A Population-Based Study of Complications After Colorectal Surgery in Patients Who Have Received Bevacizumab.

Background: Patients receiving Bevacizumab, a vascular endothelial growth factor inhibitor used to treat metastatic colorectal cancer, may be at greater risk of complications after colorectal surgery because of impaired healing.

Objective: The purpose of this study was to describe population-based rates of complications of colorectal surgery after Bevacizumab treatment and evaluate the relationship between time since last treatment and risk of complications.

Design: This was a population-based retrospective cohort study using administrative and cancer registry data.

Settings: The study was conducted in Ontario, Canada.

Patients: Patients with metastatic colorectal cancer receiving Bevacizumab between January 2008 and December 2011 were followed for a year after treatment or until death.

Main Outcome Measures: Administrative data were used to identify patients who underwent colorectal surgery after initiation of Bevacizumab and to determine whether they experienced a complicated postoperative course. The relationship between time since last Bevacizumab treatment (≤28 d, 29 d to 3 mo, and >3 mo) and risk of postoperative complications was evaluated using logistic regression.

Results: Of the 2759 patients who received Bevacizumab for the treatment of metastatic colorectal cancer, 265 underwent a colorectal procedure after exposure. The majority had a bowel resection or repair with no stoma (47.5%) and had emergency surgery (61.1%). Overall, 96 (36.2%) had a complicated postoperative course, including 20.4% readmission, 12.5% wound complications, and 7.9% mortality rate within 30 days of surgery. Adjusted multivariate analysis showed no difference in the likelihood of a complicated postoperative course among patients undergoing surgery within 28 days of receiving their last Bevacizumab dose compared with 29 days to 3 months (OR = 1.23 (95% CI, 0.53-2.84), or 3 to 12 months (OR = 0.98 (95% CI, 0.46-2.09) after receiving Bevacizumab.

Limitations: Reliance on administrative data to measure complications limited the scope of this study.

Conclusions: Patients with metastatic colorectal cancer requiring colorectal surgery after exposure to Bevacizumab experience substantial morbidity and mortality. The risk of complications is not detectably associated with time since exposure. See Video Abstract at http://links.lww.com/DCR/A474.