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

The study aimed to evaluate the effects of metformin on insulin, C-peptide and body weight in Chinese men undergoing androgen deprivation therapy (ADT).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.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.Metformin may be potentially efficient as a concomitant therapy on patients with PCa undergoing androgen deprivation treatment.