New Classification of Lymph Node Metastasis Grading in Dukes C Colon and Rectosigmoid Cancer Based on Metastatic Rate and Prognosis

Abstract

We studied whether the lymph node metastasis rate indicates the lymph node metastasis grade in 149 subjects with Dukes C colon and rectosigmoid cancer undergoing curative surgery. We alse analyzed the relationship between the metatstasis rate and survival. When the cases were classified into the metastasis rate of less than 20% and those of 20% or more, the survival difference was significant. When the cases were classified into 4 groups by the metastasis rate (less than 20% / 20% or more) and pN1 / pN2 or pN3, survival in those with a metastasis rate of <20% and pN1 was significantly better than others. Multivariate analysis showed that the lymph node metastasis grade was an independent prognostic factor regardless of whether the Japanese classification or metastasis rate was used as the metastasis grade. Using the lymph node metastasis grade together with the metastasis rate enables prognosis to be predicted in lymph node metastasis.