Fecal occult blood tests and followup need to be better targeted to healthy older adults
Research Activities, November 2011
Studies of the clinical use of the fecal occult blood test (FOBT) for the detection of colon cancer suggest that a person should have a life expectancy of at least 5 years to derive survival benefit from screening. Otherwise they are only subject to the potential burdens of followup procedures and treatments stemming from a positive result. Researchers who tracked over a 7-year period a group of 211 male veterans and 1 female veteran who had received FOBTs found that only 56 percent of patients received follow-up colonoscopy. Colonoscopy found 34 significant adenomas and 6 cancers. Ten percent of patients experienced complications from colonoscopy or cancer treatment (12 of 118). Forty-six percent of those without follow-up colonoscopy died of other causes within 5 years of FOBT, while three died of colorectal cancer within 5 years. Eighty-seven percent of patients with the worst life expectancy experienced a net burden from screening compared with 70 percent with average life expectancy and only 65 percent with best life expectancy.
The researchers concluded that older patients with the best predicted life expectancy were less likely to experience a net burden from screening than those with the worst. Their study supports guidelines that recommend using life expectancy to guide colorectal cancer screening decisions in older adults, and argues against one-size-fits-all interventions that simply aim to increase overall screening and followup rates. The study was supported by the Agency for Healthcare Research and Quality (HS19468). See "Long-term outcomes following positive fecal occult blood test results in older adults. Benefits and burdens," by Christine E. Kistler, M.D., Katharine A. Kirby, M.S., Delia Lee, B.S., and others in the May 9, 2011 Archives of Internal Medicine 171(15), pp. 1344-1351.