Is gastric carcinoma different between Japan and the United States?

Analyses of surgical results for gastric carcinoma often lead to the conclusion that gastric carcinoma occurring in Japan is different from that diagnosed in the U.S.

To elucidate factors that might explain the differences in surgical results between the two countries, the authors compared data from a cancer center and a university hospital in Japan and a specialist cancer hospital in the U.S (Memorial Sloan-Kettering Cancer Center [MSKCC]).

The mean age and body mass index were significantly greater in patients in the U.S. The N category appeared to be determined less accurately at MSKCC compared with the Japanese centers. The occurrence of early gastric carcinoma was not confined to Japanese patients because 20% of U.S. patients who underwent surgery were determined to have early stage disease. However, mucosal (in situ) carcinoma was detected rarely, and the proportion of advanced stage disease was greater in the U.S. Lesions in the upper gastric body, including the gastroesophageal junction, occurred in > 50% of cases at MSKCC but in only 20% of cases at the Japanese centers (P < 0.001). D2 lymph node dissection was possible with low morbidity and minimum mortality (31% and 3%, respectively, at MSKCC). The 5-year survival rates, stratified by tumor location and T category, revealed more similar results between Japan and the U.S. than had been reported previously. The marked difference between Japanese and American institutions only was observed for T1 and T2 tumors occurring in the lower gastric body and for T3 tumors occurring in the middle and upper third of the stomach.

Based on the findings of the current study, it would appear that the more favorable outcome noted for gastric carcinoma patients in Japan primarily is explained by the differences in tumor location, a greater frequency of early stage disease, and more accurate staging compared with gastric carcinoma patients in the U.S. Results of gastric carcinoma treatment comparable to those obtained in Japan can be obtained in Western centers.