Inferior Mesenteric Artery Lymph Node Metastasis Is an Independent Prognostic Factor for Stage III Sigmoid Colon and Rectal Cancer

Abstract

It is unclear whether the number or distribution of lymph node metastases can provide a more accurate prognosis. The aim of this study was to evaluate the prognostic impact of inferior mesenteric artery (IMA) lymph node metastasis (LNM) in sigmoid colon and rectal cancer. We included 188 patients who underwent curative resection for stage III sigmoid colon and rectal cancer between January 2001 and December 2012. Patients were divided into 2 groups based on the presence of IMA-LNM (LNM-positive versus LNM-negative group). Clinicopathologic characteristics, 3-year recurrence-free survival and 5-year overall survival rates, and recurrence patterns were compared between the 2 groups. Of 188 patients, 9 patients (4.79%) were in the LNM-positive group. After curative resection, 3-year recurrence-free survival and 5-year overall survival rates were significantly lower in the LNM-positive group compared to the LNM-negative group (44.44% versus 69.98%, P = 0.016 for 3-year recurrence-free survival and 48.61% versus 81.73%, P = 0.018 for 5-year overall survival). Multivariate analysis revealed that the presence of IMA-LNM (P = 0.04), not the number of LNMs (P = 0.153), was an independent prognostic factor for recurrence-free survival. The para-aortic LNM rate was significantly higher in the LNM-positive group (P = 0.0078). IMA-LNM is an independent predictor of survival for stage III sigmoid colon and rectal cancer patients. Evaluation of IMA-LNM enables accurate estimation of patient prognosis and enhances appropriate postoperative therapy.