Incidence

Incidence

There are marked variations in the incidence of gastric cancer worldwide. In the UK, it is approximately 15 per 100 /uni00A0 000 per year; in the USA, 10 per 100 /uni00A0 000 per year; and in Eastern Europe, 40 per 100 /uni00A0 000 per year. In Japan, the disease is much more common, with an incidence of approximately 70 per 100 /uni00A0 000 per year. There are areas in China where the incidence even higher. These underlying epidemiological data make it clear that this is an environmental disease. In general, men are more a ff ected by the disease than women and, as with most solid organ malignancies, the incidence increases with age. in terms of the incidence and site of gastric cancer and the pop ulation a ff ected, changes that to date have not been observed in Japan. First, the incidence of gastric cancer is continuing to fall at about 1% per year. This reduction exclusiv ely a ff ects carcinoma arising in the body and distal stomach. In contrast, there appears to be an increase in the incidence of carcinoma in the proximal stomach, particularly the GOJ. Carcinoma of the distal stomach and body of the stomach is most common in low socioeconomic groups, whereas the increase in proximal gastric cancer seems to a ff ect principally higher socioeconomic groups. Proximal gastric cancer does not seem to be associated with H. pylori infection, in contrast with carcinoma of the body and distal stomach.