Aspirin Use to Prevent Cardiovascular Disease and Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 35471507 · doi:10.1001/jama.2022.3337
What was done
Systematic review and Peto fixed-effects meta-analysis of English-language randomized clinical trials evaluating low-dose aspirin (100 mg/day or less) versus placebo or no intervention for primary cardiovascular disease and colorectal cancer prevention, searching databases through January 2021 with surveillance through January 2022 to support US Preventive Services Task Force recommendations.
What was found
Across 11 RCTs and 1 pilot trial (134,870 participants total), low-dose aspirin significantly decreased major cardiovascular events (odds ratio [OR] 0.90, 95% CI 0.85 to 0.95; 11 RCTs, n = 134,470; absolute risk reduction range -2.5% to 0.1%), but was not significantly associated with reductions in cardiovascular mortality or all-cause mortality. Low-dose aspirin significantly increased total major bleeding (OR 1.44, 95% CI 1.32 to 1.57; 10 RCTs, n = 133,194; absolute risk increase range 0.1% to 1.0%). Trial evidence for colorectal cancer benefits was limited and variable across follow-up durations, reaching statistical significance only in observational follow-up beyond randomized trial periods.
Why it matters
This updated USPSTF evidence review demonstrates that the small absolute cardiovascular event reduction achieved by routine primary-prevention aspirin is counterbalanced by an increase in major bleeding, without an overall or cardiovascular mortality benefit.
Limits
Trial findings for colorectal cancer were highly variable and dependent on post-trial observational extensions rather than primary randomized trial periods. The review was restricted to English-language trials, and abstract-level reporting does not break down effects across varying baseline cardiovascular and bleeding risk strata.
Cited by
- supports Aspirin can be useful for reducing the risk of colon cancer and heart attacks.