Preoperative chemoradiotherapy effects on anastomotic leakage after rectal cancer resection: a propensity score matching analysis.

OBJECTIVE: To assess the effects of preoperative chemoradiotherapy (CRT) on anastomotic leakage (AL) after rectal cancer resection, using propensity score matching.

BACKGROUND: Conflicting data have emerged over the last decade regarding the effect of preoperative CRT on AL.

METHODS: We reviewed 1437 consecutive patients with rectal cancer who underwent low anterior resection (LAR) at our institution between 2005 and 2012. AL evaluated as grade C was the primary endpoint, as proposed by the International Study Group of Rectal Cancer in 2010. The patients were treated with (n = 360) or without (n = 1077) preoperative CRT. The total radiation dose was 50.4 Gy in 28 fractions. Multivariate and propensity score matching analyses were used to compensate for the differences in some baseline characteristics.

RESULTS: The preoperative CRT group contained more patients with the following characteristics, older age, male sex, smoker, advanced stage tumor, lower/mid rectal tumor location, ultra-LAR, and diverting stoma, than the non-preoperative CRT group (all Ps < 0.05). Postoperative AL occurred in 91 patients (6.3%). Before propensity score matching, the incidence of AL in patients with or without preoperative CRT was 7.5% and 5.9%, respectively (P = 0.293). After propensity score matching, the 2 groups were nearly balanced except for the initial stage and the length of the surgeon's career, and the incidence of AL in patients with or without preoperative CRT was 7.5% and 8.1%, respectively (P = 0.781).

CONCLUSIONS: We did not observe that preoperative CRT increased the risk of postoperative AL after LAR in patients with rectal cancer, using propensity score matching analysis.