Lymph node metastasis patterns in right-sided colon cancers: Is segmental resection of these tumors oncologically safe?

Purpose: The type of surgery and the extent of lymphadenectomy depend on the tumor location and should be based on the extent of lymphatic spread and the oncologic outcome. The aim was to analyze patterns of lymph node metastasis in patients with right-sided colon cancer. Methods: Between 1996 and 2007, a total of 419 patients underwent curative resection for right-sided colon cancer. Lymph nodes were grouped immediately after surgery on the basis of the location of the tumor. Results: There were 75, 208, 78, and 58 tumors in the cecum, ascending colon, at the hepatic flexure, and in the transverse colon, respectively. Of the 58 patients with transverse colon tumors, 43, 11, 3, and 1 underwent right hemicolectomies, transverse colectomies, left hemicolectomies, and a subtotal colectomy, respectively. Patients with cecal and ascending colon cancers most frequently had metastases in the ileocolic lymph nodes. Metastasis to the lymph nodes along the right branch of the middle colic artery occurred in 6.1% of patients with cecal cancer. In patients with hepatic flexure cancers, the epicolic lymph nodes along the right and middle colic arteries were most commonly metastatic lymph nodes. In transverse colon cancer, the middle colic node was the most commonly involved lymph node. Approximately 10% of patients had metastases to the right colic nodes. Conclusions: Metastasis to lymph nodes along the right colic artery occurred in approximately 10% of the patients with transverse cancer, indicating the need for great care in deciding the extent of segmental resection for these patients.