“…One of these cancers; prostate cancer (PCa) and diabetes mellitus (DM) are very common conditions in the contemporary ageing population. An inverse association of diabetes with prostatic cancer has been noted in several studies, which may be due to reduced testosterone levels in diabetes, altered insulin and leptin concentrations, statins and metformin use, and changes in diet and lifestyle in controlling diabetes (Kasper and Giovannucci, 2006;Avci et al, 2013;Fall et al, 2013;Demir et al, 2014). Several studies have reported decreased PCa risk among those with DM, and others found either no protective effect or even an elevated risk (Bonovas et al, 2004;Gong et al, 2006;Leitzmann et al, 2008;Hong et al, 2011;Wu et al, 2011;Long et al, 2012 lower risk of developing prostate cancer.…”