Clinical Significance of Lateral Lymph Node Dissection for Stage Ⅳ Low Rectal Cancer

We reviewed the clinical records of 81 patients with stage Ⅳ low rectal carcinoma (LRC) (25 Cur B surgeries and 56 Cur C surgeries) to evaluate the effectiveness of lateral lymph node dissection (LLND) by comparing the treatment outcomes with those of patients with stage Ⅲ LRC. Mesenteric lymph node metastasis was a risk factor for local recurrence in a multivariate analysis. There were no significant differences in the frequency of lateral node metastasis, local recurrence rate, or prognosis between Cur B and stage Ⅲ LRC patients. We suggest that LLND effectively improves prognosis as well as local control in Cur B patients. In Cur C patients, prognosis was poor regardless of lateral node metastasis. However, in patients with lateral node metastasis, there were no significant differences in between the Cur C (25.0%), Cur B, and stage Ⅲ groups, suggesting that LLND improves local control in Cur C patients with lateral node metastasis. Although the local recurrence rate was high (71.4%) in Cur C patients without lateral node metastasis, fewer lateral lymph nodes were harvested in these patients than in those with lateral node metastasis. Our results indicate that further examination of the local control effects of LLND in Cur C patients is necessary.