Post-operative complications after colorectal cancer surgery increased with higher BMI

Because of conflicting evidence regarding overweight and post-operative complications, this study focused on post-operative complications and death within 30 and 90 days after curatively intended surgery for colorectal cancer and its association with BMI.

The study included all patients who had potentially curative surgery for colon or rectum cancer in Denmark from 2014 through 2018. The primary endpoint was post-operative complications within 30 days of surgery and secondary endpoints were 30- and 90-day mortality. All clinically relevant confounders were included in a multivariate analysis.

The cohort included 14,004 patients. In the multivariate logistic regression analysis, adjusting for relevant confounders, we found the odds ratio of having a surgical complication or having both a surgical and medical complication at the same time to be rising with increasing weight class. The multivariate analysis showed the odds ratio for both 30- and 90-day mortality to be higher for underweight patients and for obesity class III patients, but the rest of the patients had no significant differences in relative risk compared with normal-weight patients.

Based on our results, the risk of post-operative complications rises with increasing weight, whereas post-operative morbidity is increased only in the underweight and morbidly obese patients.

none.

The study was approved by the Danish Data Protection Agency (REG-008-2020).