Purpose: The prognostic significance of apical-node metastasis around the inferior mesenteric artery (IMA) remains unclear. We investigated the oncological relevance of apical-node metastasis detected after high ligation of the IMA in stage III sigmoid colon or rectal cancer.
Methods: Between May 2003 and December 2007, 229 consecutive patients with stage III sigmoid colon or rectal cancer, who had undergone curative resection with high ligation, were analyzed. Cox proportional regression model was used to identify the prognostic factors for disease-free survival.
Results: Thirty-one patients (13.5%) had apical-node metastases: 0% with T0-1, 3.8% with T2, 11.5% with T3, and 29.3% with T4 disease (p = 0.017). Additionally, the factors related to apical-node metastasis were tumor size, number of metastatic lymph nodes, lymph-node ratio, and N-stage. Multivariate analysis showed that the lymph-node ratio (odds ratio (OR) = 40.53, 95% confidence interval (CI) = 8.41-195.22, p < 0.001) was an independent prognostic factor for disease-free survival but that apical-node metastasis was not a factor that predicted a poor outcome (OR = 1.53, 95% CI = 0.81-2.91, p = 0.192). Apical-node metastasis was not a prognostic factor for disease-free survival on multivariate analysis of the subgroups based on tumor location (sigmoid colon cancer: OR = 1.42, 95% CI = 0.42-1.82, p = 0.577; rectal cancer: OR = 1.82, 95% CI = 0.82-4.06, p = 0.141).
Conclusions: This study suggests that apical-node metastasis is not a poor prognostic factor for stage III sigmoid colon or rectal cancer after high ligation.