Statin use and risk of prostate cancer and high-grade prostate cancer: results from the REDUCE study.

BACKGROUND: Statins are associated with lower PSA levels. As PSA is the primary method for prostate cancer (PC) screening, this confounds any associations between statins and risk of being diagnosed with PC. Thus, we examined the association between statins and cancer and high-grade cancer in REDUCE, where biopsies were largely PSA-independent. METHODS: Post-hoc secondary analysis of REDUCE, which was a prospective multinational randomized controlled trial of dutasteride vs placebo for 4 years among men aged 50-75 years with PSA of 2.5-10.0 ng ml(-1) and a negative biopsy at baseline, and included PSA-independent biopsies mandated at 2- and 4-years. Analyses were limited to men who underwent at least one biopsy while under study (n=6729). The association between baseline statin use and risk of overall, high-grade (Gleason ≥ 7) or low-grade (Gleason ≤ 6) PC vs no cancer was examined using multinomial logistic regression adjusting for age, race, baseline PSA, prostate volume, rectal examination findings, body mass index (BMI), comorbidities, smoking, alcohol intake and treatment arm. RESULTS: Of 6729 men who had at least one biopsy while on study, 1174 (17.5%) were taking a statin at baseline. Men taking statins were older, had lower PSA levels, higher BMI values and lower serum testosterone and dihydrotestosterone levels, though differences, were slight. Statin use was not associated with overall PC diagnosis (multivariable OR 1.05, 95% CI 0.89-1.24, P=0.54). When stratified by grade, statin use was not associated with low-grade (multivariable OR 1.03, 95% CI 0.85-1.25, P=0.75) or high-grade cancer (multivariable OR 1.11, 95% CI 0.85-1.45, P=0.46). The major limitation is the inclusion of only men with a negative baseline biopsy. CONCLUSIONS: Among men with a negative baseline biopsy and follow-up biopsies largely independent of PSA, statins were not associated with cancer or high-grade cancer.