Prevalence of cervical intraepithelial neoplasia grades II/III and cervical cancer in patients with cytological diagnosis of atypical squamous cells when high-grade intraepithelial lesions (ASC-H) cannot be ruled out.

CONTEXT AND OBJECTIVE

The latest update of the Bethesda System divided the category of atypical squamous cells of undetermined significance (ASCUS) into ASC-US (undetermined significance) and ASC-H (high-grade intraepithelial lesion cannot be ruled out). The aims here were to measure the prevalence of pre-invasive lesions (cervical intraepithelial neoplasia, CIN II/III) and cervical cancer among patients referred to Instituto Fernandes Figueira (IFF) with ASC-H cytology, and compare them with ASC-US cases.

DESIGN AND SETTING

Cross-sectional study with retrospective data collection, at the IFF Cervical Pathology outpatient clinic.

METHODS

ASCUS cases referred to IFF from November 1997 to September 2007 were reviewed according to the 2001 Bethesda System to reach cytological consensus. The resulting ASC-H and ASC-US cases, along with new cases, were analyzed relative to the outcome of interest. The histological diagnosis (or cytocolposcopic follow-up in cases without such diagnosis) was taken as the gold standard.

RESULTS

The prevalence of CIN II/III in cases with ASC-H cytology was 19.29% (95% confidence interval, CI, 9.05-29.55%) and the risk of these lesions was greater among patients with ASC-H than with ASC-US cytology (prevalence ratio, PR, 10.42; 95% CI, 2.39-45.47; P = 0.0000764). Pre-invasive lesions were more frequently found in patients under 50 years of age with ASC-H cytology (PR, 2.67; 95% CI, 0.38-18.83); P = 0.2786998). There were no uterine cervical cancer cases.

CONCLUSION

The prevalence of CIN II/III in patients with ASC-H cytology was significantly higher than with ASC-US, and division into ASC diagnostic subcategories had good capacity for discriminating the presence of pre-invasive lesions.