Genetic polymorphisms in human UDP-glucuronosyltransferases 1A7 and the risk of gastrointestinal carcinomas: A systematic review and network meta-analysis

// Yingshi Zhang 1, 2, 3, * , Jun Hou 4, * , Fan Feng 4, * , Dandan Li 2, 3 , Qiyu Jiang 4 , Xiaojuan Li 4 , Qingchun Zhao 2, 3 and Bo-An Li 1 1 Center for Clinical Laboratory, The 302nd Hospital of Chinese PLA, Beijing 100039, P.R. China 2 Department of Pharmacy, General Hospital of Shenyang Military Area Command, Shenyang 110840, P.R. China 3 Department of Clinical Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, P.R. China 4 Research Center for Clinical and Transitional Medicine, The 302nd Hospital of Chinese PLA, Beijing 100039, P.R. China * These authors contributed equally to this work Correspondence to: Bo-An Li, email: lba@263.net Qingchun Zhao, email: zhaoqingchun1967@163.com Keywords: UDP-glucuronosyltransferases 1A7, polymorphism, gastrointestinal carcinoma, cancer, network meta-analysis Received: May 16, 2017 Accepted: May 29, 2017 Published: June 27, 2017 ABSTRACT Objective: To identify the association between gastrointestinal carcinomas (GIC) risk and UDP-glucuronosyltransferases (UGTs) 1A7 polymorphisms through a systematic review and network meta-analysis. Results: Seventeen studies were eligible, which included 7738 patients and 18 analyses. First, it was found that compared with non-cancer participants, UGT1A7*1 were significantly decreased in cancer patient groups, especially in hepatocellular carcinoma, colorectal carcinoma, and Asian population groups; UGT1A7*2 was significantly increased in hepatocellular carcinoma and Asian population groups; and UGT1A7*3 was significantly increased in hepatocellular carcinoma, colorectal carcinoma, Caucasian, and Asian population groups. Second, the UGT1A7 polymorphism alleles contrast model and the categorized UGT 1A7 genotypes were compared, and the outcomes revealed that the ratio of UGT1A7*3 vs *2 increased, which may indicate an increased risk for cancer, especially for the pancreatic carcinoma and Caucasian groups. The ratio of Intermediate vs Low increased as well, which may also indicate an increased risk for GIC. Materials and Methods: PubMed, Embase, and the Cochrane library were searched for publications up until May 2017. First, the UGT 1A7 gene polymorphisms genotype in GIC patients were compared with a non-cancer control group, and second, the UGT1A7 polymorphism alleles contrast model and UGT 1A7 genotypes categorized according to enzymatic activity were examined. Conclusions: There is a cancer risk associated with increased UGT1A7 *2 for the hepatocellular carcinoma and Asian groups and with increased UGT1A7 *3 for the hepatocellular carcinoma, colorectal carcinoma, Caucasian, and Asian groups. Moreover, in Caucasian patients with GIC, the ratio of UGT1A7 *3 vs *2 was increased.