Effects of bariatric surgery on incidence of obesity-related cancers: a meta-analysis

The aim of this meta-analysis was to investigate possible relationships between bariatric surgery and incidence of obesity-related cancers. Obesity is an established risk factor for obesity-related cancers but the effects of bariatric surgery on incidence of obesity-related cancers are uncertain. We searched 4 electronic databases to identify eligible studies: PubMed, Embase, Web of Science, and Google Scholar. Five observational studies were eligible and included in this meta-analysis. Random-effects or fixed-effects odds ratio (OR) and its corresponding 95% confidence interval (CI) were pooled. Meta-analysis of these 5 observational studies revealed that bariatric surgery was associated with a significantly (p=0.0004) reduced incidence of obesity-related cancers (OR=0.43, 95%CI, 0.27-0.69) when compared with control individuals. Pooled estimated data showed that bariatric surgery is associated with a 24% lower colorectal cancer (CRC) risk. No publication bias was detected by Egger's or Begg's tests. Although bariatric surgery may significantly reduce incidence of obesity-related cancers, considering the limitations of these included studies, these findings should be confirmed by further well-designed studies.