their forties.
Explain the role of healthy lifestyle choices in the prevention of breast
cancer and suggest the patient wait until she is aged 50 to begin
screening.
17
Spotlight on breast cancer screening
Clinical case study two
A 58-year-old average-risk asymptomatic patient in Erin asks if she
should go for breast screening. Her options include:
• travelling to the Waterloo Wellington Breast Centre (Grand River Hospital Freeport Site) to a new digital mammography unit
• travelling to Guelph, which is closer, to a regular
mammography unit
What is your response?
Answer:
Overall, the diagnostic accuracy of digital and film mammography as
a means of screening for breast cancer is similar.6
Explain the role of healthy lifestyle choices in the prevention of breast
cancer and advise the patient to get screening at the most convenient
location for her.
Breast cancer screening recommendations
There are four well-known screening methods for breast cancer:
18
1.
B
reast self-examination (BSE): BSE has recently been shown to
cause many false alarms and does not make a significant difference
in health outcomes. Recent evidence-based reviews do not recommend BSE.7,8 It is recommended that women of all ages learn what
is normal for their breasts and immediately report any changes to
their health care provider.
2.
C
linical breast examination (CBE): Overall, there is insufficient evidence of the effectiveness of CBE, with or without mammography,
in reducing mortality from breast cancer. CBE has higher falsepositive results and low positive predictive value compared to mammography. This may lead to unnecessary visits, imaging, biopsies,
and increased patient anxiety. A study by Chiarelli et al (2009) found
that among OBSP centres offering both CBE and mammography,
cancer detection rates and sensitivity were higher, as were referral rates and false-positive rates, compared to centres offering only
mammography. Among centres offering both CBE and mammography, for each additional cancer detected by CBE per 10,000 women
screened, there were an additional 55 false-positive results. 7,9-15
M
ammography: Evidence has found that mammography screening
reduces mortality by 25 per cent. For this reason, mammography
is the best way to find breast cancer early in women aged 50 and
older. Mammography is the only imaging modality that has been
licensed by Health Canada for breast cancer screening of the general population. Overall, the diagnostic accuracy of digital and regular film mammography as a means of screening for breast cancer is
similar. Digital mammography is more effective for women who are
under the age of 50; who are premenopausal or perimenopausal;
or who have radiographically dense breasts.8 Digital mammography
also offers the added benefits of electronic data storage and ease of
transmission.
4.
M
RI: MRI in addition to mammography has been shown to be
effective for very high-risk women.16
Spotlight on breast cancer screening
3.
19
Spotlight on breast cancer screening
20
Patient characteristics
Mammography screening
recommendations
Average-risk women under 40
Screening not recommended.
Average-risk women aged
40 to 49
Current evidence does not support
including or excluding mammography for average-risk women aged
40 to 49.
On reaching the age of 40, averagerisk women should be informed of
the potential benefits and risks of
screening mammography to make a
personal decision on when to initiate
screening.
When screening does take place,
digital mammography may be most
effective for women under the age
of 50.
Average-risk women aged
50 to 69
There is good evidence for screening average-risk women aged 50
to 69 with mammography. The best
available data support screening
every two years.
Average-risk women aged 75 +
Clinicians should help patients
assess and understand the low
benefit of mammography in this age
group. Ultimately the decision to
screen will be a personal decision
for each woman.
Women with radiographically
dense breasts, premenopausal,
and perimenopausal women
Digital mammography is more
effective than regular mammography
for women with these
characteristics.
Very high-risk women, such as
women with a BRCA1 or BRCA2
gene
Consider MRI screening in addition
to mammography. Further guidelines are pending to clarify who
qualifies and with what frequency.
For more information visit:
http://www.cancercare.on.ca/pcs/screening/breastscreening/resources/
Spotlight on breast cancer screening
Further information
Breast cancer references
1.Canadian Cancer Society’s Steering Committee. Canadian cancer statistics 2009 [Internet]. Toronto: Canadian Cancer Society; 2009 [cited 2011
Mar 24]. Available from: http://www.cancer.ca/Canada-wide/About%20
cancer/Cancer%20statistics/~/media/CCS/Canada%20wide/Files%20List/
English%20files%20heading/pdf%20not%20in%20publications%20section/
Stats%202009E%20Cdn%20Cancer.ashx
2.Cancer Care Ontario. Influence of family history and genetics on breast
cancer risk. Ontario cancer facts [Internet]. Toronto: Cancer Care Ontario;
2008 May [cited 2011 Mar 25]. Available from: http://www.cancercare.on.ca/
common/pages/UserFile.aspx?fileId=11116
3.World Health Organization, International Agency for Research on Cancer.
