Cancer of the cervix. Some aspects of epidemiology, screening, risk factors and survival.

Early statistics on the occurrence of cancer of the cervix are unreliable. What is certain is that between 1950 and 1965 incidence rates (IRs) and mortality rates (MRs) fell considerably in most Western populations. Recently, however, rates in the 15-35-year age group of some populations have risen two- to threefold. In some developing populations, especially in South America and Africa, rates are very high--up to eight times those in most Western populations. Risk factors include early age at first intercourse, low socio-economic state, having multiple partners, smoking, being widowed or divorced, and having a husband who has had multiple partners. The modus operandi of carcinogenesis is not known. Screening, using the Papanicolaou test, has markedly reduced the IRs and MRs, particularly in certain Scandinavian populations. In Western populations 40-60% of patients attain 5-year survival. Understandably, in individual patients the crucial regulating factor is the stage of disease when diagnosed. Among those at stage I, 70-90% survive for 5 years or more, whereas only 0-25% of patients diagnosed at stage IV do. In Soweto, Johannesburg, length of survival in a series of black patients whose staging pattern did not markedly differ from that in Western series was less than half that in the latter. Undoubtedly, as repeatedly urged, appropriate selective screening and health education could effectively reduce the toll of mortality, especially in high-risk developing populations.