Epidemiological aspects of cervical cancer in tropical Africa.

Cervical cancer is one of the most common malignant tumours in tropical Africa accounting, for example, for nearly one-quarter of female cancer cases overall in Uganda. The disease is likely to be under-reported and available incidence rates are probably gross underestimates. Spread is through sexual contacts. Both female and male promiscuity and a low standard of sexual hygiene lead to a high incidence within a given community. A number of investigations show that the risk of cervical cancer varies little, whether or not the male partner has been circumcised, but these findings seem to indicate only that extreme cleanliness is more effective than circumcision alone. Populations of Uganda who practise male circumcision have a lower incidence than those who do not, favouring the view that partial protection is provided by this custom. Herpes simplex virus type 2 remains a candidate oncogenic agent, but the results of comparative seroepidemiological surveys of titres among cases and controls are inconsistent, not only in Uganda, but also in other areas of the world. Human papillomaviruses are clearly more important. Analyses of the geographical and age distribution of cancer in Uganda, based on the results of a country-wide biopsy service, show that cervical cancer and cancer of the vulva, vagina, and penis share common causes and are related to genital warts. Recently, a number of different papillomaviruses have been found in various forms of squamous-cell neoplasia of the genital tract, and similar studies would be worthwhile in tropical Africa.