Breast cancer screening. IARC handbooks of cancer prevention, volume 7.
Lyon, FR: IARC Press; 2002.
4. Medical Advisory Secretariat. Screening mammography for women aged 40
to 49 years at average risk for breast cancer: an evidence-based analysis.
Ontario Health Technology Assessment Series [Internet]. Toronto: Ministry of
Health and Long-Term Care; 2007 Jan [cited 2011 Mar 24]. Available from:
http://www.health.gov.on.ca/english/providers/program/mas/tech/reviews/pdf/
rev_mammo_010107.pdf
21
Spotlight on breast cancer screening
5.Armstrong K, Moye E, Williams S, Berlin JA, Reynolds EE. Screening
mammography in women 40 to 49 years of age: a systematic review for the
American College of Physicians. Ann Intern Med. 2007 Apr 3;146(7):516-26.
6.Pisano ED, Gatsonis C, Hendrick E, Yaffe M, Baum JK, Acharyya S, et al.
Diagnostic performance of digital versus film mammography for breast-cancer screening. N Engl J Med. 2005 Oct 27;353(17):1773-83.
7.Nelson HD, Tyne K, Naik A, Bougatsos C, Chan BK, Humphrey L. Screening
for breast cancer: an update for the U.S. Preventive Services Task Force.
Ann Intern Med. 2009 Nov 17;151(10):727-37, W237-42.
8.Baxter N, Canadian Task Force on Preventive Health Care. Preventive health
care, 2001 update: should women be routinely taught breast self-examination
to screen for breast cancer? CMAJ. 2001 Jun 26;164(13):1837-46.
9.Miller AB, To T, Baines CJ, Wall C. Canadian National Breast Screening
Study-2: 13-year results of a randomized trial in women aged 50-59 years. J
Natl Cancer Inst. 2000;92:1490-9.
10.Smith, R, Saslow D, Sawyer K, et al. American Cancer Society Guidelines
for Breast Cancer Screening: Update 2003. A Cancer Journal for Clinicians.
2003;53:141-169.
11.International Agency for Research on Cancer, World Health Organization.
IARC Handbooks of Cancer Prevention: Breast Cancer Screening. IARC
Press; 2002.
12.Oestreicher N, Lehman C, Seger D, Buist D, White E. The incremental contribution of clinical breast examination to invasive cancer detection in a mammography screening program. American J Roentgenol. 2005;184(2):428-432.
13.Bancej C, Decker K, Chiarelli A, Harrison M, Turner D, Brisson J. Contribution of clinical breast examination to mammography screening in the early
detection of breast cancer. J Med Screen. 2003;10(1):16-21.
14.Kösters JP, Gøtzsche PC. Regular self-examination or clinical examination for early detection of breast cancer. Cochrane Database of Systematic
Reviews 2003, Issue 2. Art. No.: CD003373. DOI: 10.1002/14651858.
CD003373.
15.Chiarelli AM, Majpruz V, Brown P, Thériault M, Shumak R, Mai V. The Contribution of Clinical Breast Examination to the Accuracy of Breast Screening. J
Natl Cancer Inst. 2009 Sep 16;101:1236–1243.
16.Warner E, Messersmith H, Causer P, Eisen A, Shumak R, Plewes D. Magenetic resonance imaging screening of women at high risk for breast cancer:
a clinical practice guideline [Internet]. Toronto: Program in Evidence-Based
Care, Cancer Care Ontario; 2007 Apr 12 [cited 2011 Mar 25]. Available from:
http://www.cancercare.on.ca/common/pages/UserFile.aspx?fileId=37147
22
Risk of getting cervical cancer
i) General risk:
Each year in Ontario, there are up to 90,000 abnormal Pap tests and
approximately 500 women are diagnosed with cancer of the cervix.
Approximately 150 women in Ontario die from this disease every year.1
Approximately 37 per cent of invasive cervical cancers occur in women
who have never been screened.2 The median age at diagnosis is 47
years and the median age at death is 60 years.3
The incidence of cervical cancer is low for women under 25 years
of age.4,5
(ii) The role of HPV as a necessary precursor
Human Papillomavirus (HPV) is an extremely common virus usually
spread through sexual activity. There are over 120 types of HPV.6
Infection with certain types of HPV is a necessary, although not
sufficient, cause of cervical cancer.7,8
Spotlight on cervical cancer screening
Spotlight on cervical cancer screening
There are more than 15,000 new cases of HPV infection in Ontario each
year on average7. HPV is found in both men and women. The infection
usually goes away on its own, but women are less likely to clear HPV
infections as they get older.9 There is minimal risk of significant lesions
within three to five years of first HPV contact and abnormalities in young
women usually regress.10 Up to 80 per cent of women will acquire an
HPV infection in their lifetime.10-12
The risk of oncogenic HPV infection is high after the first sexual
encounter (i.e., with or without intercourse involving skin-to-skin contact),
and continues throughout a woman’s sexually active lifetime.13 Three
years after her first sexual encounter, a woman with one sexual partner
faces a 46 per cent risk of acquiring a cervical HPV infection.13
Cervical cancer and its precursors are caused by persistent infection
with high-risk forms of HPV, especially type 16 and 18. A number of
behaviours or exposures act as co-factors among women infected with
high-risk HPV, increasing the likelihood that cervical cancer will develop.
