American Cancer Society Guidelines for the Early Detection of Cancer CA Cancer J Clin 2000;50:34-49 Robert A. Smith, PhD Curtis J. Mettlin, PhD Kourtney Johnston Davis, PhD Harmon Eyre, MD Abstract This issue of CA inaugurates a yearly report on American Cancer Society guidelines for early detection of cancer in asymptomatic individuals. The current recommendations, which reflect almost 20 years of updates, cover screening recommendations for breast, colorectal, prostate, and cervical cancers, as well as for other cancers, depending on patient age, history, environmental and/or occupational exposures, etc.A key concept for both the general public and health providers is the distinction between public health recommendations regarding screening and decisions about early detection tests that might be undertaken on an individual basis.Although it is likely that current screening protocols will be supplanted by newer technologies, such as genetic and molecular markers of risk and disease, greater utilization of the technologies at hand will improve efforts toward establishing an organized and systematic approach to early cancer detection. (CA Cancer J Clin 2000;50:34-49.) Introduction In the late 1970s, the American Cancer Society (ACS) embarked upon an evidence-based assessment of tests for the early detection of cancer in asymptomatic individuals. Based on the results, Guidelines for the Cancer-Related Check- up: Recommendations and Rationale was published in 1980.1 In the ensuing years, guidelines for routine screening have changed as new data have become available. Early Detection of Breast Cancer Since 1977, ACS guidelines for the early detection of breast cancer have been updated five times, most recently in 19924 and 1997.4-6 The genesis of the 1997 update was increasing evidence in the literature that the detectable preclinical phase (i.e., the sojourn time) for breast cancer had a shorter duration in premenopausal women compared with postmenopausal women. Data from the Two-County study estimated mean sojourn times for women between the ages of 40 and 49 at 1.7 years, compared with more than 3.3 years for women older than age 50.7,8 These findings, coupled with accumulating data on the value of screening for premenopausal women, indicated that the recommendation originally made in 1983, namely that women ages 40 to 49 undergo mammography every one to two years, should be reconsidered, as it was not consistent with accumulating evidence on tumor growth rates in premenopausal women. While there had been compelling evidence over the years for the value of screening women between 40 and 49 years of age for breast cancer, it was more inferential compared with the evidence of benefit among women between 50 and 69 years of age. Prior to 1997, no single trial had shown a statistically significant reduction in breast cancer deaths among women between 40 and 49, whereas two trials had shown a statistically significant benefit for women aged 50 and older. Between 1995 and 1997, however, new analyses of Swedish clinical trial data and meta-analyses taking advantage of longer periods of follow-up showed increasing benefits for women in their 40s, some of whom were randomized to receive an invitation for breast cancer screening. Meta-analyses of all trial data, with average follow-up of 12.7 years, resulted in a relative risk (RR) of 0.82 (18% fewer breast cancer deaths in the study group), and a RR of 0.71 (29% fewer deaths in the study group) for all five Swedish randomized controlled trials.9 Each point estimate was statistically significant at the 95% confidence level, although the all-trial meta-analysis had the lowest RR for breast cancer mortality due to the excess rate of breast cancer deaths among control group women in the Canadian National Breast Screening Study. The meta-analysis of Swedish trials was undertaken because those studies were both contemporary and homogenous. In addition, each meta-analysis included two second-generation trials, i.e., Gothenburg and Malmö, which applied more advanced screening protocols and observed 44% and 36% fewer breast cancer deaths, respectively, in the invited groups compared with the control groups. At this time, both meta-analyses and two individual trials have shown a statistically significant reduction in breast cancer mortality for women who were between 40 and 49 years old at randomization. The consistency of results in the other meta-analyses and the recent results from Gothenburg and Malmö, indicate that the potential benefit of screening for pre- versus postmenopausal women is more similar than different. Further, more recent analyses of trial data have provided important insights about screening in different age groups of women and have shown that the wide screening interval used to screen all women was less effective for those younger than 50 years of age.10-12 ACS Recommendations The ACS currently recommends that women begin monthly breast self-examination (BSE) at age 20. Between ages 20 and 39, women should have a clinical breast examination (CBE) every three years, and beginning at age 40, women should have an annual mammogram and CBE (Table 2). (The ACS withdrew its recommendation for a baseline examination between the ages of 35 and 40 at the time of the previous guidelines update.5) The ACS also stressed in the updated guidelines that CBE should take place prior to mammography and, ideally, there should be a short interval between the timing of the two examinations. CBE should be performed prior to mammography because if a mass is identified, it can be brought to the attention of the radiologist. Conversely, if CBE follows mammography and a mass is detected that was not seen on the mammogram, then the patient would need to return for additional directed imaging. There is also the risk that the recent mammogram may offer some false sense of reassurance that a subsequent palpable mass is not worrisome if it wasn't seen on the mammogram.13 There is no upper age limit on the ACS breast cancer screening guidelines as long as a woman is in good health. Women at significantly higher risk for breast cancer should talk with their health care providers about initiating screening earlier. Recommendations were recently developed by the Cancer Genetics Studies Consortium14 for women at higher risk for breast cancer due to significant family history. References 1. American Cancer Society: Guidelines for the cancer-related checkup: Recommendations and rationale. CA Cancer J Clin 1980;30:4-50. 2. Fink D: Guidelines for the cancer-related checkup. Atlanta, American Cancer Society, 1991. 3. Rimer BK, Bluman LG: The psychosocial consequences of mammography. J Natl Cancer Inst Monog 1997;22:131-138. 4. Dodd GD: American Cancer Society guidelines on screening for breast cancer: An overview. Cancer 1992;69(7 Suppl):1885-7. 5. Leitch AM, et al: American Cancer Society guidelines for the early detection of breast cancer: Update 1997. CA Cancer J Clin 1997;47:150-153. 6. Smith RA:. Breast cancer screening guidelines. Womens Health Issues. 1992;2:212-217. 7. Tabar L, et al: Efficacy of breast cancer screening by age: New results from the Swedish Two-County Trial. Cancer 1995;75:2507-2517. 8. Tabar L, et al: Tumour development, histology and grade of breast cancers: Prognosis and progression. Int J Cancer 1996;66:413-419. 9. Hendrick RE, et al: Benefit of screening mammography in women aged 40-49: A new meta-analysis of randomized controlled trials. J Natl Cancer Inst Monogr 1997;22:87-92. 10. Tabar L, et al: The natural history of breast carcinoma: What have we learned from screening? Cancer 1999;86:449-462. 11. Tabar L, et al: Recent results from the Swedish Two-County Trial: The effects of age, histologic type, and mode of detection on the efficacy of breast cancer screening. J Natl Cancer Inst Monogr 1997;22:43-47. 12. Swedish Cancer Society and the Swedish National Board of Health and Welfare: Breast cancer screening with mammography in women aged 40-49 years. Int J Cancer 1996;68:693-699. 13. Bassett L, et al: Quality Determinants of Mammography. Clinical Practice Guideline No. 13. Rockville, MD: Agency for Health Care Policy and Research, Public Health Service, U.S. Department of Health and Human Services, 1994; 1994. 14. Burke W, et al: Recommendations for follow-up care of individuals with an inherited predisposition to cancer: I. Hereditary nonpolyposis colon cancer: Cancer Genetics Studies Consortium. JAMA 1997;277:915-919. Radiology, 2/02 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.