Sex and cervical cancer.

Carcinoma of the cervix is a major health problem throughout the world.After breast cancer, it is the second commonest malignancy in women, with an incidence of about half a million cases a year.In some localities-Africa, India, and certain other Asian countries-it is the commonest cancer in women; in Europe and North America it is the fourth common- est.' Data from some developed countries show a reduction in cervical cancer mortality of about 30% between 1960 and 1980, presumably because of early diagnosis through screening programmes.2In England and Wales, however, there has been only a small decline in deaths from this cause in the past 20 years, and 2000 women a year still die of it.3During the past decade there has been a pronounced increase in cervical intraepithelial neoplasia (CIN), particularly in young women,45 and Beral, using a computer model, has predicted a 60% increase in cervical cancer registrations and a 70% increase in mortality in women aged under 50 in 10 years' time.6 Squamous carcinoma of the cervix is the culmina- tion of CIN, which is a series of progressive epithelial changes.Although the pathogenesis of these changes is not well understood, the cytology and histology of CIN is clear,7 and invasive cancer of the cervix could be completely prevented if CIN was detected by screening tests and treated correctly.Epidemiological studies have made it possible to define some behavioural and other characteristics of women who are at relatively high risk ofcervical cancer, and recent advances in basic science have clarified, at least in part, the aetiology of the disease.The purpose of this paper is to review this evidence with particular reference to women who attend clinics for sexually transmitted diseases, and to look for ways in which the services in these clinics can be used or modified to reduce the likelihood of invasive cervical disease in this group.