These include smoking, high parity, long-term use of hormonal contraception, and exposure to other sexually transmitted diseases, including
23
Spotlight on cervical cancer screening
herpes simplex virus type 2 [HSV-2], Chlamydia trachomatis, or human
immunodeficiency virus (HIV).14-17
(iii) HPV Vaccination
Health Canada has authorized two types of HPV vaccines that can block
HPV infections before they occur:
• G
ardasil® is a quadrivalent vaccine that protects against infection
from high-risk HPV types 16 and 18 (which cause approximately
70 per cent of cervical cancers18), and low-risk types 6 and 11
(which cause approximately 90 per cent of ano-genital warts7).
In Canada it has been approved for use with females and males
aged nine to 26.
• C
ervarix® is a bivalent vaccine that protects against high-risk HPV
types 16 and 18 only. In Canada it has been approved for use with
females aged 10 to 25.
The vaccines are given as intramuscular injections in the arm in three
doses (at 0, 2, and 6 months for Gardasil® and at 0, 1, and 6 months for
Cervarix®). The duration of protection is unknown (evidence suggests
protection for up to six years).6 Both vaccines also appear to be very
effective in preventing changes in the cells of the cervix related to their
targeted HPV types.19,20
Studies have found both Gardasil® and Cervarix® to be safe. These
vaccines contain only particles from the HPV virus and do not contain
antibiotics or preservatives such as thimerosal and mercury. Other than
some soreness around the injection site, there have been few side
effects reported.
The National Advisory Committee on Immunization (NACI) recommends
the use of Gardasil® for:
24
• females, prior to sexual intercourse, between nine and
13 years of age
• females, even after they are sexually active, who have had
previous Pap abnormalities, or have had a previous HPV
infection, between the ages of 14 and 26 years of age
Ontario’s HPV vaccination program recognizes that vaccination offers the
best protection against cervical cancer if it is received prior to HPV exposure. Since 2007, the government has provided publicly-funded voluntary
school-based immunization programs for Grade 8 girls.
It is important to note that these vaccines do not protect against all
cancer-causing HPV strains and should not replace regular cervical
cancer screening with Pap tests.
More information on Ontario’s HPV program can be found at
www.hpvontario.ca.
Cervical cancer screening data
Between 2006 and 2008, 72 per cent of Ontario women aged 20-69 were
screened.
Spotlight on cervical cancer screening
The NACI does not recommend Gardasil® for females under the age of
nine, pregnant women, or males. These recommendations are currently
under review.
The provincial target is to increase screening rates to 85 per cent by
2011/2012.
In 2008, the World Cancer Report stated that regular cervical
screening has been shown to reduce cervical cancer incidence by
up to 80 per cent.21
25
Spotlight on cervical cancer screening
Ontario Cervical Screening Program
Pap test screening is well integrated into primary care. CCO, in
partnership with the Ministry of Health and Long-Term Care, is
building on existing services and enhancing information systems to
ensure a coordinated approach to:
• education and communication
• recruitment
• provincial cervical screening information systems
• recall and follow-up
• quality assurance and improvement
• evaluation and research
The 2005 Ontario cervical screening guidelines recommend that
cervical cancer screening should be initiated within three years of first
vaginal sexual activity.22 After three consecutive annual normal Pap tests,
screening should continue every two to three years.
Screening may be discontinued after the age of 70 if there is an
adequate negative screening history in the previous 10 years (i.e., three
or more negative tests). The OCSP targets women aged 20 to 69 to
participate in regular screening, but younger and older women are also
screened, where appropriate, and in alignment with Ontario’s cervical
screening guidelines.
Aggressive follow-up of young women with abnormal screening results
is not encouraged and may be harmful. Research shows 90 per cent of
young women will clear an HPV infection within 24 months.23-27
Challenges and opportunities
26
1.Recent data indicates that screening rates for cervical cancer
have stalled. The provincial target is to increase screening rates
to 85 per cent by 2011/2012.
