Role of the Interval from Completion of Neoadjuvant Therapy to Surgery in Postoperative Morbidity in Patients with Locally Advanced Rectal Cancer

Background: Increasing the interval from completion of neoadjuvant therapy to surgery beyond 8 weeks is associated with increased response of rectal cancer to neoadjuvant therapy. However, reports are conflicting on whether extending the time to surgery is associated with increased perioperative morbidity. Methods: Patients who presented with a tumor within 15 cm of the anal verge in 2009–2015 were grouped according to the interval between completion of neoadjuvant therapy and surgery: < 8 weeks, 8–12 weeks, and 12–16 weeks. Results: Among 607 patients, the surgery was performed at < 8 weeks in 317 patients, 8–12 weeks in 229 patients, and 12–16 weeks in 61 patients. Patients who underwent surgery at 8–12 weeks and patients who underwent surgery at < 8 weeks had comparable rates of complications (37% and 44%, respectively). Univariable analysis identified male sex, earlier date of diagnosis, tumor location within 5 cm of the anal verge, open operative approach, abdominoperineal resection, and use of neoadjuvant chemoradiotherapy alone to be associated with higher rates of complications. In multivariable analysis, male sex, tumor location within 5 cm of the anal verge, open operative approach, and neoadjuvant chemoradiotherapy administered alone were independently associated with the presence of a complication. The interval between neoadjuvant therapy and surgery was not an independent predictor of postoperative complications. Conclusions: Delaying surgery beyond 8 weeks from completion of neoadjuvant therapy does not appear to increase surgical morbidity in rectal cancer patients.