Anastomotic Leakage and Interval between Preoperative Short-Course Radiotherapy and Operation for Rectal Cancer.

Background: Short-course preoperative radiotherapy is indicated in patients with resectable rectal cancer to control local recurrence. Although no clear evidence is available, short-course radiotherapy with operation within a week is common practice. The aim of this study was to investigate the impact of timing of operation for rectal cancer after short-course radiotherapy on anastomotic leakage.

Study Design: Data from the Dutch Colorectal Audit were used. All patients who received short-course preoperative radiotherapy and underwent elective operation within 14 days for rectal cancer between January 1, 2011 and December 31, 2016 were included. Interval between radiotherapy and operation was calculated by extracting date of start of radiotherapy from the date of operation. Patients were divided into short interval (<4 days) and long interval (4 or more days). The interval and other patient or perioperative parameters were included in univariable and multivariable logistic regression analyses to identify independent associations with anastomotic leakage.

Results: In total, 2,131 patients were eligible for analysis: 1,055 (49.5%) patients had operations <4 days after radiotherapy and 1,076 (50.5%) patients had operations after 4 or more days. One hundred and eighty-five (8.7%) patients experienced anastomotic leakage. The incidence of anastomotic leakage was significantly higher in patients who underwent operation within <4 days (10.1% vs 7.2%; p = 0.018). In the multivariable analysis, an interval of <4 days was significantly associated with anastomotic leakage (odds ratio 1.438; 95% CI 1.054 to 1.962; p = 0.022).

Conclusions: Elective surgery for rectal cancer <4 days after preoperative short-course radiotherapy resulted in an increase of anastomotic leakage.