2.Some women are never, or rarely, screened for cervical cancer.
Under-screened women include women over 50 years old and
women who have low literacy levels; low income levels; belong
to First Nations, Metis, Inuit, and other aboriginal groups; or are
newcomers to Canada.28,29
3.There is a need for better Pap test follow-up. A 2010 study found
that 26 per cent of women with serious cervical lesions did not
receive any follow-up management Paps.30
4.HPV testing is not currently funded, but evidence increasingly
recommends its use.
5.It is important to note that HPV vaccination is not a substitute for
cervical cancer screening. Even if vaccinated, women still need
regular screening tests because the vaccine does not protect
against all cancer-causing HPV strains.
6.It is not known how vaccination programs will affect screening
programs.
7.With regular Pap tests and the HPV vaccine, it is possible to
prevent cervical cancer.
Spotlight on cervical cancer screening
Clinical case study one
A 17-year-old girl sees you to initiate the birth control pill. She started
having unprotected intercourse two months ago.
Do you do a Pap test?
Answer:
You may want to confirm when she became sexually active (i.e., with
or without intercourse involving skin-to-skin contact). You do not need
to do a Pap test at this time if the length of potential exposure to HPV
is short. A Pap test should be done within three years of initiation of
sexual activity according to the current clinical guidelines.
Explain the role of healthy lifestyle choices in the prevention of
cervical cancer.
27
Spotlight on cervical cancer screening
Clinical case study two
A 35-year-old woman has had two normal annual Pap tests.
What would your advice be to her regarding future cervical
screening?
Answer:
Explain to the patient that the current guidelines call for three
consecutive normal annual Pap tests. Thereafter, screening can be
done every two to three years.
Explain the role of healthy lifestyle choices in the prevention of
cervical cancer.
Clinical case study three
A 47-year-old woman is seen for her annual physical. She had a total
hysterectomy two years ago for benign uterine fibroids.
Do you do a Pap test?
Answer:
As long as you know her cervix was removed, there is no need to
do a Pap test. Guidelines advise to discontinue cervical screening in
women who have undergone a total hysterectomy for benign causes.
28
All women who are or have ever been sexually active should be
screened. Screening should be initiated within three years of first vaginal
sexual activity.
Aggressive follow-up of young women with abnormal screening results
may be harmful. Research shows 90 per cent of young women will clear
an HPV infection within 24 months. Thus, it may be unnecessary to treat
these young women aggressively when most will be able to clear the
HPV infection on their own if given enough time (i.e., abnormal cervical
cells may change back to normal).23-27
In addition, there is evidence that screening young women and then
treating those with cervical dysplasia is linked to adverse future pregnancy outcomes (e.g., preterm delivery, low birth weight). Thus, high
colposcopy rates in this age cohort may be associated with future harm.
The risk of developing and dying of cervical cancer increases with age.
The colposcopy follow-up rates for older women need to dramatically increase in order for older women to optimally benefit from cervical cancer
screening.23-27
Spotlight on cervical cancer screening
Cervical cancer screening recommendations
29
Spotlight on cervical cancer screening
It is recommended that women of average risk be screened annually
until there are three consecutive negative Pap tests and then continue to
be screened every two to three years. The following chart outlines Pap
screening recommendations for cervical cancer:
Patient characteristics
Pap screening
recommendations
Average-risk women with no
previous abnormal Pap including
women with subtotal hysterectomy
(with an intact cervix), pregnant
women, and women who have sex
with women
Screen annually until three
consecutive negative Paps and
then continue to screen every two
to three years.
Women who are immunocompromised (e.g., have received
transplants, HIV positive)
Screen annually.
Women who have undergone
total hysterectomy for benign
causes with no history of cervical
dysplasia
Discontinue screening.
Women over age 70
Discontinue screening if there has
been an adequate negative screening history in the previous 10 years
(i.e., three or more consecutive
negative tests).
Further information
For more information visit:
http://www.cancercare.on.ca/pcs/screening/cervscreening/hcpresources/
30
1.Canadian Cancer Society’s Steering Committee. Canadian cancer statistics
2010 [Internet]. Toronto: Canadian Cancer Society; 2010 [cited 2011 Mar
24]. Available from: http://www.cancer.ca/Canada-wide/About%20cancer/
Cancer%20statistics/~/media/CCS/Canada%20wide/Files%20List/English%20files%20heading/pdf%20not%20in%20publications%20section/
Canadian20Cancer20Statistics2020102020English.ashx
2.Spence AR, Goggin P, Franco EL. Process of care failures in invasive
cervical cancer: systematic review and meta-analysis. Prev Med. 2007
Sep;45(2-3):93-106.
