INS and hepatocellular carcinoma: Although diabetes increases the incidence of various types of cancer [80,81], including colorectal cancer [82], gastric cancer [83], hepatocellular carcinoma [84], lung cancer [85], leukemia [86], meningioma [87], prostate cancer [52], ovarian cancer [88], and breast cancer [89], a 2006 report by Bowker et al. stated that cancer mortality rates vary depending on the type of diabetes treatment, with data from 10,309 diabetic patients showing that the metformin-using group had significantly lower cancer mortality rates than the sulfonylurea-using and exogenous insulin-using groups [90].