The challenges involved in conducting epidemiologic studies of cancer in developing countries can be and often are unique. This article reports on our experience in performing a case-control study of invasive cervical cancer in four Latin American countries (Columbia, Costa Rica, Mexico, and Panama), the summary medical results of which have been published in a previous issue of this journal (1). The study involved a number of principal activities--mainly selecting, conducting interviews with, and obtaining appropriate biologic specimens from 759 cervical cancer patients, 1,467 matched female controls, and 689 male sex partners of monogamous female subjects. This presentation provides an overview of the planning and methods used to select the subjects, conduct the survey work, and obtain complete and effectively unbiased data. It also points out some of the important advantages and disadvantages of working in developing areas similar to those serving as locales for this study.

A study of 759 cervical cancer patients, 1,430 controls, and 689 sex partners in four Latin American countries has made it possible to assess the influence of multiple factors upon the risk of invasive cervical cancer. The principal risk factors identified were the woman's age at first coitus, the number of her steady sex partners, her number of live births, the presence of DNA from human papillomavirus (HPV) types 16 or 18, a history of venereal disease, nonparticipation in early detection programs, and low socioeconomic status. There is good reason to believe that extensive detection programs directed mainly at high-risk groups in the Americas can reduce the high incidence of cervical cancer in this Region.

Human papillomavirus (HPV) types 16 and 18 have been implicated as risk factors for cervical dysplasla and neoplasia. However, most studies have been observational, uncontrolled and conducted in populations at low risk for invasive cancer. We r sport a pilot case‐control study of incident invasive cervical cancer in Panama, Costa Rica and Bogota, Colombia. Between July and September 1985 we enrolled 46 consecutive newly diagnosed invasive cervical cancer cases and 51 age‐matted control women. Subjects were interviewed and samples collected for HPV DNA assays. HPV infection was defined by a filter in situ DNA hybidization technique under non‐stringent and stringent conditions against HPV‐6/11, 16 and 18 DNA probes. More cases (91 %) than controls (63%) had HPV DNA detected (non‐stringent) and more cases than controls had HPV‐16 or 18 DNA (67% vs. 43%, p = 0.02). Age at first intercourse was the most significant risk factor for HPV 16/18 Infection in all subjects. Smoking was significantly associated with cervical cancer (52% of cases vs. 27% controls) but was not associated with HPV infection.