3.Cancer Care Ontario. Insight on cancer: news and information on cervical
cancer. Toronto: Canadian Cancer Society (Ontario Division); 2005.
4.Screening for squamous cervical cancer: duration of low risk after negative
results of cervical cytology and its implication for screening policies. IARC
Working Group on evaluation of cervical cancer screening programmes. Br
Med J (Clin Res Ed). 1986 Sep 13;293(6548):659-664.
5.Sasieni P, Castanon A, Cuzick J. Effectiveness of cervical screening with
age: population based case-control study of prospectively recorded data.
BMJ. 2009;339:b2968.
Spotlight on cervical cancer screening
Cervical cancer references
6.Cancer Care Ontario. Perspectives on infectious agents and cancer. Toronto: Cancer Care Ontario; 2010.
7.Ontario Agency for Health Protection and Promotion. Ontario burden of
infectious disease study. Toronto: OAHPP/ICES; 2010.
8.Walboomers JM, Jacobs MV, Manos MM, Bosch FX, Kummer JA, Shah KV,
et al. Human papillomavirus is a necessary cause of invasive cervical cancer
worldwide. J Pathol. 1999;189(1):12-9.
9.Castle PE, Schiffman M, Herrero R, Hildesheim A, Rodriguez AC, Bratti MC,
et al. A prospective study of age trends in cervical human papillomavirus
acquisition and persistence in Guanacaste, Costa Rica. J Infect Dis. 2005
Jun 1;191(11):1808-1816.
10.Brown DR, Shew ML, Qadadri B, Neptune N, Vargas M, Tu W, et al. A longitudinal study of genital human papillomavirus infection in a cohort of closely
followed adolescent women. J Infect Dis. 2005;191(2):182-192.
11.Koutsky L. Epidemiology of genital human papillomavirus infection.
Am J Med. 1997 May 5;102(5A):3-8.
12.Bosch FX, de Sanjosé S. Chapter 1: Human papillomavirus and cervical
cancer--burden and assessment of causality. J Natl Cancer Inst Monographs. 2003;(31):3-13.
13.Collins S, Mazloomzadeh S, Winter H, Blomfield P, Bailey A, Young LS, et al.
High incidence of cervical human papillomavirus infection in women during
their first sexual relationship. BJOG. 2002;109(1):96-98.
31
Spotlight on cervical cancer screening
14.Ontario Agency for Health Protection and Promotion and the Institute for
Clinical Evaluative Sciences. Ontario Burden of Infectious Disease (OBOID)
Study. December 2010.
15.Bosch FX, Lorincz A, Muñoz N, Meijer CJ, Shah KV. The causal relation between human papillomavirus and cervical cancer. J Clin Pathol.
2002;55(4):244-65.
16.Bosch FX, de Sanjosé S. The epidemiology of human papillomavirus infection and cervical cancer. Dis Markers. 2007;23(4):213-27.
17.International Collaboration of Epidemiological Studies of Cervical Cancer,
Appleby P, Beral V, Berrington de González A, Colin D, Franceschi S, et al.
Carcinoma of the cervix and tobacco smoking: collaborative reanalysis of
individual data on 13,541 women with carcinoma of the cervix and 23,017
women without carcinoma of the cervix from 23 epidemiological studies. Int J
Cancer. 2006;118(6):1481-95.
18.Smith JS, Lindsay L, Hoots B, Keys J, Franceschi S, Winer R, et al. Human papillomavirus type distribution in invasive cervical cancer and highgrade cervical lesions: a meta-analysis update. Int J Cancer. 2007 Aug
1;121(3):621-632.
19.Paavonen J, Naud P, Salmerón J, Wheeler CM, Chow S-N, Apter D, et al.
Efficacy of human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine
against cervical infection and precancer caused by oncogenic HPV types
(PATRICIA): final analysis of a double-blind, randomised study in young
women. Lancet. 2009 Jul 25;374(9686):301-314.
20.Dillner J, Kjaer SK, Wheeler CM, Sigurdsson K, Iversen O-E, HernandezAvila M, et al. Four year efficacy of prophylactic human papillomavirus
quadrivalent vaccine against low grade cervical, vulvar, and vaginal
intraepithelial neoplasia and anogenital warts: randomised controlled trial.
BMJ. 2010;341:c3493.
