Effect of aspirin, other NSAIDs, and statins on PSA and PSA velocity

BACKGROUND. Aspirin, other non-steroidal anti-inflammatory drugs (NSAIDs), and statins have been associated with lower risk of prostate cancer and its progression, though results have been inconsistent. METHODS. Data from 140 men with prostate cancer enrolled in a Phase 2 clinical trial of selenium to prevent prostate cancer progression were analyzed to determine association between aspirin, other NSAIDs, or statin use with baseline serum prostate-specific antigen (PSA) levels and PSA velocity (rate of PSA change over time) using repeated measures over an average follow-up time of 3.2 years. Multiple linear regression and mixed effects models were used to model the association of medication use with PSA at baseline and with PSA velocity, respectively. RESULTS. Baseline PSA levels were significantly lower in aspirin users compared to non-users (5.17 ng/ml vs. 7.58 ng/ml, P=0.001). This association was statistically significant in never smokers (aspirin users vs. non-users: 4.19 ng/ml vs. 8.24 ng/ml, P=0.004) but not in ever smokers (aspirin users vs. non-users: 5.52 ng/ml vs. 7.3 ng/ml, P=0.101). Statin and other NSAID use was not associated with baseline PSA. Aspirin, statin, or other NSAID use at baseline demonstrated a non-significant negative association with PSA velocity. CONCLUSION. These findings support an effect of aspirin use on PSA, particularly among never smokers. However, they do not suggest a protective effect on the disease and support previous findings that aspirin use may mask accurate measurement of PSA warranting consideration of washout procedures prior to testing.