Classification of regional lymph node metastasis from gastric carcinoma

Abstract

Classification of lymph node metastasis from gastric carcinoma was based on the localization (International Union Against Cancer/American Joint Committee on Cancer [UICC/AJCC] 1992). The authors analyzed the data of the German Gastric Cancer Study (GGCS) to determine whether the number of involved lymph nodes related to the prognosis independent of their anatomic localization (UICC/AJCC 1997). For 477 patients of the GGCS resected for cure (UICC/AJCC R0 resection) who had involved regional lymph nodes and no evidence of distant metastases, the 1992 UICC/AJCC classification was compared with the new UICC/AJCC classification (1997) based on the number of involved lymph nodes (ILN). Two hundred fifty-eight patients (54.1%) had 1-6 ILN, 137 patients (28.7%) had 7-15, and 82 patients (17.2%) had more than 15. When the 1992 and 1997 UICC/AJCC classifications were compared, the prognosis of patients classified as pN1 (n = 187) in the 1992 pN classification was homogeneous, whereas there was a marked lack of homogeneity among the patients classified as pN2 (n = 290). For 103 of 290 patients with 1-6 ILN, the prognosis appeared to be more favorable (5-year survival rate, 45.5%), whereas 137 of 290 patients with 7-15 ILN had an intermediate prognosis (5-year survival rate, 29.7%). Eighty-two of 290 patients had a dismal prognosis, with a 5-year survival rate of 10.4%. There was a highly significant difference in survival (P < 0.0001). Within the groups with 1-6, 7-15, and more than 15 ILN, the localization of ILN did not significantly alter the prognosis. The UICC/AJCC classification based on the number of involved regional lymph nodes allows for an estimation of prognosis superior to the 1992 classification. In addition, the new classification can now be applied without methodologic problems and seems more reproducible.