Apical node metastasis independently predicts poor survival in Dukes C colorectal cancer

Abstract

The prognostic significance of apical node metastasis in node-positive colorectal cancer (CRC) is disregarded by the Fourth American Joint Committee on Cancer and the International Union Against Cancer (AJCC/UICC) TNM classification system. The influence of apical node metastases on overall 5-year survival among patients with Dukes stage C CRC was examined. Patients who underwent operative resection for CRC between 1999 and 2003 were reviewed. Two-hundred and ninety patients were included in the study, including 203 with Dukes C apical node-negative cancers, 39 with Dukes C apical node-positive cancers and 48 with Dukes D cancers. The respective prevalence of extramural vascular invasion was 35%vs 64%vs 56% (P = 0.0005), T4-stage 24%vs 38%vs 48% (P = 0.013), positive resection margin 16%vs 41%vs 23% (P = 0.001), more than three positive nodes harvested 28%vs 85%vs 52% (P < 0.0001) and poorer tumour differentiation grade 9%vs 21%vs 23% (P = 0.009). Multivariate analyses of all Dukes C cancer patients (n = 242) showed a positive apical node to be a highly significant independent predictor of mortality (hazard ratio 2.281, 95% confidence interval 1.421-3.662, P = 0.0006). Extramural vascular invasion and a positive resection margin were also independent predictors of poor survival. Patients with Dukes C apical node-positive cancers had a significantly poorer overall 5-year survival compared to patients with Dukes C apical node-negative cancers (P < 0.0001) but survival was not significantly different compared to patients with distant metastases at initial presentation (P = 0.504). Apical node metastasis appears to be a strong independent, negative prognostic factor of poor survival in Dukes C CRC.