Prognosis of Inferior Mesenteric and Para-aortic Lymph Node Metastases in Rectal Cancer: A Multicenter Study.

ABSTRACT

BACKGROUND/AIM: In colorectal cancer cases, treatment strategies differ between those with regional and extra-regional lymph node metastases. The inferior mesenteric lymph nodes are categorized as regional lymph nodes, while the para-aortic lymph nodes are classified as extra-regional lymph nodes. Although inferior mesenteric and para-aortic lymph node metastases are both associated with a dismal prognosis, few prognostic comparisons have been conducted. The present study aimed to clarify the prognosis of inferior mesenteric and para-aortic lymph node metastases in rectal cancer. PATIENTS AND METHODS: We retrospectively evaluated 71 patients with pathologically diagnosed rectosigmoid or rectal cancer with inferior mesenteric lymph node metastasis and 27 with pathologically diagnosed rectosigmoid or rectal cancer with para-aortic lymph node metastasis who underwent curative surgery. They were identified from the Japanese Study Group for Postoperative Follow-Up of Colorectal Cancer database. Overall survival, recurrence-free survival, and recurrence patterns were compared between the two groups. RESULTS: The five-year recurrence-free survival rates of patients with inferior mesenteric and para-aortic lymph node metastases were 31.2 and 28.1%, respectively (p=0.37), and the five-year overall survival rates were 43.1 and 39.6%, respectively (p=0.60). Furthermore, the survival curves of the two groups almost overlapped for both recurrence-free survival and overall survival rates. Recurrence patterns did not significantly differ between the two groups. CONCLUSION: In rectal cancer, the prognosis of inferior mesenteric lymph node metastasis is similar to that of para-aortic lymph node metastasis. Inferior mesenteric lymph node metastasis has a poor prognostic impact on rectal cancer.