Benefits of screening colonoscopy in very elderly

May 23 2006

Even though the prevalence of colon tumors increases with age, screening colonoscopy in patients over 80 years of age results in smaller gains in life expectancy, compared to younger patients, according to a study in the May 24/31 issue of JAMA: The Journal of the American Medical Association.

Current guidelines recommend colorectal cancer (CRC) screening for all patients 50 years or older, but do not specify an age limit above which screening is not recommended. The number of screening colonoscopies in elderly U.S. patients has increased dramatically since Medicare coverage was approved in 2001, according to background information in the article. However, some clinicians may have concerns with regard to screening extremely elderly patients, especially when an invasive procedure such as colonoscopy is used. Colonoscopy in very elderly patients is associated with lower procedural completion rates and possibly higher complication rates. In addition, very elderly patients have shorter life expectancies, potentially limiting the benefits of screening procedures. Decisions concerning undergoing a colonoscopy are being based on limited data regarding its impact on life expectancy.

Otto S. Lin, M.D., M.Sc., of Virginia Mason Medical Center, Seattle, and colleagues conducted a study to estimate the average extension in life expectancy in very elderly vs. younger patients undergoing screening colonoscopy. The study included 1,244 asymptomatic individuals in 3 age groups (50 to 54 years, n = 1,034; 75 to 79 years, n = 149; and 80 years and older, n = 63) who underwent screening colonoscopy.

The researchers found that the prevalence of colon neoplasia increased with age. Participants aged 80 years or older had a significantly higher prevalence of advanced neoplasia than the 50- to 54-year-old group (14 percent vs. 3.2 percent). Baseline average life expectancy was lower in the 2 older age groups vs. the 50- to 54-year-old group. Because of this, despite the higher prevalence of advanced neoplasia in elderly patients, the average extension of life expectancy was much lower in the 2 elderly groups. The group aged 80 years or older had a average extension of life expectancy of only 0.13 years, compared with 0.85 years for the 50- to 54-year-old group, a 6.5-fold difference.

"The results reported here show that even though the prevalence of colonic neoplasia increases with age, screening colonoscopy in very elderly patients results in only 15 percent of the expected gain in life expectancy achieved in younger patients," the authors write. "These data suggest that the benefit of screening colonoscopy in very elderly patients may be smaller than what is commonly believed. This should help individual patients and clinicians decide whether screening colonoscopy should be performed and help avoid its use in patients who are unlikely to benefit substantively."