Influence of Neoadjuvant Radiotherapy on Anastomotic Leak After Restorative Resection for Rectal Cancer

This study was undertaken to determine whether neoadjuvant radiotherapy is associated with an increased risk of anastomotic leak for rectal cancer patients undergoing restorative resection. From 1980 to 2010, patients who underwent restorative resection for rectal cancer (tumors within 15 cm of anal verge) were identified from a prospective institutional database and grouped based on whether they received neoadjuvant radiotherapy (+RT) or not (-RT). The main outcome was anastomotic leak documented by imaging (contrast leak), intra-operative or clinical (signs of peritonitis) findings and confirmed by staff surgeon assessment. Using multivariate (MV) analysis risk factors for leak were identified, presented as OR (95 % CI). One thousand eight hundred sixty-two patients were included in the analysis, 28 % in the +RT group. Eighty-six percent of +RT patients received neoadjuvant chemoradiotherapy. The overall leak rate was 6.3 %, with no significant difference in +RT and -RT groups (8 % vs 5.7 %, p = 0.06). The +RT group had a lower mean age at surgery (58 vs 63 year, p < 0.001), more male (75 % vs 62 %, p < 0.001) and more ASA 3/4 (44 % vs 35 %, p < 0.001) patients, greater use of defunctioning ostomy (87 % vs 44 %, p < 0.001) and colo-anal anastomosis (77 % vs 34 %, p < 0.001). Mean tumor distance from the anal verge was lower in +RT group (6.6 vs 9.7 cm, p < 0.001). On MV analysis, male sex (OR 1.64 (1.03-2.62), p = 0.038), ASA 4 (OR 4.70 (2.07-10.7), p < 0.001), tumor distance from anal verge a parts per thousand currency signaEuro parts per thousand 5 cm (OR 2.49 (1.37-4.52), p = 0.003), and tumor size at surgery a parts per thousand yenaEuro parts per thousand 4 cm (OR 1.75 (1.15-2.65), p = 0.009) were independently associated with leak. +RT was not independently associated with leak (OR 1.44 (0.85-2.46), p = 0.18), while defunctioning ostomy did not reduce leak occurrence (OR 0.75 (0.44-1.28), p = 0.29). The findings suggest that neoadjuvant radiotherapy is not independently associated with an anastomotic leak for rectal cancer patients undergoing restorative resection and support a selective policy towards the use of a defunctioning ostomy on a case by case basis based on intra-operative judgment and consideration of tumor location, size, and patient characteristics.