Human papillomaviruses, cervical cancer and the developing world.

Carcinoma of the uterine cervix is the commonest cancer of women in the majority of developing countries; in developed countries it is much less common, as well as being less frequent than some other cancers, such as those of breast, lung and colon. The discovery of human papillomavirus (HPV) as an aetiological agent of cervical cancer (and of other anogenital malignancies) has prompted a great deal of interest in the biology and oncogenicity of this virus, including large-scale epidemiological surveys comparing the prevalence of HPV and other possible causative agents between areas of high and low incidence of cervical carcinoma. These studies have thrown up tantalizing clues concerning the virus' pathogenesis and disease associations. Sexual practices, parity, diet, smoking, other diseases (including sexually transmissible diseases) and immunogenetic characteristics may all play a contributory role in the development of cervical carcinoma. These factors may be independent of each other and of association with HPV infection. Immunization to prevent papillomavirus infection and thus cervical cancer is an attractive prospect. Although the potential in using such an approach has been demonstrated in several animal models, there are several major theoretical problems to solve before HPV vaccination becomes a practicality. Intervention to prevent exposure to other aetiological factors and to improve screening may be a more practicable strategy for reducing the burden of cervical cancer.