An Open-Label Pilot Study of Metformin as a Concomitant Therapy on Patients with Prostate Cancer Undergoing Androgen Deprivation Treatment.

Purpose: The study aimed to evaluate the effects of metformin on insulin, C-peptide and body weight in Chinese men undergoing androgen deprivation therapy (ADT). Methods: Between March 2013 and June 2014, 62 newly diagnosed patients of prostate cancer (PCa) due to receive ADT were recruited from 7 hospitals in Shanghai. Patients were randomized to respectively receive ADT (n = 31) and ADT + metformin (n = 31) for 6 months. Fasting and postprandial serum levels of insulin and C-peptide, blood glucose, prostate specific antigen, body mass index (BMI) and waist circumference (WC) were measured at the beginning and end of 6-month treatment. Results: Baseline characteristics were comparable between the 2 groups. Controlling for baseline levels, the ADT group had significantly higher levels of fasting glucose (p = 0.01) and higher WC (p = 0.04) than the ADT + metformin group. The levels of insulin, C-peptide and BMI did not differ significantly. Conclusions: Metformin may be potentially efficient as a concomitant therapy on patients with PCa undergoing androgen deprivation treatment.