Cancer screening and site-specific mortality in adults aged ≥ 65 years: A systematic review.

Abstract

e23182 Background: Cancer screening in older adults is often guided by age-based policies; however, increasing life expectancy may extend the potential window of benefit for selected individuals beyond ages recommended in current guidelines. We evaluated whether recommended cancer screening tests are associated with reductions in site-specific cancer mortality among older adults. Methods: We conducted a systematic review of studies assessing breast, colorectal, and prostate cancer screening and site-specific mortality in adults aged ≥65 years. PubMed/MEDLINE, Embase, and Scopus were searched for studies published from 2016 to 2025. Grey literature searches and manual reference screening identified additional records. Two reviewers independently screened titles/abstracts and full texts using Covidence, with disagreements resolved by consensus. Eligible studies included cohort studies and post-hoc analyses of randomized screening trials evaluating screening modalities such as mammography, colonoscopy, fecal occult blood test (FOBT/FIT), stool DNA testing, sigmoidoscopy, virtual colonoscopy, or prostate-specific antigen (PSA) testing, and reporting cancer-specific mortality outcomes. Given substantial clinical and methodological heterogeneity, results were summarized using narrative synthesis. Results: Four studies were included: three observational cohort studies and one post-hoc analysis of a randomized screening trial evaluating colorectal or prostate cancer screening in adults aged ≥65 years. Three studies of colorectal cancer screening reported reductions in colorectal cancer–specific mortality, with hazard ratios ranging from 0.34 to 0.58. Two studies also demonstrated reduced colorectal cancer incidence, including a prospective cohort study showing a 56% reduction (HR 0.44; 95% CI 0.33–0.57). Evidence suggested greater benefit for distal colorectal cancers. One U.S. Medicare-based study of annual prostate-specific antigen screening reported reduced prostate cancer–specific mortality, corresponding to approximately 2.3 fewer deaths per 1,000 men aged 67–74 years. No eligible studies of breast cancer screening met inclusion criteria. Overall risk of bias was moderate. Conclusions: Among adults aged ≥65 years, available observational evidence suggests that colorectal cancer screening is associated with substantial reductions in cancer incidence and cancer-specific mortality, while prostate cancer screening is associated with more modest mortality benefits that vary by age and comorbidity burden. These findings support individualized cancer screening decisions in older adults based on life expectancy, comorbidity, and patient preferences. Interpretation is limited by study heterogeneity and reliance on observational data. Further randomized and pragmatic studies are needed to better define the balance of benefits and harms in this population.