Cancer patterns in three African populations compared with the United States black population.

Cancer incidence rates and patterns in three African populations in the Gambia, Mali and South Africa, have been compared with corresponding data on the Black population in Connecticut, USA. In the African populations, total rates for cancer are much lower than that of US Blacks, even allowing for under-reporting. Chief cancers are those of the oesophagus, liver and cervix. In Mali, stomach cancer is very common. As to trends, among South African Blacks, a population in transition, rates are rising, albeit slowly, of cancers of prosperity--prostate, lung, breast and colon-rectum. Salient questions are: can the number of cancers of underprivilege be lessened, and can cancers linked with rising socioeconomic states be restrained? Discussions of common risk factors, including diet, reproduction, smoking and drinking practices, indicate that for Africans as a whole, continuing poverty will prevent major changes in cancer pattern and rises in occurrence of the disease. However, should prosperity increase for Africans in big cities, rates are ultimately likely to attain those prevailing in the US Black population. Significant avoiding action seems almost impossible.