Aspirin use and endometrial cancer risk: a meta-analysis and systematic review.

Background: The use of aspirin has been linked to a reduced risk of cancer at several sites, such as the breast, prostate, and colorectum. However, the evidence for this chemopreventive effect from aspirin use on endometrial cancer is conflicting, and whether an association exists is an open question.

Methods: After carrying out a database search of articles published up to December 2019, we identified 7 case-control studies and 11 cohort studies, including a total of 14,766 endometrial cancer cases. We pooled the odds ratios (ORs) in case-control studies and risk ratios (RRs) in cohort studies, and then conducted subgroup analysis based on factors such as the frequency and duration of aspirin use, and obesity.

Results: In the overall meta-analysis, we found a significant inverse association between any aspirin use and the risk of endometrial cancer both in case-control studied [pooled ORs =0.88, 95% confidence interval (CI): 0.78-0.98] and cohort studies (pooled RRs =0.86, 95% CI: 0.86-0.99). In the subgroup analysis, a negative association was observed between the maximal frequency of aspirin use and the endometrial cancer risk (pooled ORs/RRs: 0.82; 95% CI: 0.71-0.95), but no correlations were observed based on the longest duration of aspirin use or obesity.

Conclusions: Our results suggest that the use of aspirin was associated with a reduced risk of endometrial cancer, and the reduced risk was closely related to the high-frequency of use. Further randomized controlled trials (RCTs) are needed to confirm these findings.