Objective: To evaluate cervical intraepithelial neoplasia (CIN) treatment failure among women with an altered Papanicolaou test and treated at a public cervical pathology center in Rio de Janeiro, Brazil.

Methods: An exploratory study was carried out in a cohort of women treated for preinvasive cervical cancer, from 1998 to 2000. Epidemiological, clinical, and sociodemographic data were obtained from medical records. Information related to cytological and histological examinations, classified according to the Bethesda System, were cross-tabulated with reports from the main cervical pathology laboratory at the Brazilian Cancer Institute. Conditional probability for treatment failure (12 and 24 months) and hazard ratios were estimated through Kaplan-Meier (log-rank test, 95%) and Cox regression (entry, ≤0.05; removal, ≥0.10).

Results: Mean (SD) follow-up period was 20.75 (20.53) months, and 449 women were treated for CIN-1 or CIN-2/3. There was an increased probability of treatment failure according to age group (37.19% and 57.44% in 12 and 24 months for women >50 years). Women who smoked for more than 10 years were more likely to present treatment failure compared with those who smoked for up to 10 years (33.56% and 22.01% in 12 months; 53.15% and 42.59% in 24 months, respectively). Women older than 50 years showed an independent risk for treatment failure (adjusted hazard ratio, 1.59; 95% confidence interval, 1.04-2.41) compared with women aged between 10 and 29 years.

Conclusions: Age (>50 years) was statistically associated with treatment failure. Duration of tobacco use (>10 years), CIN-2/3 cytology at treatment, glandular involvement, and having more than 4 sexual partners in a lifetime were also associated with failure, reducing statistical significance after adjustment.