Outcome of rectal cancer surgery in obese and nonobese patients: a meta-analysis

BACKGROUND The escalating global epidemic of obesity is of worldwide concern because of its association with serious negative effects on health. The technical difficulty of rectal cancer surgery is exacerbated in obese patients, which may compromise outcomes. High-quality, relevant evidence is limited. This meta-analysis aims to assess the outcomes of rectal cancer surgery in obese and nonobese patients. METHODS The electronic databases Pubmed, Medline, Embase, Web of Science, and the Cochrane Library were used to search for articles that evaluated the outcomes of rectal cancer surgery in obese and nonobese patients. Fixed-effects and random-effects models were used to calculate the combined overall effect sizes of pooled data. Data are presented as odds ratios (OR) or weighted mean differences (WMD) with 95% confidence intervals (CIs). RESULTS Ten appropriate observational studies were identified from 290 published articles. In the obese group, conversion rates (OR 2.78; 95% CI 1.67-4.61), overall morbidity (OR 1.36; 95% CI 1.25-1.47), anastomotic leak (OR 3.94; 95% CI 1.88-8.24), wound infection (OR 2.22; 95% CI 1.47, 3.36), and pulmonary events (OR 2.10; 95% CI 1.18, 3.74) were all significantly increased. For pathological results, no statistical differences in the number of harvested lymph nodes and the positive margin were noted between the two groups. CONCLUSIONS Based on a meta-analysis, obesity increases the conversion rate and postoperative morbidity of rectal cancer surgery but does not influence pathological results.