The following article is part of conference coverage from the 2018 Genitourinary Cancers Symposium in San Francisco. Renal and Urology News’ staff will be reporting live on medical studies conducted by urologists and other specialists who are tops in their field in kidney stones, prostate cancer, kidney cancer, bladder cancer, enlarged prostate, and more. Check back for the latest news from GU 2018.

SAN FRANCISCO—Statins may improve overall survival among men with metastatic castration-resistant prostate cancer (mCRPC) and improve cancer-specific survival among those with high-risk prostate cancer (PCa), according to the findings of 3 studies presented at the 2018 Genitourinary Cancer Symposium.

In a post-hoc analysis of data from the randomized clinical trials COU-AA-301 and COU-AA-302, in which men with mCRPC were treated with prednisone plus placebo or abiraterone. Guillermo de Velasco, MD, PhD, of the Hospital 12 de Octubre in Madrid, Spain, and colleagues found that statin users had significantly better overall survival than non-users.

The reference group for both studies included patients in the placebo arm who did not use statins. Among statin users in the COU-AA-301 study, patients treated with prednisone plus abiraterone had a significant 29% decreased risk of death compared with the reference group. The investigators observed no significant decrease in death risk among statin users in the placebo arm.

In the COU-AA-302 study, statin users in the abiraterone and placebo groups had a significant 28% and 19% decreased risk of death, respectively, compared with the reference group.

In another study, Jacob A. Gordon, MD, of the Vancouver Prostate Centre, University of British Columbia, Vancouver, Canada, and colleagues examined the effect of statin use on outcomes among patients with mCRPC receiving abiraterone, an anti-androgen that inhibits CYP17A1. Their analysis included 301 patients. Of these, 84 (28%) were statin users. The median overall survival for statin users and non-users was 16.2 and 11.3 months, a borderline significant difference in adjusted analyses.

“Although limited by sample size, our data showed a trend that statins may mildly enhance the anti-tumor effects of [abiraterone] in CRPC patients,” the authors concluded.

The findings suggest that depletion of de novo cholesterol production may further limit androgen synthesis in concert with CYP17A1 inhibition.

In a population-based study of 12,700 men with high-risk PCa identified using the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database, Grace L. Lu-Yao, PhD, of the Sidney Kimmel Cancer Center at Jefferson Medical College and the Jefferson College of Population Health in Philadelphia, and colleagues found that post-diagnostic use of statins is associated with a 47% lower risk of PCa mortality compared with patients with no documented statin use. Among obese patients, statin use was associated with a 62% decreased risk of PCa mortality. The investigators observed a synergistic effect of statins and metformin among patients with metastatic disease.

Statin use alone by these patients was associated with a 22% decreased risk of PCa mortality, whereas concomitant use of a statin and metformin was associated with a 46% decreased risk. Notably, the study found that different statins varied in their effect, with atorvastatin appearing to offer the strongest protection. Atorvastatin users had an 82% decreased risk of PCa mortality compared with individuals who did not use statins. By comparison, use of lovastatin, pravastatin, rosuvastatin, and simvastatin was associated with a 55%, 18%, 67%, and 24% decreased risk, respectively.

This is the first human study to examine the effect of a combination of metformin and statin on PCa mortality risk, Dr Lu-Yao said.

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