Colonoscopy screening may be less beneficial for average-risk patients ages 75 and older
Screening colonoscopy may provide modest benefit in colorectal cancer prevention among patients ages 70 to 74 years of age but “a smaller (if any) benefit in those who are older,” a study found.
Patients ages 75 and older at average risk for colorectal cancer may benefit less from screening colonoscopy than slightly younger patients do, according to a new study.
Researchers performed a large-scale population-based prospective study to examine the safety and effectiveness of screening colonoscopy for colorectal cancer prevention in adults ages 70 to 74 and those ages 75 to 79. For the study, observational data from Medicare beneficiaries from 2004 to 2012 were used to emulate a target trial with a colonoscopy screening group and a no-screening group. Outcome measures were 8-year risk for colorectal cancer and 30-day risk for adverse events severe enough to require hospitalization or an ED visit, classified as serious gastrointestinal, other gastrointestinal, or cardiovascular events. Results were published online Sept. 27 by Annals of Internal Medicine.
Overall, 78,065 Medicare beneficiaries were assigned to the screening group and 3,390,836 were assigned to the no-screening group, with a median follow-up of 40 months (interquartile range, 18 to 67 months). Beneficiaries ranged in age from 70 to 79 years, were at average risk for colorectal cancer, used Medicare preventive services, and had had no colonoscopies for diagnostic or surveillance purposes in the preceding 5 years. A total of 1,282 patients in the screening group (685 of those ages 70 to 74 years and 597 of those ages 75 to 79 years) and 45,530 patients in the no-screening group (21,954 of those ages 70 to 74 years and 23,576 of those ages 75 to 79 years) received a colorectal cancer diagnosis during follow-up.
Eight-year risk for colorectal cancer was 2.19% (95% CI, 2.00% to 2.37%) in those 70 to 74 years of age in the screening group and 2.62% (95% CI, 2.56% to 2.67%) in the same age range in the no-screening group (absolute risk difference, −0.42%; 95% CI, −0.24% to −0.63%). In patients 75 to 79 years of age, the 8-year risk for colorectal cancer was 2.84% (95% CI, 2.54% to 3.13%) in the screening group and 2.97% (95% CI, 2.92% to 3.03%) in the no-screening group (absolute risk difference, −0.14%; 95% CI, −0.41% to 0.16%). Patients ages 70 to 74 who underwent screening had a lower excess 30-day risk for any adverse event than patients ages 75 to 79 who underwent screening (5.6 events per 1,000 individuals [95% CI, 4.4 to 6.8] vs. 10.3 per 1,000 individuals [95% CI, 8.6 to 11.1]).
The authors noted that data on colorectal cancer-specific mortality were not available and that they included only patients who used Medicare preventive services, among other limitations. However, they concluded that screening colonoscopy provides modest benefit in colorectal cancer prevention among patients ages 70 to 74 years of age but “a smaller (if any) benefit in those who are older.” While adverse events with screening colonoscopy were uncommon in both age groups, older patients were at higher risk than younger patients.
The authors noted that their results were consistent with U.S. Preventive Services Task Force recommendations for routine screening through age 75 and individualized decisions thereafter. “Our findings may help patients, physicians, and policymakers make informed decisions about [colorectal cancer] screening,” the authors wrote.