The current study aims to provide an assessment of the impact of diabetes mellitus and its metformin treatment on the outcomes of castration-resistant prostate cancer (CRPC) within a pooled dataset of 3 clinical trials.
This is a pooled analysis of the comparator arms of 3 clinical trials (NCT00988208; NCT00273338; NCT00519285) that evaluated docetaxel/prednisone in chemotherapy-naive patients with CRPC. Overall survival according to patient subsets (nondiabetic patients, diabetic metformin patients, and diabetic non-metformin patients) was assessed using Kaplan-Meier analysis and log-rank testing. Multivariate analysis of factors affecting overall survival was then performed through Cox regression analysis.
A total of 1600 patients were enrolled into the current study, of which 147 patients were diabetic patients receiving metformin, 116 patients were diabetic patients not receiving metformin, and 1337 were nondiabetic patients. Using Kaplan-Meier analysis, no evidence for overall survival difference was found among the 3 patient subsets (diabetic metformin patients, diabetic non-metformin patients, and nondiabetic patients) (P = .908). The following factors were predictive of worse overall survival in multivariate analysis: lower hemoglobin (P < .0001), lower body mass index (P = .041), shorter docetaxel treatment (P < .0001), and higher M1 sub-stage (P = .016).
Diabetes mellitus (with or without metformin treatment) does not seem to have a significant effect on the outcomes of chemotherapy-naive patients with CRPC treated with docetaxel/prednisone. Further studies are needed to clarify the impact of metabolic syndrome on the outcomes of androgen-dependent prostate cancer.
Clinical genitourinary cancer. 2018 Sep 27 [Epub ahead of print]
Clinical Oncology Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt; Department of Oncology, University of Calgary and Tom Baker Cancer Center, Calgary, Alberta, Canada. Electronic address: .