The effect of bariatric surgery on reducing the risk of colorectal cancer: a meta-analysis of 3,233,044 patients

Published:October 11, 2022DOI:


      • Patients who underwent bariatric surgery had a 37% reduction in the risk of developing colorectal cancer compared with patients with obesity who had no surgery
      • The sub-analysis of studies with minimum 10 years of follow-up showed 32% decrease in risk of developing colorectal cancer compared with patients with obesity who had no surgery



      The published literature presents conflicting results regarding the impact of bariatric surgery on the incidence of colorectal cancer. There are important new studies that have addressed this question with longer follow-up.


      To investigate the effect of bariatric surgery on the risk of developing colorectal cancer in patients with obesity.




      PubMed and Scopus were searched for relevant articles. Articles published by November 2021 were retrieved; data were extracted according to the evidence-based PICO (population, intervention, control, outcome) model and analyzed using a random-effects model to estimate the pooled relative risk (RR) and its 95% confidence interval. The heterogeneity of studies was tested and quantified using Cochran’s Q.


      The initial search yielded 327 articles. After evaluation, 13 studies were analyzed. The thorough evaluation resulted in 13 articles, which were analyzed. A total number of 3,233,044 patients were included in the meta-analysis. The mean time of follow-up was 9.5 ± 7.9 years. The pooled estimate of the adjusted RR was .63 (95% confidence interval, .50–.79). Heterogeneity χ2 was 107.96 (df = 12; P < .001; I2 = 89%).


      Patients who underwent bariatric surgery had a 37% reduction in the risk of developing colorectal cancer compared with patients with obesity who had no surgery.


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