Clinical Analysis for Lymph Node Metastasis as a Guide to Modified Surgery for Early Gastric Cancer

ABSTRACT

The authors have analyzed the clinicopathologic data of 855 patients with early gastric cancer (EGC) who underwent D2 lymph node dissection during the 7-year period between January 1990 and December 1996 in order to evaluate the factors influencing lymph node metastasis and to establish the clinical indications and guidelines for modified surgery in EGC patients. The overall rate of lymph node metastasis was 13.5% (115/855). There was a significant statistical difference for lymph node metastasis between men (67/575, 11.7%) and women (48/280, 17.1%)(p<0.05). In mucosal cancer, the rate of lymph node metastasis was 4.7% (20/427), and in submucosal cancer, it was 22.2% (95/428), which is a significant difference between the two groups. There was also a significant difference for lymph node metastasis between the elevated types (EGC type I and IIa) and the depressed types (type IIb, IIc, and III), 8.4% (13/154) and 14.6% (102/701), respectively (p=0.05). There were only one lymph node positive case (1/82, 1.2%) among the elevated mucosal cancers. Smaller tumors((10 mm) showed a significantly lower incidence of lymph node metastasis than larger tumors (11 mm)(p<0.01); 4 cases invoving tumors of less than 11 mm had lymph node metastasis(2 mucosal and 2 submucosal lesions). Differentiated mucosal carcinomas showed a significantly lower incidence of lymph node metastasis than undifferentiated carcinomas (0.9% vs 8.5%, p<0.001), whereas there was no significant difference between differentiated and undifferentiated submucosal cancers. There were 14 cases of EGC with metastasis in the secondary lymph node group (N2) consisting of 5 men and 9 women, with a mean age of 53 years. Among them, the 7 cases under the age of 50 were all female patients. For thses 14 case, the average tumor size was 34 mm (15~90 mm), and the majority of were depressed types (11 cases) and undifferentiated type (12 cases). These results suggest that modified surgery is indicated as an optimal treatment option for mucosal cancer with elevated and/or differentiated type tumors, on the basis of not only radicality but also postoperative quality of life.