Purpose: Neoadjuvant chemoradiotherapy for rectal cancer is associated with improved local control and may result in complete tumor response. Associations between tumor response and disease control following radical resection should be established before tumor response is used to evaluate treatment strategies. The purpose of this study was to assess and compare oncologic outcomes associated with the degree of pathologic response after chemoradiotherapy. Patients and Methods: All patients with locally advanced (cT3-4 or cN+ by endorectal ultrasonography, computed tomography, or magnetic resonance imaging) rectal carcinoma diagnosed from 1993 to 2008 at our institution and treated with preoperative chemoradiotherapy and radical resection were identified, and their records were retrospectively reviewed. The median radiation dose was 50.4 Gy with concurrent chemotherapy. Recurrence-free survival (RFS), distant metastasis (DM), and local recurrence (LR) rates were compared among patients with complete (ypT0N0), intermediate (ypT1-2N0), or poor (ypT3-4 or N+) response by using Kaplan-Meier survival analysis and multivariate Cox proportional hazards regression. Results: In all, 725 patients were classified by tumor response: complete (131; 18.1%), intermediate (210; 29.0%), and poor (384; 53.0%). Age, sex, cN stage, and tumor location were not related to tumor response. Tumor response (complete v intermediate v poor) was associated with 5-year RFS (90.5% v 78.7% v 58.5%; P < .001), 5-year DM rates (7.0% v 10.1% v 26.5%; P < .001), and 5-year LR only rates (0% v 1.4% v 4.4%; P = .002). Conclusion: Treatment response to neoadjuvant chemoradiotherapy among patients with locally advanced rectal cancer undergoing radical resection is an early surrogate marker and correlate to oncologic outcomes. These data provide guidance with response-stratified oncologic benchmarks for comparisons of novel treatment strategies.

The impact of anastomotic leakage on the long-term oncologic outcome is not clear. This retrospective study evaluated risk factors and oncologic impacts of anastomotic leakage after rectal cancer surgery. Data were analyzed from 1,391 patients who underwent sphincter preservation for rectal cancer between January 1997 and August 2003. Operations were classified as anterior resection (n = 164), low anterior resection (n = 898), or ultralow anterior resection (n = 329). The anastomotic leakage rate was 2.5 percent. Multivariate analysis identified male (hazard ratio, 3.03), old age (hazard ratio, 2.42), and lower anastomosis level (hazard ratio, 2.68) as risk factors for leakage. The local recurrence rates were 9.6 and 2.2 percent for the leakage and nonleakage groups, respectively but were not significant (P = 0.14). The overall five-year survival rates were 55.1 and 74.1 percent in the leakage and nonleakage groups, respectively (P < 0.05), and the cancer-specific survival rates were 63 and 78.3 percent in the leakage and nonleakage groups, respectively (P = 0.05). However, in subgroup analysis, significant differences were identified only in Stage III patients. Age, sex, and ultralow anterior resection were found to be risk factors for anastomotic leakage after rectal cancer surgery. In addition, leakage was associated with poor survival.