Type 2 diabetes mellitus represents a public health worldwide emergency and more than 300 million people in the world now have diabetes; it has been associated with cancer in general and for pancreatic cancer in particular. The question of whether diabetes mellitus type 2, is a risk factor for pancreatic cancer is complicated by the possible presence of obesity and by the medication used to treat it (insulin and metformin). We have briefly reviewed the data both for and against the possibility that pancreatic cancer is a consequence of type 2 diabetes mellitus, and whether the drugs used for this form of diabetes have a protective effect on pancreatic cancer development. We believe that more studies are necessary in order to definitively identify type 2 diabetes mellitus as a risk factor for pancreatic cancer and also as to the ability of metformin to reduce this cancer risk. Finally, the exact mechanism of metformin in preventing gastrointestinal cancer in general and pancreatic cancer in particular requires further investigation.
