Screening colonoscopy in very elderly patients: prevalence of neoplasia and estimated impact on life expectancy.

Current guidelines do not include an upper age cutoff for colorectal cancer screening with colonoscopy. Although the prevalence of colonic neoplasia increases with age, life expectancy decreases. Thus, the benefit of screening colonoscopy in very elderly patients may be limited. To compare estimated life-years saved with screening colonoscopy in very elderly vs younger persons. Cross-sectional study conducted among 1244 asymptomatic individuals in 3 age groups (50-54 years [n = 1034], 75-79 years [n = 147], and > or =80 years [n = 63]) who underwent screening colonoscopy at a US teaching hospital and clinic. Prevalence of various types of colon neoplasia; estimated gain in life expectancy, calculated as life expectancy--(life expectancy during polyp lag time + life expectancy after colorectal cancer diagnosis); and comparison of mean gain in life expectancy across the 3 groups. Life expectancy and mortality data were derived from life tables, previous studies, and national databases. The prevalence of neoplasia was 13.8% in the 50- to 54-year-old group, 26.5% in the 75- to 79-year-old group, and 28.6% in the group aged 80 years or older. Despite higher prevalence of neoplasia in elderly patients, mean extension in life expectancy was much lower in the group aged 80 years or older than in the 50- to 54-year-old group (0.13 vs 0.85 years). In sensitivity analysis, with longer polyp lag times the mean extension in life expectancy decreased more in the elderly than in the younger patients; alternatively, if it was assumed that a smaller proportion of adenomas progress to colorectal cancer, the mean extension in life expectancy decreased less in the elderly than in the younger patients. Even though prevalence of neoplasia increases with age, screening colonoscopy in very elderly persons (aged > or =80 years) results in only 15% of the expected gain in life expectancy in younger patients. Screening colonoscopy in very elderly patients should be performed only after careful consideration of potential benefits, risks, and patient preferences.