Type 2 diabetes mellitus and risk of malignant melanoma: a systematic review and meta-analysis of cohort studies - Qi, Li; Qi, Xiaoling; Xiong, Hongyan; Liu, Qin; Li, Jinxin; Zhang, Yao; Ma, Xiangyu; Wu, Na; Liu, Qingyun; Feng, Liangui (Iranian Journal of Public Health)