OBJECTIVETo explore whether bariatric surgery can decrease the incidence of obesity-related tumors in obesity patients.

METHODSRelevant studies comparing the incidence of obesity-related tumors in obesity patients between bariatric surgery and non- bariatric surgery were identified by search of PubMed, Medline, EBSCO, High Wire Press, OVID, EMbase, China hownet (CNKI) and Wanfang databases since the self-built database. In strict accordance with the standard after the screening, literature quality and extracted data were evaluated. Review manager 5.2 software was used to perform meta-analysis and sensitivity analysis. Inverted funnel chart was used to investigate the publication bias.

RESULTSFive articles including 108 954 patients were enrolled in the analysis. Among them, 26 218 cases were bariatric surgery group, and 82 736 cases of non-surgical weight loss were the control group. Meta analysis showed that bariatric surgery could obviously decrease the incidence of postoperative obesity-related tumor(RR=0.60, 95% CI:0.45-0.80, P=0.0005). Subgroup analysis showed that cancer risk difference of obesity-related tumor in male patients was not significant between two group, while the postoperative incidence of obesity-related tumor of female patients in bariatric surgery group was significantly lower compared to those female patients in control group(RR=0.68, 95% CI:0.61-0.77, P<0.01). During follow-up of 1 to 10 years, the incidence of obesity-related tumor in bariatric surgery group was significantly lower than that in control group(P<0.05). When follow-up was more than 10 years, the incidence of obesity-related tumors was similar between two groups(P=0.70).

CONCLUSIONBariatric surgery can decrease the overall risk of obesity-related cancer, especially for female patients, but with the prolongation of time, such effect of bariatric surgery is not obvious.