Epidemiology of intestinal and diffuse types of gastric carcinoma in the Mount Kilimanjaro area, Tanzania.

Carcinoma of the stomach is the commonest malignancy in the Mount Kilimanjaro area of Tanzania, with relative frequencies of 16.3 and 15.1% of all malignancies for males and females, respectively; and even considerably higher population based incidences than in other African registries. In this area with high risk for gastric carcinoma the ratio of intestinal to diffuse type (I:D) was significantly higher, 4.1 compared with 2.1 in the other, lower risk, regions of Northern Tanzania. Tumours of intestinal type were more often seen in young patients around Mount Kilimanjaro than in other countries, 6.0% of the patients with an I:D of 3.7 being under 35 years of age. Likewise, the proportion of females with gastric carcinoma was higher in the Mount Kilimanjaro area with an I:D ratio of 3.1, compared with 1.7 in females from the other regions. The high frequency of stomach cancer in the Mount Kilimanjaro area may be due to the influence of volcanic soils.