Factors Associated with Severe Postoperative Complications (Clavien-Dindo Grades III-IV) After Left-Sided Colon Cancer Surgery: A Single-Centre Retrospective Cohort Study.

Postoperative morbidity remains a significant challenge in the surgical treatment of colorectal cancer. Nevertheless, studies specifically evaluating short-term postoperative morbidity following left-sided colon cancer surgery are limited, and the factors associated with adverse postoperative outcomes have not yet been fully characterised. This study investigates factors associated with severe postoperative complications following left-sided colon cancer surgery. A retrospective, single-centre cohort study was conducted, including 234 consecutive adult patients who underwent curative or palliative surgery for histologically confirmed left-sided colon cancer between January 2018 and December 2024. Demographic, clinicopathological, laboratory, and surgical variables were collected. Univariate binomial logistic regression and Firth-penalised multivariable logistic regression were performed to identify factors associated with severe postoperative complications (Clavien-Dindo grades III-IV). Left-sided colon cancer frequently presented at advanced stages or with complicated forms, with severe postoperative morbidity occurring in 9.0% of patients. Anastomotic leakage occurred in 8 of 153 patients with anastomoses (5.2%), with an associated overall mortality of 1.3%. In our cohort, lower preoperative haemoglobin levels, lower early postoperative albumin and total protein values, larger tumours, and synchronous colorectal tumours were associated with higher odds of severe postoperative complications. Our findings provide additional evidence on the incompletely characterised morbidity following left-sided colon cancer surgery.