Evaluation of Risk-based Colposcopy for Cervical Precancers Detection in the ASCUS LSIL Triage Study [40B

Abstract

INTRODUCTION: To validate previously shown improved efficiency of cervical precancers detection by risk-based colposcopy-biopsy in the Biopsy Study. METHODS: Included in the study were 2,453 women with ASCUS or LSIL referral cytology in the HPV triage and immediate colposcopy arms who underwent enrollment colposcopy. Enrollment cytology, HPV genotyping, and colposcopy impressions were used to establish 12 risk strata. Up to four lesion-directed cervical biopsies were taken during enrollment colposcopy. Primary outcomes were cervical intra-epithelial neoplasia grade 2 or worse disease detected by colposcopy-guided cervical biopsies at baseline and during the two-year follow up. RESULTS: The risk of detecting CIN2 or worse disease ranged from 1-85.5% across the 12 risk strata based on colposcopy impressions, study cytology, and HPV 16 status. As in the Biopsy Study, the lowest risk stratum (normal/acetowhite or benign abnormality, <HSIL cytology, and HPV 16 negative) falls below the clinical risk threshold to perform colposcopy by ASCCP guidelines; the same four risk strata with at least two of the high-risk categories (high-grade colposcopy impression, high-grade squamous intraepithelial lesion cytology, or HPV 16 positive) exceed the ASCCP recommended threshold for immediate treatment. Overall, 60-80% of women continued in the two-year study period. Except for the highest-risk strata, the negative predictive value of a negative enrollment colposcopy ranged 82.4-96% during follow-up. CONCLUSION: We show that data from the ASCUS-LSIL Triage Study confirm the risk-based colposcopy approach to improve detection of cervical precancers. Taking multiple biopsies reassures against missed disease and women with negative colposcopy may return to routine screening.