The difference in gastric cancer between Japan, USA and Europe: what are the facts? what are the suggestions?

ABSTRACT

In Japan the survival rate for gastric cancer has steadily improved over the last 30 years whilst that in the West has remained static and inferior. In this review three hypotheses are examined to explain the difference. There is little evidence to suggest genetic differences, which might result in a less aggressive cancer in Japan. Recently there has been a rise in the proportion of cancers of the gastro-oesophageal junction in the West and this has not been seen in Japan. The comparison of survival data from these two regions is problematic with different staging systems and a stage migration effect. The established surgical treatment of gastric cancer in Japan is radical gastrectomy and regional lymphadenectomy and this has been proposed as a superior treatment to the standard gastrectomy common in the West. The results for survival benefit however, have not been reproduced in randomized clinical trials. The heterogeneity of adjuvant and neoadjuvant treatment regimens in Japan and the West has led to difficulties in the interpretation of their effects. There is considerable scope for future collaboration between clinicians in the West and Japan.