IMA-origin Lymph Node Metastasis in Left Colon Cancer

ABSTRACT

PURPOSE: Although an extended colon resection with high ligation of the inferior mesenteric artery (IMA) generally has been recommended as curative surgery for advanced left colon cancer (LCC), it shows little or no survival advantage over segmental resection with low ligation of IMA. The present study is to determine the risk factors associated with IMA-origin lymph-node (LN) metastasis and to clarify the implication of IMA-origin LN metastasis. METHODS: We examined the clinicopathological results of 200 cases of LCC. LN dissection was performed as follows D2 en-bloc resection of the primary tumor, IMA-origin LN dissection, and paraaortic LN dissection. RESULTS: The incidence of IMA-origin LN metastasis of LCC was 4.5% (9 cases), and all cases involved sigmoid colon cancer. The independent risk factors of IMA-origin LN metastasis were four or more regional LN metastases (hazard ratio 16.51, 95% confidence interval 1.60~164.12) and a preoperative CEA level of greater than 6 ng/ml of (hazards ratio 6.63, 95% confidence interval 1.06~41.32). The incidence of IMA-origin LN metastasis among stage IIIC patients was 26.7%. Five of the 9 (55.6%) cases of IMA-origin LN metastasis had a concomitant paraaortic LN metastasis. CONCLUSIONS: The incidence of IMA-origin LN metastasis among patients with LCC was low; however, IMA-origin LN metastasis should be considered as a systemic metastasis.