Abstract
The gastric cancer incidence in Semarang, Indonesia, is exceedingly low: only approximately 1/100th of the level in Japan. To elucidate the reason, we carried out an ecological study recruiting 69 male and 102 female participants from the general populace in January 2005. Positive urea breath tests were 0% for both men and women, and Helicobacter pylori (H. pylori) IgG antibodies were found in 2% (0-5, 95% confidence interval) of men and 2% (0-4) of women, significantly lower than the 62% (58-65) and 57% (53-60), respectively, in Japan. Furthermore, there were no positive findings with the pepsinogen tests in Semarang, again significant in comparison with the 23% (22-25) and 22% (20-23) in Japan. Variation in smoking levels and consumption of NaCl, vegetables and fruit were found, but not to an extent that would allow explanation of the major differences in gastric cancer incidence. We may conclude that the very low prevalence of H. pylori infection and thus chronic atrophic gastritis account for the rarity of stomach cancer in Semarang, Indonesia.