Number of lymph node metastases is better predictor of prognosis than level of lymph node metastasis in patients with node-positive colon cancer.

Abstract

Lymph node metastasis is the most important prognostic factor for colon cancer patients. Survival is also related to the number and level of positive lymph nodes (PLNs). Definitions of degree of PLNs for colon cancer differ greatly between the number and level of PLNs. The aim of this study is to compare number and level of PLNs to see which is a better predictor of prognosis for node-positive colon cancer. One hundred eighteen patients underwent histologically curative resection for node-positive colon cancer. We calculated the cumulative 5-year survival rates and examined prognostic factors for multivariate analysis based on the number and level of PLNs and additional factors. The number of PLNs was classified as either one to three PLNs or more than four PLNs, and level of PLNs was classified as either Level I (pericolic lymph node metastasis) or Level II (lymph node metastasis along the major named vessel supplying the tumor, and that around the origin of a main artery). Cumulative 5-year survival rates were statistically different between the 1 to 3 PLNs group and the more than 4 PLNs group, but not significantly different between Level I group and Level II group. Multivariate analysis showed that number, not level, of PLNs was an independent prognostic factor. In node-positive colon cancer, number of PLNs predicted prognosis better than level of PLNs.