Diabetes mellitus and risk of pancreatic cancer in China: A meta-analysis based on 26 case-control studies.

•The relation between diabetes mellitus and pancreatic cancer risk from many publications concluded inconsistent results.•Whether the association differs between populations from different ethnic backgrounds remains unknown.•This meta-analysis assessed the relationship between diabetes mellitus and risk of pancreatic cancer in China.•The subgroup analysis with respect to geographic area and control sources was performed.•This study included a larger number of studies which were conducted in Chinese populations.