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The U.S. Preventive Services Task Force (USPSTF), in its strongest ever recommendation for colorectal cancer screening, is urging that all adults age 50 and over get screened for the disease, the Nation's second leading cause of cancer deaths. Various screening tests are available, making it possible for patients and their clinicians to decide which test is most appropriate for each individual. The Task Force is an independent panel of experts that is sponsored by the Agency for Healthcare Research and Quality.
An estimated 143,300 U.S. adults will be diagnosed with colorectal cancer in 2002, and nearly 57,000 will die from it. Of cancer deaths, only lung cancer kills more Americans. Currently, less than half of all Americans over the age of 50 are being screened for colorectal cancer.
This recommendation strengthens the Task Force's previous position in 1996 when it simply "recommended" screening. It now "strongly recommends" screening for colorectal cancer because new studies show even more clearly that various screening methods are effective in diagnosing cancer and preventing deaths.
Although several screening tests are effective in diagnosing colorectal cancer at an early stage when it is treatable, the Task Force noted that current information is insufficient to recommend one method over another. Options include at-home fecal occult blood test (FOBT); flexible sigmoidoscopy; a combination of home FOBT and flexible sigmoidoscopy; colonoscopy; and double-contrast barium enema. Screening also can lead to early detection of adenomatous polyps, which are precancerous growths that can be removed to prevent them from progressing to cancer.
The Task Force found good evidence that annual FOBT reduces deaths from colorectal cancer and fair evidence that sigmoidoscopy alone or in combination with FOBT reduces deaths. They noted that colonoscopy or barium enema also are likely to be effective screening tools, although they did not find direct evidence that colonoscopy or barium enema are effective in reducing colorectal cancer deaths. The Task Force could not determine whether the increased accuracy of colonoscopy, which allows doctors to examine the entire colon, offsets the procedure's inconvenience, costs, and potential complications, such as a small risk for bleeding and perforation of the colon.
There is no single best test for all patients and clinical practice settings, since each test has advantages and disadvantages, according to Alfred O. Berg, M.D., M.P.H., Chair of the Task Force. Clinicians should talk to patients about the benefits and potential harms with each option. The decision to screen should be based on patient preferences and available resources for testing and followup.
Most cases of colorectal cancer occur in people at average risk for the disease, a category that includes people 50 and over. About 20 percent of colorectal cancers occur in those at high risk for the disease, including people with a personal history of ulcerative colitis or a family history of colorectal cancer in a first-degree relative; that is, a mother, father, sister, or brother who received a diagnosis before age 60. For those at high risk, the Task Force suggested that screening could begin at a younger age.
The Task Force, a leading independent panel of private-sector experts in prevention and primary care, conducts rigorous, impartial assessments of all the scientific evidence for a broad range of preventive services. Its recommendations are considered the "gold standard" for clinical preventive services. The Task Force based its conclusion on a report prepared by a research team led by Michael Pignone, M.D., M.P.H., at AHRQ's Evidence-based Practice Center at RTI International-University of North Carolina.
For more information, see the following articles in the July 16, 2002 Annals of Internal Medicine 137(2):
- "Screening for colorectal cancer: Recommendation and rationale," by the U.S. Preventive Services Task Force, pp. 129-131.
- "Cost-effectiveness analyses of colorectal cancer screening: A systematic review for the U.S. Preventive Services Task Force," by Dr. Pignone, Somnath Saha, M.D., M.P.H., Tom Hoerger, Ph.D., and Jeanne Mandelblatt, M.D., M.P.H., pp. 96-104.
- "Screening for colorectal cancer in adults at average risk: A summary of the evidence for the U.S. Preventive Services Task Force," by Dr. Pignone, Melissa Rich, M.D., Steven M. Teutsch, M.D., M.P.H., and others, pp. 132-141.
See also "Recent developments in colorectal cancer screening and prevention," by Dr. Pignone, and Bernard Levin, M.D., in the July 15, 2002, American Family Physician 66(2), pp. 297-302.
