Higher homocysteine and lower serum levels of α-tocopherol are risk factors for cervical dysplasia in women living in São Paulo, Brazil.

A163

Background: Cervical cancer is the second most common cancer among women in Brazil. Previous studies in Brazil have shown that Human Papillomavirus (HPV) infection is the main causative agent of pre-invasive and invasive cervical lesions, with the additional contribution of co-factors, such as oral contraceptive use and high parity. It has been suggested also that carotenoids, tocopherols and folate can prevent precursors lesions but findings have not been uniformly replicated. Objective: Evaluate the association of serum micronutrients and cervical intraepithelial neoplasia grade III (CIN3). Design: Hospital based case-control study conducted in São Paulo, Brazil. Material and methods: Female patients from 3 large public hospitals were invited to participate. Cases were women diagnosed with CIN 3 confirmed via histopathology. Controls were these from the same hospitals without CIN, atypical squamous/glandular cells of undetermined significance (ASCUS/AGUS), or cancer. Blood samples were collected protected from light, and stored at -70°C before analyses of serum β-carotene, lycopene, vitamin A, α and γ-tocopherol, plasmatic vitamin B6 and homocysteine (hcy) by high performance liquid chromatography (HPLC). Cervical samples were tested for the presence of HPV DNA by polymerase chain reaction (PCR). Subjects completed a questionnaire about sociodemographic characteristics, life style, and medical history. Odds ratios (OR) and 95% confidence interval (95%CI) were calculated using logistic regression. All potential confounders were identified by a change-in-estimate criterion. Results: For this analysis, we included 475 women, aged 21-66 y (124 cases and 351 controls). HPV infection was a strong risk factor for CIN3 (OR=48.1, 95%CI: 21.4-107.9). The highest tertile of hcy was associated with risk for CIN3 (OR=2.65, 95%CI: 1.03-6.84) when compared to the lowest tertile, after adjusting for race, smoking, hospital, parity, cauterization and HPV infection. The lowest tertile of α-tocopherol was associated with risk for CIN3 (OR=3.71, 95%CI: 1.24-11.14) when compared to the highest tertile, after adjusting for hospital, race, age, education, age of sexual intercourse, number of sexual partners, parity and HPV. Conclusion: Higher hcy levels, a biomarker for nutritional status of folate, and lower serum levels of blood α-tocopherol were associated with risk for CIN3 independent of lifestyle and sociodemographic factors.