ASCO GU 2018: Metformin and statin together may delay prostate cancer metastasis

San Francisco, CA ( Metformin and statin together may delay prostate cancer (CaP) metastasis. However, the synergistic effects on CaP mortality remain unknown. The aim of this study was to quantify individual and synergistic effects of post diagnostic statin and metformin use on CaP mortality in high risk CaP survivors.

This population-based study includes patients identified from the SEER database linked with Medicare files diagnosed with high-risk CaP (T category ≥T2c or PSA level ≥20 ng/ml or Gleason score ≥8) between 2008-2011. Hazard ratios (HR) and 95% confidence intervals were calculated using a time-varying Cox proportional hazard model with competing causes of death.

A total of 12,700 patients were included in the analysis. Post-diagnostic use of statin and metformin was associated with a substantial reduction in CaP mortality, with more pronounced effects in obese patients (HR=0.32) or M1 disease (HR=0.54). Interestingly, effects of statins vary widely by brand, with atorvastatin being associated with the largest reduction in CaP mortality (HR=0.18, 95% 0.07-0.50).

CaP mortality was substantially lower in high-risk CaP post-diagnostic users of statin within 6 years of follow-up. A synergistic effect of statin and metformin was observed in patients with M1 disease only. Prospective randomized controlled trials are required to confirm and validate these findings.

Presented by: Grace L. Lu-Yao

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, Twitter:@GoldbergHanan at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA