Gastric cancer in sub-Saharan Africa.

Gastric cancer has a variable but generally low prevalence in black populations of sub-Saharan Africa, despite a high prevalence of Helicobacter pylori (the 'African enigma'). Evidence from Soweto indicates that the host response to H. pylori may be protective against a virulent organism and that, in most people, H. pylori does not lead to more serious sequelae. This suggests that there may be host protective/inhibitory factors present, which prevent the progression of H. pylori-induced chronic active gastritis to cancer.