Comparison between the Japanese general rules and the TNM system in the regional lymph node classification of carcinoma of the colon.

BACKGROUND

Metastasis to regional lymph nodes from carcinoma of the colon is an important prognostic factor. In the tumor, node, metastasis classification, node metastases are classified into four grades based on the number and distribution of metastatic nodes. In the Japanese General Rules for Clinical and Pathological Studies on Cancers of the Colon, Rectum and Anus, node metastases are classified into four grades based solely on the distribution of metastatic nodes.

STUDY DESIGN

Based on the findings of node metastases in 152 patients with carcinoma of the colon obtained by the clearing method, the node classifications by the Japanese General Rules and tumor, node, metastasis classifications were compared.

RESULTS

The case distribution by the Japanese General Rules grading was 38.2 percent in n(-), 30.3 percent in n1(+), 19.7 percent in n2(+), and 11.8 percent in n3(+) disease. In the tumor, node, metastasis classification, the distribution was 22.4 percent in pN1 and pN3 and 17.1 percent in pN2 disease. The five-year survival rate by the Japanese General Rules was 97.9 percent in n(-), 72.6 percent in n1(+), 51.2 percent in n2(+), and 30.0 percent in n3(+) disease, whereas in tumor, node, metastasis classification, this rate was 79.4 percent in pN1, 45.2 percent in pN2, and 44.8 percent in pN3 disease.

CONCLUSIONS

In the classification of regional node metastases from carcinoma of the colon, the Japanese General Rules showed a wider range in distribution and 5-year survival rate compared with the tumor, node, metastasis system.