PURPOSE: This study was designed to examine the effect of neoadjuvant chemoradiation on pelvic sepsis after mesorectal excision for rectal cancer. METHODS: A retrospective chart review was conducted for all patients who underwent curative mesorectal excision for rectal cancer during an eight-year period. Demographic, preoperative, perioperative data were collected. Pelvic sepsis was defined as clinical or radiographically demonstrable leak or a pelvic abscess. Neoadjuvant chemoradiation included 5,040 Gy in conjunction with three cycles of 5-fluorouracil-based chemotherapy, followed by a one-month waiting period. RESULTS: From January 1994 to December 2002, 246 patients (151 males; mean age 68 (range, 36-97) years) underwent curative resection for rectal cancer. Procedures included 186 anterior resections, 52 abdominoperineal resections, and 8 Hartmann’s. Of 60 patients (24.4 percent) who had neoadjuvant chemoradiation, 9 (15 percent) developed pelvic sepsis (3 leaks, 6 abscesses) compared with 9 of 186 (4.8 percent) after primary surgery (6 leaks, 3 abscesses; P < 0.01). Ninety-three patients had an anastomosis ≤6 cm from the anal verge. Of these, 9 patients (9.7 percent) developed pelvic sepsis (5 leaks, 4 abscesses): 5 of 28 (17.9 percent) after neoadjuvant chemoradiation vs. 4 of 65 (6.2 percent) after primary surgery (P = 0.22). Only 6 of 93 patients (6.5 percent) with an anastomosis ≥7 cm developed pelvic sepsis (5 leaks and 1 abscess), of whom 1 had preoperative radiation. Pelvic abscess developed in 3 of 24 patients after neoadjuvant chemotherapy and abdominoperineal resection. After primary abdominoperineal resection, none of the remaining 28 patients developed pelvic sepsis. A multivariable logistic regression model was constructed to determine predictors of sepsis. Neoadjuvant chemotherapy was the only variable that was predictive (odds ratio, 3.4; 95 percent confidence interval, 1.3-9). CONCLUSIONS: The addition of neoadjuvant chemoradiation to mesorectal excision significantly increased the rate of pelvic sepsis. This was particularly true for anastomoses in the lower third of the rectum. Fecal diversion should be considered in these patients. PURPOSE: This study was designed to examine the effect of neoadjuvant chemoradiation on pelvic sepsis after mesorectal excision for rectal cancer. METHODS: A retrospective chart review was conducted for all patients who underwent curative mesorectal excision for rectal cancer during an eight-year period. Demographic , preoperative, perioperative data were collected. Pelvic sepsis was defined as clinical or radiographically demonstrable leak or a pelvic abscess. Neoadjuvant chemoradiation included 5,040 Gy in conjunction with three cycles of 5-fluorouracil-based chemotherapy, followed by a one-month waiting period. RESULTS: From January 1994 to December 2002, 246 patients (151 males; mean age 68 (range, 36-97) years) underwent curative resection for rectal cancer. Procedures included 186 anterior resections, 52 abdominoperineal resections, and 8 Hartmann’s. Of 60 (24.4 percent) who had neoadjuvant chemoradiation, 9 (15 percent) developed pelvic sepsis (3 leaks, 6 abscesses) comp Ninety-three patients had an anastomosis ≤6 cm from the anal verge. Of these, 9 patients (9.7 percent) developed pelvic Only 6 of 93 patients (6.5 percent) with an anastomosis ≥ 5 of 28 (17.9 percent) after neoadjuvant chemoradiation vs. 4 of 65 (6.2 percent) after primary surgery (P = 0.22) 7 cm developed pelvic sepsis (5 leaks and 1 abscess), of whom 1 had preoperative radiation. Pelvic abscess developed in 3 of 24 patients after neoadjuvant chemotherapy and abdominoperineal resection. After primary abdominoperineal resection, none of the remaining 28 patients developed pelvic sepsis. A multivariable logistic regression model was constructed to determine predictors of sepsis. Neoadjuvant chemotherapy was the only variable that was predictive (odds ratio, 3.4; 95 percent confidence interval, 1.3-9). CONCLUSIONS: The addition of neoadjuvant chemoradiation to mesor ectal excision significantly increased the rate of pelvic sepsis. This was particularly true for anastomoses in the lower third of the rectum. Fecal diversion should be considered in these patients.