: Impact of Metformin on Prostate Cancer Outcomes in the E3805 CHAARTED Trial
In this study, the impact of metformin was assessed on survival outcomes of patients who were stratified to androgen deprivation therapy with docetaxel compared to androgen deprivation alone. Of the 788 patients who underwent randomization, 398 patients received ADT + docetaxel and 392 received ADT alone. 8.6% of these patients were on metformin at randomization, 39 patients in ADT + docetaxel and 29 patients in ADT alone. Median follow up was 28.9 months. Comparing ADT + docetaxel + metformin to ADT + metformin demonstrated no differences in clinicopathologic data.
Dr. Jarrard showed that after adjusting for treatment and prior local therapy with multivariate analysis, metformin was associate with a non-significant worse overall survival (HR 1.47, 95%CI 0.95-2.26). There was also no difference in prostate cancer specific survival (p=0.78). However, docetaxel use (HR 0.62, 95%CI 0.47-0.81) and prior local therapy (HR 0.56, 95%CI 0.38-0.82) were associated with improved survival outcomes.
Several hypotheses have been proposed in the past as to why metformin may have an anti-tumor effect. However, future randomized controlled prospective trials are needed to further elucidate this information for metastatic hormone sensitive patients.
Presented by: David Jarrard, MD
Authors: D Jarrard, YH Chen, G Liu, M Carducci, M Eisenberger YN Wong, N Hahn, M Kohli, M Cooney, R Dreicer, NJ Vogelzang, J Picus, D Shervin. M Hussian, J Garcia, R Dipaola, C Sweeney
Institution: Multi-institutional
Written By: David B. Cahn, DO, MBS, Fox Chase Cancer Center, Philadelphia, PA
Twitter: @dbcahn
at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA