Description of a seven-year prospective study of human papillomavirus infection and cervical neoplasia among 10 000 women in Guanacaste, Costa Rica Descripción de un estudio prospectivo de siete años sobre la infección por el virus del papiloma humano y el cáncer cervicouterino en 10 000 mujeres de Guanacaste, Costa Rica

• Main Authors: M. Concepción Bratti, Ana C. Rodríguez, Mark Schiffman, Allan Hildesheim, Jorge Morales, Mario Alfaro, Diego Guillén, Martha Hutchinson, Mark E. Sherman, Claire Eklund, John Schussler, Julie Buckland, Lidia A. Morera, Fernando Cárdenas, Manuel Barrantes, Elmer Pérez, Thomas J. Cox, Robert D. Burk, Rolando Herrero
• Format: Article in Journal/Newspaper
• Language: English; Spanish; Portuguese
• Published: Pan American Health Organization 2004
• Subjects: Carcinoma; papillomavirus; human; precancerous conditions; risk factors; epidemiologic methods; Costa Rica; Medicine; R; Arctic medicine. Tropical medicine; RC955-962; Public aspects of medicine; RA1-1270; Arctic
• Online Access: https://doaj.org/article/84fca72fc24f4d5ca139c015afc5380c

OBJECTIVE:The Guanacaste study ("Guanacaste Project," or GP), was designed to investigate the role of human papillomavirus (HPV) infection and its cofactors in the development of cervical neoplasia and to evaluate new cervical cancer screening technologies. The follow-up phase of the GP was designed to study why a small proportion of women infected with HPV develop cervical intraepithelial neoplasia grade 2 (CIN 2), CIN 3, or cancer (these three together are globally referred to as > CIN 2, that is, CIN 2 or worse). The purpose of this article is to describe this prospective study in detail and to present the preliminary findings regarding the incidence of cervical neoplasia. METHODS: A cohort of 10 049 randomly selected women from 18 to 97 years old from Guanacaste, a province in northwestern Costa Rica, was intensively screened in 1993-1994 and then followed up for seven years after being enrolled. A questionnaire for demographic and risk factors was administered, and a pelvic examination was performed on sexually active women at each follow-up visit in order to obtain samples for screening tests and for research purposes. The final diagnosis given at the end of the enrollment phase categorized women into several groups according to the perceived risk of their developing either high-grade precursors of cancer or cancer. These groups were followed up at different intervals according to the risk of developing > CIN 2. The most active follow-up (every 6-12 months) was concentrated on the women most likely to develop > CIN 2, based on cytology (n= 492). The remainder of the cohort was followed either annually (n= 2 574) or after five to seven years of passive follow-up (n= 3 926). All women with possibly severe lesions detected by any technique were referred to colposcopy for further evaluation and treatment, and they were also censored from the study. Lesions >CIN 2 served as both the censoring outcome and our surrogate for cancer risk. RESULTS: Participation during follow-up was high (near 90%). ...