Is the new UICC staging system of gastric cancer reasonable? (Comparison of 5-year survival rate of gastric cancer by old and new UICC stage classification)

Abstract

In the new UICC TNM system for gastric cancer approved in 1985, a T1 lesion with lymph node (LN) metastasis is classified as stage, Ib; in the old TNM system this was classified as stage III. This is contradictory to a general rule of the UICC TNM system, whereby cancer with LN metastasis is classified as stage II or III. Two thousand and sixty-three patients with less than T4 gastric cancer who were treated at Seoul National University Hospital from 1970 to 1986 were analysed for significant prognostic factors. Survival curves were subsequently analysed according to the number of LN metastases and the depth of invasion. As a result of multivariate study for clinical and pathological features such as age, tumour location, gross appearance, histological type, depth of tumour invasion and regional lymph node metastasis, we confirmed that only two factors — regional lymph node metastasis and depth of gastric wall invasion — are significant. We showed that when the LN variable is classified according to the number of LN metastases (0 group, 1–3 group, > 3 group) like the UICC TNM classification of colorectal cancer, the survival curves are similar to those reported by the Japanese Research Society for Gastric Cancer. The authors propose the modification of the UICC TNM classification system according to depth of invasion and the number of LN metastases, whereby a T1 lesion with LN metastasis is classsified as stage IIa instead of stage 1b.