Purpose: A recent meta-analysis showed aspirin was associated with reduced prostate cancer (PC) risk. As anti-inflammatory medications lower PSA levels, whether these findings reflect reduced PC detection or lower PC risk is unknown. We tested the association between aspirin and non-aspirin NSAID on PC diagnosis in REDUCE, where all men received biopsies at 2- and 4-years largely independent of PSA. REDUCE tested dutasteride for PC risk reduction in men with a PSA of 2.5-10.0 ng/mL and a negative pre-study biopsy. Experimental Design: We examined the association between aspirin, NSAID or both and total, low-grade (Gleason<7), or high-grade (Gleason≥7) PC vs. no PC using multinomial logistic regression among 6,390 men who underwent ≥1 on-study biopsy. Multivariable analyses were adjusted for age, race, geographic region, PSA, prostate volume, digital rectal examination, BMI, treatment arm, smoking, alcohol, statins, hypertension, diabetes and cardiovascular disease. Results: Overall, 3,169 men (50%) were non-users, 1,368 (21%) used aspirin, 1,176 (18%) used NSAID, and 677 (11%) used both. In unadjusted models, aspirin was associated with reduced PC risk (OR=0.85, p=0.036). In multivariable analyses, aspirin was associated with reduced total PC risk (OR=0.81, p=0.015). Use of NSAID or NSAIDs and aspirin was not associated with total, low- or high-grade PC, though all ORs were <1 (all p>0.08). Therefore, we created a dichotomous variable of aspirin and/or NSAID user vs. not. On multivariable analysis, the use of aspirin and/or NSAID was significantly associated with decreased total (OR=0.87, p=0.030) and high-grade (OR=0.80, p=0.040), but not with low-grade PC risk (OR=0.90, p=0.15).
- Received August 29, 2014.
- Revision received November 21, 2014.
- Accepted December 8, 2014.
- Copyright © 2014, American Association for Cancer Research.