21.Boyle P, International Agency for Research on Cancer. World cancer report
2008. Lyon: IARC Press; 2008.
22.McLachlin C, Mai V, Murphy J, Fung Kee Fung M, Chambers A, and
members of the Cervical Screening Guidelines Development Committee
of the Ontario Cervical Screening Program and the Gynecology Cancer
Disease Site Group of Cancer Care Ontario. Cervical screening: a clinical
practice guideline. Toronto: Program in Evidence-Based Care, Cancer Care
Ontario; 2005.
23.American College of Obstetricians and Gynecologists. Committee opinion number 463. Committee on Adolescent Health Care. Cervical cancer
in adolescents: screening, evaluation and management. Obstet Gynecol.
2010;116(2):469-72.
32
24.Sasieni P, Castanon A, Cuzick J. The impact of cervical screening on young
women: a critical review of the literature 2002-2009. National Health Service
Cancer Screening Programmes (NHSCSP) Publication No 31. Sheffield:
NHS Cancer Screening Programmes; 2010 Feb.
26.Bruinsma F, Lumley J, Tan J, Quinn M. Precancerous changes in the cervix
and risk of subsequent preterm birth. BJOG. 2007;114:70–80.
27.Kyrgiou M, Koliopoulos G, Martin-Hirsch P, Arbyn M, Prendiville W, Paraskevaidis E. Obstetric outcomes after conservative treatment for intraepithelial or early invasive cervical lesions: systematic review and meta-analysis.
Lancet. 2006;367:489–98.
28.Marrett LD, Chaudhry M. Cancer incidence and mortality in Ontario First
Nations, 1968-1991 (Canada). Cancer Causes Control. 2003 Apr;14(3):
259-268.
29.Ng E, Wilkins R, Fung MFK, Berthelot J-M. Cervical cancer mortality by
neighbourhood income in urban Canada from 1971 to 1996. CMAJ. 2004
May 11;170(10):1545-1549.
30.Kupets R, Paszat L. Physician and patient factors associated with follow up
of high grade dysplasias of the cervix: a population-based study. Gynecol.
Oncol. 2011;120(1):63-67.
Spotlight on cervical cancer screening
25.Arbyn M, Kyrgiou M, Simoens C, Raifu AO, Koliopoulos G, Martin-Hirsch
P, et al. Perinatal mortality and other severe adverse pregnancy outcomes
associated with treatment of cervical intraepithelial neoplasia: meta-analysis.
BMJ. 2008;337:a1284.
33
34
Risk of getting colorectal cancer
(i) General risk:
In Ontario, colorectal cancer is the third most common cancer diagnosed
and the second leading cause of cancer deaths. In 2010, an estimated
8,300 new cases were diagnosed and approximately 3,400 people died.1
Approximately 93 per cent of cases are diagnosed in people aged 50 or
older.1 Despite having a higher incidence of colorectal cancer, mortality
rates tend to be lower in Canada than in regions of Europe for both men
and women.2 The five-year survival rate for colorectal cancer has
improved over the past decade in Canada.3
Individuals with a first-degree relative (parent, sibling, or child) who has
been diagnosed with colorectal cancer are at an increased risk for the
disease. People who have conditions such as Crohn’s disease, polyps,
or colitis also have a higher risk of developing colorectal cancer.4
Spotlight on colorectal cancer screening
Spotlight on colorectal cancer screening
(ii) Adenoma-carcinoma sequence
Over 95 per cent of colorectal cancers arise from adenomatous polyps.
The progression to invasive cancer takes an average of 10 years.5
Approximately two-thirds of polyps are adenomas.6 One third are
hyperplastic with no to minimal malignancy risk. Approximately one to
five per cent of adenomatous polyps will progress to invasive cancer.
This is more likely if the polyps have high-grade dysplasia or villous
features and if they are greater than one cm.7
(iii) The significance of colorectal cancer
location (subsite)
Cancers arising from the left versus the right side of the colon have
different epidemiological, histological, and molecular features.
Tumours that are flat in appearance are more commonly located in the
right colon whereas polypoid-type tumours are more common in the left
colon. The flatter tumours on the right side are harder to detect and remove. Therefore, survival rates are lower with right versus left-sided colon
cancer. A higher proportion of right-sided colon cancers are diagnosed in
35
Spotlight on colorectal cancer screening
36
women.8 The incidence and mortality of left-sided colon cancer, but not
right-sided colon cancer, is reduced through the use of flexible sigmoidoscopy and colonoscopy respectively as screening measures.8
Colorectal cancer screening data
Fecal occult blood test (FOBT) screening rates across Ontario are
currently 30 per cent. Rates vary by region with some as high as 36 per
cent. The rate for Waterloo Wellington in 2009/2010 was 32 per cent.
