Identification of papillomavirus types and other risk factors for cervical intraepithelial neoplasia - Revista Brasileira de Ginecologia e Obstetrícia

PURPOSE: to identify risk factors for cervical intraepithelial neoplasia (CIN) and human papillomavirus (HPV) types among women with CIN, and to compare with HPV types among patients with normal cervix. METHODS: a total of 228 patients were studied, of whom 132 with CIN (cases) and 96 with normal cervix (controls). In the two groups consisting of women selected among outpatients attended in the same hospital, living near the place of the research, mean ages were similar (34.0±8.3 years) and there was a predominance of married women. Possible risk factors for CIN were investigated with the application of a questionnaire surveying age, marital status, level of schooling, age at first coitus, number of pregnancies, number of sexual partners, method of used contraception, reference of previously sexually transmitted diseases (STDs) and smoking habits, with a comparison between the studied groups. Samples were collected for oncologic colpocytology and HPV search through polymerase chain reaction (PCR), using MY09/MY11 primers; then colposcopic and histopathological examinations were performed. For statistical analysis of the association between risk factors and CIN, odds ratio with 95% confidence interval and chi2 and Fisher tests were used at a significance level of 0.05. The logistic regression method with the significance expressed by the p value with maximum likelihood was also applied. RESULTS: the following variables remained in the logistic regression model: HPV infection of high oncogenic risk (OR=12.32; CI 95%: 3.79-40.08), reference of previous STDs (OR=8.23; CI 95%: 2.82-24.04), early age at first coitus (OR=4.00; CI 95%: 1.70-9.39) and smoking habit (OR=3.94; CI 95%: 1.73-8.98). PCR was positive in 48.5 and 14.6% in the case and control groups, respectively. CONCLUSIONS: the main risk factor for CIN was oncogenic HPV infection, with types 16, 18, 33, 35, 51, 52, 58, and 83. Among patients with a high-degree lesion, there was a predominance of HPV-16 or type 16 variant. In patients with normal cervix oncogenic, HPV types 51, 58, and 51 variant were also identified.