No association between cholecystectomy and risk of colorectal cancer: a meta-analysis of cohort studies.

OBJECTIVE

Cohort studies have reported an association between colorectal cancer and cholecystectomy. However, the conclusions are inconsistent. Thus, this meta-analysis will quantify the risk of colorectal cancer following cholecystectomy.

METHODS

PubMed, EMBASE and Cochrane Library databases were searched for relevant cohort studies. The quality of individual observational studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. The relative risk of colorectal cancer after cholecystectomy was calculated using STATA 14.0 software. Subgroup and sensitivity analyses were used to examine the source of heterogeneity. Funnel plots and Egger's test were finally performed to assess the publication bias.

RESULTS

This meta-analysis included 14 studies comprising 2,283,616 subjects. Pooled analysis indicated that cholecystectomy was not a risk factor for colorectal cancer (Colorectal: RR 1.06; 95% CI 0.75-1.51, p = 0.739 Colon: RR 1.30; 95% CI 0.88-1.93, p = 0.182 Rectal: RR 0.99; 95% CI 0.74-1.32, p = 0.932). Subgroup showed that patients are at an increased risk of sigmoid colon following cholecystectomy (RR 1.42; 95% CI 1.27-1.58, p = 0.000). Furthermore, it was shown that both females and males undergoing cholecystectomy may have higher risks of colon cancer (Female: RR = 1.47, 95% CI 1.01-2.14, P = 0.042 Male: RR = 1.32; 95% CI 1.07-1.63, P = 0.010), which is similarly observed in the right colon (Female: RR 1.99; 95% CI 1.31-3.03, p = 0.001, P = 0.017 Male: RR 1.68; 95% CI 0.81-3.49, p = 0.166).

CONCLUSIONS

No clear evidence to support the association between cholecystectomy and an increased risk of colorectal cancer. For patients with valid indications, timely cholecystectomy could be performed without the risk of colorectal cancer.