The provincial target is to increase participation in biennial FOBT
screening to 40 per cent of Ontarians between the ages of 50 and 74
by the year 2011/12.
Each year, more women are screened than men. In 2007/2008, 28 per
cent of men and 31 per cent of women were screened by FOBT.
A Cochrane review reported a 16 per cent reduction in colorectal cancer
mortality with regular screening using FOBT — combined with a colonoscopy for those with a positive FOBT. In 2002, the U.S. Preventive
Services Task Force reported a 20 per cent reduction in colorectal cancer
incidence with regular screening. In three randomized controlled trials,
FOBT has been shown to reduce colorectal cancer mortality by 15 to 33
per cent. The five-year relative survival of patients diagnosed at an early
stage is 90 per cent compared to only 11 per cent for those diagnosed at
an advanced stage.9
ColonCancerCheck (CCC) is the first province-wide colorectal screening
program in Canada. The CCC program goals are to:
• reduce mortality from colorectal cancer through an organized
screening program
• improve the capacity of primary care to participate in comprehensive colorectal cancer screening
Primary care providers play a central role in promoting CCC and distributing FOBT kits. The provincial target is to screen 40 per cent of eligible
Ontarians by 2011/2012.
Key features of the CCC program include:
• colonoscopy and FOBT quality standards
• increased colonoscopy capacity across province
• primary care provider awareness
• program branded FOBT kits
• financial incentives for primary care providers
• patient correspondence
Spotlight on colorectal cancer screening
ColonCancerCheck
CCC patient correspondence as of 2010:
• Recall letters are sent to past participants who are due for repeat
biennial FOBT screening. Four months after the recall letter, a
reminder letter is sent to any participant who has not completed
screening.
• FOBT result letters are sent to all participants (FOBT normal, indeterminate, and positive). FOBT positive letters are sent to advise
participants to contact their primary care providers to discuss their
test results.
• Invitation letters are sent to Ontarians turning 50 to invite them to
discuss colorectal cancer screening with their primary care provider. Invitation letters are not sent to those who have had FOBT
activity within the past five years or a colonoscopy within the past
10 years.
Going forward, if 50 per cent of the eligible population participates in
ColonCancerCheck, it is estimated that 1,500 lives will be saved by 2020
and 5,500 lives will be saved by 2030.10
37
Spotlight on colorectal cancer screening
Challenges and opportunities
1. Screening rates need to be increased. The provincial target is to
increase participation in biennial FOBT screening to 40 per cent of
Ontarians between the ages of 50 and 74 by 2011/2012.
2. Many patients do not complete their FOBT kit. This indicates an
issue with program compliance.
3. Approximately 30 per cent of patients with positive FOBT results
do not follow-up with colonoscopy.
4. There is an ongoing debate about whether FOBT or colonoscopy
is the best tool for population-based screening.11
Clinical case study one
A 54-year-old asymptomatic male comes in for his annual physical.
What screening test would you suggest to him?
Answer:
Take his personal history to ensure he does not have a first-degree
relative with colorectal cancer or another condition such as Crohn’s
or colitis. You would also have to check that he is not symptomatic.
Colorectal cancer symptoms include:
• unexplained changes in bowel patterns
• rectal bleeding
• unexplained weight loss
• urgent feeling to empty bowel
• unexplained stool incontinence
If there is a family history or concerning symptoms, you should refer
him for a colonoscopy. Otherwise, explain the importance of screening for colorectal cancer and the use of the FOBT kit as a screening
tool.
Also explain to the patient the role of a healthy lifestyle in colorectal
cancer prevention.
38
A 47-year-old woman inquires about colorectal cancer screening.
On inquiry you find her only risk factor is that her mother was
diagnosed at age 65 with colorectal cancer.
What would you suggest?
Answer:
Explain to patient that since her mother was 65 when diagnosed, she
can wait to be screened until 50 years of age. The recommendation is
that individuals at increased risk because of a family history of colorectal cancer are screened using colonoscopy at age 4012, or 5013 ,or 10
years earlier than the age of diagnosis of their first-degree relative.
Tell the patient that she may reduce her risk of getting colorectal
cancer by leading a healthy lifestyle.
Colorectal cancer screening recommendations
There are three main screening methods for colorectal cancer: FOBT,
flexible sigmoidoscopy, and colonoscopy. More evidence is evolving on
CT colonoscopy and DNA testing.
Spotlight on colorectal cancer screening
Clinical case study two
It is recommended that people at average risk from ages 50 to 74 have
an FOBT every two years. A positive FOBT does not necessarily mean
that a person has cancer, but does indicate that a follow-up colonoscopy
is needed.
