Neoadjuvant chemoradiotherapy for rectal carcinoma: effects on anastomotic leak rate and postoperative bladder dysfunction after non-emergency sphincter-preserving anterior rectal resection. Results of the Quality Assurance in Rectal Cancer Surgery multicenter observational trial.

INTRODUCTION: Randomized trials have demonstrated a reduction in local recurrence rate in rectal cancer patients treated with preoperative chemoradiotherapy and total mesorectal excision (TME) compared to patients undergoing TME alone. Accordingly, preoperative chemoradiotherapy in all UICC stages II and III rectal cancers has been recommended in the German treatment guidelines as of 2004. However, this policy has been questioned in recent years, partly due to concern regarding an increase in postoperative complications through preoperative therapy. Studies on this issue are sparse; most have been conducted in specialized centers, included relatively few patients, and yielded partly contradicting results. It was the aim of our analysis to investigate the influence of preoperative chemoradiotherapy on anastomotic leak rate and postoperative bladder dysfunction in rectal cancer patients using a representative data set from the Quality Assurance in Rectal Cancer Surgery multicenter observational trial.

METHOD: This is a retrospective analysis of data from the Quality Assurance in Rectal Cancer Surgery prospective multicenter observational trial. Data of all patients undergoing curatively intended sphincter-preserving resection for UICC stage I through III rectal carcinoma between 01 Jan 2005 and 31 Dec 2007 with or without preoperative chemoradiotherapy (groups A and B, respectively) were included. Multivariate statistical analysis using propensity score analysis was carried out regarding outcome parameters total anastomotic leak rate, rate of anastomotic leaks requiring reoperation, and postoperative bladder dysfunction.

RESULTS: A total of 2,085 patients were included (group A, n = 676, group B, n = 1,409). Significant differences were present between groups regarding age, sex, distance of the tumor from the anal verge, pT-stage, UICC stage, hepatic risk factors, and use of protective enterostomy by univariate analysis. Multivariate logistic regression including these parameters was used to calculate the propensity score (likelihood to be assigned to group A or B as a consequence of the individual profile of these factors) for each patient. When outcome parameters were compared between groups A and B after stratification for propensity score, no significant differences regarding postoperative bladder dysfunction (p = 0.12), total anastomotic leak rate (p = 0.56), and anastomotic leaks requiring reoperation (p = 0.56) could be demonstrated.

CONCLUSION: Neoadjuvant chemoradiotherapy for rectal carcinoma does not increase the risk for anastomotic leakage or postoperative bladder dysfunction after curatively intended sphincter-preserving rectal resection.