Cancer in Africa, Especially in Regions South of the Sahara2

Abstract

Striking differences are noted in cancer incidence, situation, and histopathological type between and within races of Africa. These suggest that 80 percent or more of the cancers affecting western races are environmentally induced and potentially preventable. Negriform races generally have a much lower incidence than western races or U.S. non-whites, which disposes of the hypothesis of the uniform liability of mankind to cancer. The gradual assumption of a western manner of life by African races has resulted in the availability for study of material from these vast human experiments. Among the Negriform races, cancers of stomach, large bowel, breast, endometrium, ovary, brain, and leukemia are generally rare. Common to them are primary cancer of the liver, Kaposi's sarcoma, Burkitt's tumor, and, in some regions, esophageal cancer. The mixed race (Colored) has a high rate of stomach and liver cancer. Asians have a lower mortality. South African whites resemble U.S. whites, except for higher rates for lip, tongue, stomach, prostate, skin, and bone cancers. Etiological aspects of individual tumors are discussed with regard to lip (tobacco and sunlight), mouth, postnasal space, esophagus, liver (fungal toxins?), sinuses (snuff), lung (smoking, arsenic), mesothelium (asbestos), uterus, penis (circumcision, ablution), bladder (bilharziasis), prostate, skin (sunlight, tropical ulceration, other ulcers), eye, conjunctiva (sunlight), brain, and lymphomas. Since most cases of cancer in Africa are out of reach of methods of treatment other than chemotherapy, great need as well as opportunities exist for the study of carcinostatics.