Epidemiology of uterine cervical cancer.

The epidemiology of cervical cancer presents a number of unique challenges, mainly with respect to disentangling correlated factors and to elucidating biological mechanisms. The available evidence suggests a complex multifactorial etiology, although the relative contributions of risk factors and their interactions remain obscure. Infectious agents are strongly suspected, but as yet not conclusively identified. It is also unclear whether there are subgroups of women or periods of life that are most susceptible to the action of infectious agents, and the contribution of the "male factor" needs to be defined. Several epidemiologic leads can be pursued through biochemical and molecular techniques. Most promising is the recent evidence linking certain HPV types to cervical abnormalities, including cancer, and newly developed probes can be incorporated into epidemiologic studies to evaluate an array of risk factors. Endocrine and metabolic assays may be helpful in clarifying the role of exogenous and possibly endogenous hormones. The effects of cigarette smoking may be further evaluated by studying constituents of tobacco smoke and their metabolites in cervical mucus. Finally, the relationship of diet to cervical cancer should be assessed by examining the levels of micronutrients, trace minerals, and other nutritional indices in body tissues and fluids, as well as through interview data. An understanding of cervical cancer etiology will require a better identification of risk factors for precursor lesions as well as factors that enhance their progression to invasive cancer. Through studies that focus on disease stage and time-related events, it should be possible to clarify the multi-stage processes involved in cervical carcinogenesis, and those factors that may inhibit as well as promote transition rates. The protective effects of screening programs deserve further attention, and research into dietary factors may lead in time to nutritional intervention. Investigation by cell type should also be pursued to define the epidemiology of the rarely occurring adenocarcinomas and adenosquamous carcinomas of the cervix. Finally, preventive strategies should be targeted to high-risk populations, especially those of the lower socioeconomic classes and with limited access to medical care. The need for a renewed focus on epidemiology and prevention is emphasized by recent increases in exposure to several postulated risk factors, including sexual promiscuity, oral contraceptives, and smoking.(ABSTRACT TRUNCATED AT 400 WORDS)