Factors influencing histologic confirmation of high-grade squamous intraepithelial lesion cytology

OBJECTIVE: To examine the predictors of histologic confirmation of high-grade squamous intraepithelial lesion (HSIL) cytology occurring in follow-up of young women originally referred into a trial because of less severe cytology. METHODS: We used enrollment HSIL cytology (N=411) as read by clinical center pathologists for women participating in the ASCUS-LSIL Triage Study (ALTS). The primary outcome was histologic cervical intraepithelial neoplasia (CIN) grade 3 and early cancer (n=195; 191 CIN 3 and four cancers) as diagnosed by the Pathology Quality Control Group during the 2-year duration of ALTS. RESULTS: The 2-year absolute risk of CIN 3 or worse after an HSIL cytology was 47.4% (95% confidence interval 42.5-52.4%). The 2-year absolute risk of CIN 3 or worse was lowest (14.3%) for women who were human papillomavirus (HPV)-16-negative, had colposcopic impression of less than low-grade, and whose HSIL cytology as called by the clinical center was not also called HSIL or equivocal HSIL cytology by the Pathology Quality Control Group. The 2-year absolute risk of CIN 3 or worse was highest (82.4%) for women who were HPV16-positive, had colposcopic impression of low-grade or worse, and whose HSIL cytology also was called HSIL or equivocal HSIL cytology by the Pathology Quality Control Group. CONCLUSION: Histologic confirmation of precancer among young women with HSIL cytology was more likely when other risk factors (eg, HPV16) for cervical precancer were present.