With recent changes in environmental factors among Africans in South Africa, how have cancer occurrences been affected?

Abstract

In South Africa, with changes in environmental factors, varyingly, there have been measures of westernization of diet, with slight rises in intakes of energy and fat, with more of animal, but less of plant foods, being eaten, and with a fall in dietary fibre intake. Smoking practice has increased, particularly in males, likewise alcohol consumption. Physical activity has fallen, especially in urban dwellers. Changes in cancer incidence rates, as reported in the South African Cancer Registry for the periods 1986 and 1993-1995 have been investigated. Additionally, changes in percentages of cancers in hospitals in Johannesburg during 1953-1955 and in Durban during 1994-1996, have been looked into. The high occurrences of oesophageal and cervix cancers have fallen slightly, although more so in respect of liver cancer. But there have been rises, widely varying, in the cases of cancers of the lung, prostate and breast. While some of these changes would be expected from the changes in environmental factors, many cancer occurrence situations remain problematical, e.g. the continuing low occurrence of colorectal cancer. Recently, the rapidly rising epidemic of HIV/AIDS has slightly increased the occurrence of certain cancers, particularly Kaposi’s sarcoma and non-Hodgkin’s lymphoma. Regarding prevention, chances of cancer control in Africans, through lessening personal risk factors, are very remote, which unfortunately also prevails in large measure in western populations, regarding their reluctance to make the recommended beneficial changes.