Behavioral Counseling to Promote Physical Activity. The USPSTF also has issued a recommendation on behavioral counseling for physical activity. Although the Task Force affirmed the well-established benefits and importance of physical activity to improve health and prevent disease, they found insufficient evidence to recommend for or against behavioral counseling by primary care physicians to promote physical activity among adults. In issuing their findings, the Task Force called for more research on the role of clinician counseling on levels of physical activity for adults, children, and adolescents.
The Task Force noted the abundant evidence regarding the importance of physical activity as a means to staying healthy. However, there is mixed or inconclusive evidence regarding the role of primary care providers in motivating adult patients to be physically active. There are a few multicomponent interventions that the Task Force feels are promising approaches to encouraging adults to exercise, including patient goal setting, written exercise prescriptions, individually tailored physical activity regimens, and telephone followup. In addition, the Task Force noted that linking primary care patients to community programs and targeting groups rather than individuals could be an effective approach to encourage physical activity among adults.
For more information see the August 6, 2002 Annals of Internal Medicine 137(3):
- "Behavioral counseling in primary care to promote physical activity: Recommendation and rationale," by the U.S. Preventive Services Task Force, pp. 205-207.
- "Does counseling by clinicians improve physical activity? A summary of the evidence for the U.S. Preventive Services Task Force," by Karen B. Eden, Ph.D., Tracy Orleans, Ph.D., Cynthia D. Mulrow, M.D., M.Sc., and others, pp. 208-215.
Select to access the physical activity counseling recommendation and materials for clinicians.
Hormone Replacement Therapy. Two new systematic reviews of a broad spectrum of research on hormone replacement therapy (HRT) to prevent cardiovascular disease and other long-term health problems support the findings of a recently halted clinical trial in the Women's Health Initiative (WHI). These reviews were developed for the U.S. Preventive Services Task Force as background for new recommendations on HRT use that will be published in the fall for clinicians and patients.
The two reviews found that harms could exceed benefits for women taking HRT for 5 years or longer to prevent chronic conditions. The authors of the reviews were not able to determine whether the harms or benefits depended on the type of hormones used. Although one study of estrogen and progestin in the WHI was stopped after 5 years because harms exceeded benefits, a second study of estrogen alone for women who have had a hysterectomy is continuing because the balance of benefits and harms is not yet clear.
The authors did not examine the use of HRT to treat menopausal symptoms or specific conditions such as osteoporosis.
The authors confirm the benefits of HRT to prevent bone fractures and probably colorectal cancer, but they found that the effects of HRT on dementia were uncertain. Harms include an increased risk of blood clots and stroke, an increase in breast cancer with 5 or more years of use, and a probable increase in gallbladder disease. New evidence suggests that HRT does not reduce the risk of heart disease and may modestly increase risk.
HRT, in the form of estrogen alone or combined with progestin, is taken by 14 million U.S. women. It is used by women to reduce acute symptoms of menopause such as hot flashes, and physicians have prescribed it to prevent chronic conditions such as heart disease. Heart disease is the leading cause of death among women in the United States.
The reviews were prepared for the U.S. Preventive Services Task Force by a team of researchers at AHRQ's Evidence-based Practice Center at Oregon Health & Science University. Data from the WHI trial were incorporated into the articles in an effort to integrate those results with systematic reviews of thousands of studies published on HRT since 1996. The Task Force will be reviewing these new systematic reviews in the next few months to update its 1996 recommendations on HRT.
For more information see:
- "Postmenopausal hormone replacement therapy and the primary prevention of cardiovascular disease," by Linda L. Humphrey, M.D., M.P.H., Benjamin K.S. Chan, M.S., and Harold C. Sox, M.D., in the August 20, 2002 Annals of Internal Medicine 137(4), pp. 273-284.
- "Postmenopausal hormone replacement therapy: Scientific review," by Heidi D. Nelson, M.D., M.P.H., Linda L. Humphrey, M.D., M.P.H., Peggy Nygren, M.A., and others, in the August 21, 2002 Journal of the American Medical Association 288(7), pp. 872-881.
Select to access the hormone replacement therapy recommendation and materials for clinicians.
More information on the USPSTF. Previous Task Force recommendations, summaries of the evidence, easy-to-read fact sheets explaining the recommendations, and related materials are available from the AHRQ Publications Clearinghouse.
Clinical information also is available from the National Guideline Clearinghouse™.
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