Postoperative outcomes after colorectal cancer surgery varied across diabetes subgroups, with worse survival and higher mortality observed in individuals with more advanced complication burden. This population-based study, published in Diabetic Medicine, analyzed 372,477 individuals diagnosed with colorectal cancer (CRC) in England between 2011 and 2021. 

Pre-existing diabetes was identified using inpatient diagnostic codes, and participants were categorized based on diabetes status and complication severity. Cox regression and logistic regression models were used to evaluate associations with postoperative outcomes, including 5-year survival, 90-day mortality, in-hospital death, and unplanned readmission. The proportion undergoing major surgical resection was lower among individuals with combined microvascular and macrovascular complications (34%) compared with those without diabetes (60%) and those with diabetes without complications (62%). 

Five-year survival after major resection was 45% in those with combined complications versus 69% in those without diabetes, and 5% versus 18% among those without major resection. Increasing complication severity was associated with higher 90-day postoperative mortality, with combined complications showing higher odds compared with no diabetes (10% vs 4%; adjusted odds ratio [OR] 2.18; 95% confidence interval [CI]: 1.90-2.51).

These findings demonstrate heterogeneity in postoperative outcomes among individuals with diabetes and CRC, with poorer outcomes observed in those with greater complication severity.