Individuals at increased risk for the disease due to a first-degree relative
with colorectal cancer should undergo an initial colonoscopy at age 4012
or 5013, or 10 years earlier than the age of any first-degree relatives at
the time of their colorectal cancer diagnosis.
The CCC has adopted Canadian Association of Gastroenterology
benchmarks for colonoscopy wait times:
• eight weeks after a positive FOBT result
• twenty-six weeks for people with a family history of colorectal
cancer14
CCO collects data on colonoscopies carried out at participating hospitals.
Regular performance reports are sent out to these hospitals.
39
Benefits may outweigh the potential risks.
Clinicians should discuss the service with eligible
patients.
FOBT screening
should be carried out
every two years.
Not recommended.
Average-risk
aged 50 to 74
Increased risk
(colorectal cancer
history, a first-degree
family history of
colorectal cancer)
People at increased
risk should be screened
using colonoscopy
starting at age 4012
or 5013, or 10 years
earlier than the age
of any first-degree
relatives at the time of
their colorectal cancer
diagnosis.
Screening not recommended.
Screening not
recommended.
Under age 50
The incidence and mortality of left-sided colon
cancer, but not right-sided colon cancer, is reduced
through the use of flexible sigmoidoscopy and
colonoscopy respectively as screening measures.
There is fair evidence to include flexible sigmoidoscopy in the periodic health examination of people
with a history of familial adenomatous polyposis.
There is insufficient evidence to make recommendations about whether only FOBT or flexible sigmoidoscopy or both tests should be performed.
The incidence and mortality of left-sided colon
cancer, but not right-sided colon cancer, is reduced
through the use of flexible sigmoidoscopy and
colonoscopy respectively as screening measures.
Flexible sigmoidoscopy
screening recommendations
FOBT screening
recommendations
There is insufficient evidence to recommend
colonoscopy for people who have a family
history of colorectal polyps or cancer but who
do not meet the criteria for hereditary
nonpolyposis colon cancer.
The incidence and mortality of left-sided colon
cancer, but not right-sided colon cancer, is
reduced through the use of flexible sigmoidoscopy and colonoscopy respectively as
screening measures.
There is fair evidence to include colonoscopy
screening in patients with a history of hereditary
nonpolyposis colon cancer.
People at increased risk should be referred
directly for a colonoscopy.
Issues with population-based screening via
colonoscopy include poor compliance, quality
of non-hospital scopes, available capacity,
potential harms of screening, and potential costs.
There is insufficient evidence to include or
exclude colonoscopy as an initial screening test.
Screening not recommended,
except for some high-risk cases.
Colonoscopy screening
recommendations
Spotlight on colorectal cancer screening
Patient
characteristics
40
For more information visit:
http://health.gov.on.ca/en/ms/coloncancercheck/pro/resources.aspx
www.ontario.ca/coloncancer.ca
Colorectal cancer references
1.Canadian Cancer Society’s Steering Committee. Canadian cancer
statistics 2010 [Internet]. Toronto: Canadian Cancer Society; 2010
[cited 2011 Mar 24]. Available from: http://www.cancer.ca/Canada-wide/
About%20cancer/Cancer%20statistics/~/media/CCS/Canada%20wide/
Files%20List/English%20files%20heading/pdf%20not%20in%20
publications%20section/Canadian20Cancer20Statistics2020102020
English.ashx
2.Ferlay J, Shin HR, Bray F, Forman D, Mathers C, Parkin DM. GLOBOCAN 2008, Cancer incidence and mortality worldwide: IARC CancerBase No. 10 [Internet]. Lyon, France: International Agency for Research
on Cancer; 2010. Available from: http://globocan.iarc.fr
3.Canadian Partnership Against Cancer. Cancer control snapshot #3:
colorectal cancer staging and survival [Internet]. Toronto: Canadian
Partnership Against Cancer; 2010 [cited 2011 Mar 24]. Available from:
http://www.cancerview.ca/idc/groups/public/documents/webcontent/
rl_crc_snapshot_three_en.pdf
Spotlight on colorectal cancer screening
Further information
4.Canadian Task Force on Preventive Health Care. Colorectal cancer
screening. Recommendation statement from the Canadian Task Force
on Preventive Health Care. CMAJ. 2001 Jul 24;165(2):206-8.
5.Bond JH. Update on colorectal polyps: management and follow-up surveillance. Endoscopy. 2003 Aug;35(8):S35-40.
6.Levin B, Lieberman DA, McFarland B, Smith RA, Brooks D, Andrews
KS, et al. Screening and surveillance for the early detection of colorectal
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