The good news from this study, said researcher Sarah Wild, is that it doesn’t seem that insulin treatment is responsible for an increased risk of some cancers, which has been a concern. Immortal time bias, time-window bias, and time-lag bias all tend to greatly exaggerate the benefits observed with a drug. We tested the hypothesis that metformin reduces the risk of cancer in people with type 2 diabetes. Liver cancer is 250 percent and pancreatic is almost 75 percent higher. For the study, the team looked at cancer incidence in more than 1 million adults at various time points and pointed to the need for a better understanding of the link between diabetes and cancer. In principle, there could be weak or strong evidence, either in favor of or against, the hypothesis that incretin-based medications can increase the risk for pancreatic, (medullary) thyroid, or other carcinomas. The general mechanism is linked to insulin resistance which is a hallmark of Type-2 diabetes.