1 National Cancer Institute, Rockville, MD, USA; 2 University College London, London, UK; 3 University of Texas, Houston School of Public Health, Houston, TX, USA; 4 University of Oxford, Oxford, UK; 5 Local Health Authority of Milan, Milan, Italy; 6 University of California at Los Angeles, Los Angeles, CA, USA; 7 Deutsche Klinik fur Diagnostic, Weisbaden, Germany; 8 University of Wollongong, Wollongong, Australia; 9 Group Health Cooperative, Seattle, WA, USA; 10 The Cancer Council Victoria, Carlton Victoria, Australia; 11 American Cancer Society, Atlanta, GA, USA
* Correspondence to: Dr R. Smith, American Cancer Society, 1599 Clifton Road NE, Atlanta, GA 30329, USA. Tel: +1-404-329-7610; Email: robert.smith{at}cancer.org
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Introduction |
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Statement of problem |
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Although colorectal cancer is among the most common causes of death from cancer in many countries (e.g. the second leading cause in Australia, the UK and the USA) and effective screening is available to reduce mortality, the use of these screening modalities remains low. Even in the USA, where organized efforts to increase colorectal cancer screening have been in place for almost two decades, and substantial improvements in colorectal cancer screening practices in states have been documented [1], only 32% of adults over age 50 years have had a fecal occult blood test (FOBT) in the past 2 years and only 34% say they have ever had either a sigmoidoscopy or colonoscopy for any reason [2
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The group recognized that an international perspective in addressing public education required an appreciation of the variability of colorectal cancer screening in countries throughout the world [3]. For example, public education to increase colorectal cancer screening would be inappropriate in a country without options for screening in the first place. In the sample of countries represented by the Workgroup members, five different approaches to colorectal cancer screening were taking place. In a sixth country, there was no screening whatsoever, a condition unfortunately quite frequent around the world and necessary to include in the broader perspective.
Table 1 illustrates the current status of screening in the represented countries according to whether it is organized or opportunistic. Organized screening refers to situations where a systematic approach to screening is undertaken by a governmental body or formal health-care system. Organized screening at a national level, as in Germany, exists where a national health system covers the service and some sort of central organization, management and, perhaps, evaluation is in place [4]. Regional screening programs, as in Italy, work on the same principle but only for a portion of the country. Organized screening may also be limited to specific health-care systems. In the USA some individual health maintenance organizations have adopted organized colorectal cancer screening programs for their members.
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To assist in organizing the discussion, the Workgroup used the analytic framework for strategies to promote cancer screening in communities and health-care systems formulated by the US Guide to Community Services (Figure 1) [5].
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Barriers and challenges |
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Lack of knowledge
The general level of understanding of the existence of colorectal cancer, individual risk and the benefits of colorectal cancer screening procedures is rather low even in developed countries. In some countries there is still a lack of understanding of the benefits of screening for asymptomatic disease.
Lack of provider recommendation
As with screening for breast and cervical screening, perhaps the most powerful single measure is a health provider's recommendation to get screened. Yet this is not a common practice and reflects a lack of appreciation of the benefits of screening and concerns with logistics and costs.
Multiple screening modalities
There are at least four major options for colorectal cancer screening that are included in the recommendations of major professional organizations: FOBT, sigmoidoscopy, colonoscopy and double-contrast barium enema. A full explanation of these options is too complicated for simple messages to the public or the individual patient. Methods to distill down the message to get screened by any appropriate method are still needed.
Competition with other messages
The number of evidence-based prevention recommendations appropriate for delivery in the primary care setting is increasing and includes not just cancer prevention and screening, but also advice about diet, physical activity, immunization, sexually transmitted diseases and vehicular safety. The message to adopt colorectal cancer screening is not, by far, the only message that must be heard.
Need to sustain adherence to screening
Depending on the modality, colorectal cancer screening must be repeated annually or up to every 510 years given current recommendations [6]. It is not enough for a person to be screened once; the messages appropriate to encourage a person to repeat a colorectal cancer screening test once they have experienced it the first time are not the same as getting a person to initiate the practice.
Informed decision-making
Although there is convincing evidence from controlled trials about the efficacy of both FOBT and sigmoidoscopy in reducing mortality from colorectal cancer, there are also potential harmful effects that include the physical complications of colonoscopy, stress and discomfort of testing and investigations, and the anxiety caused by false-positive screening tests. How best to delivery a succinct and effective message to inform persons being screening of both the risks and benefits of screening is a thorny problem.
Disparities by subpopulation
In countries where data for different race/ethnic, socioeconomic, geographically and age defined groups are available, differences by group in the use of colorectal cancer screening are evident. In the USA in 2000 the National Health Interview Survey reported, for example, that 34% of white respondents but only 31% of blacks and 21% of Hispanics over 50 years of age had had an FOBT within the past 2 years [7]. For sigmoidoscopy this same survey revealed that 38% of whites, 30% of blacks and 25% of Hispanics over age 50 years had ever had the procedure. The reasons for these disparities and what to do about them are not clear.
Low level of public and professional enthusiasm
Perhaps because of a lack of understanding of the benefits of colorectal cancer screening, the lack of a clear physician's recommendation, the complexity of the several options or other issues touched on above, and also because the subject of stool and the lower bowel are commonly viewed as unpleasant, there is a general lack of enthusiasm for colorectal cancer screening not seen for mammography, hypertension checks and other preventive procedures.
Facing these barriers or key issues, and keeping in mind the variety of country-specific settings for colorectal cancer screening, a number of challenges present themselves to those engaged in public education efforts. Basically, in parallel to the key issues identified above, these include:
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Recommendations |
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The second goal of the Workgroup was to identify gaps in knowledge about how best to deliver an effective public education message that can be addressed by further research. Six broad questions that must be addressed were identified that are consistent with the framework developed by the US Guide to Community Prevention Services (Figure 1).
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Summary |
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Notes |
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References |
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2. Breen N, Wagener DK, Brown ML et al. Progress in cancer screening over a decade: results of cancer screening from the 1987, 1992, and 1998 National Health Interview Surveys. J Natl Cancer Inst 2001; 93: 17041713.
3. Rozen P, Winawer SJ, Waye JD. Prospects for the worldwide control of colorectal cancer through screening. Gastrointest Endosc 2002; 55: 755759.[CrossRef][ISI][Medline]
4. Gnauck R. Screening for colon cancer in Germany. Tumori 1995; 81S: 3037.
5. Coughlin SS, Tannor B. The Cancer Systematic Review Development Team. Small media interventions: screening for breast, cervical, and colorectal cancers. Presented at the meeting of the Task Force on Community Preventive Services, Feb 26, 27 2003; Atlanta, 2003.
6. Towler BP, Irwig L, Glasziou PP et al. Screeing for colorectal cancer using the faecal occult blood test, Hemoccult (Cochrane Review). In The Cochrane Library, Issue 1. Oxford: Update Software 2002.
7. National Institutes of Health, National Cancer Institute, Cancer Information Service. Available on-line at www.cancer.gov/cis (December 10, 2002, date last accessed).