Is the prognosis for Japanese and German patients with gastric cancer really different?

Differing survival rates have been reported between patients having undergone surgical intervention for the treatment of gastric carcinoma in Japan and Western industrialized countries. Through the actual availability of the data compiled at a major Japanese medical center (National Cancer Center, Tokyo), it was possible, for the first time, to compare the patients and therapeutic results of a Japanese center (n = 1475) with that of a German center (Department of Surgery, Technical University of Munich, Munich; n = 453). The prognostic factors involving both groups were compared. Survival rates were analyzed in univariate and multivariate fashions. Some of the examined prognostic factors, such as sex, histologic type, tumor size, and Borrmann classification, were similarly distributed. Differences in frequency were discovered concerning pathologic tumor (pT), node (pN), and metastasis (pM) categories, localization, and age groups. Univariate analysis showed a 2-year survival rate of 88% for all Japanese patients with gastric cancer compared with 58% for German patients. The 5-year survival rates were 77% and 44%, respectively. The difference in the 2-year and 5-year survival rates for both departments may be related to differences in frequencies of several characteristics. In performing the same analysis in a multivariate fashion for the patient populations at both centers, it became clear that an important prognostic factor was the center itself. The survival curves of patients from Tokyo and Munich with the same prognostic factors demonstrate this difference. These differences, however, were small in comparison with those of univariate analysis. Using a similar classification of the tumor stage and similar prognostic characteristics, the prognosis for gastric cancer in Japan and Germany may be the same.