The 2001 American Society for Colposcopy and Cervical Pathology Consensus Guidelines recommend that women who have Papanicolaou (Pap) smears diagnosed as atypical squamous cells (ASC), cannot exclude high-grade squamous intraepithelial lesion (HSIL) (ASC-H) should be referred for immediate colposcopic examination. The objective of this pilot study was to evaluate whether reflex human papillomavirus (HPV)-DNA testing performed on smears diagnosed as ASC-H may obviate the need for immediate colposcopic examination.
All ThinPrep Pap smears that were diagnosed as ASC-H or atypical squamous metaplastic cells (ASMT) between 2001-2003 and that had HPV-DNA testing and subsequent histologic and/or cytologic follow-up were evaluated. Those smears that were diagnosed as ASMT were reviewed and reclassified under the 2001 Bethesda System as either ASC of undetermined significance (ASCUS) or ASC-H. Smears that were diagnosed as ASCUS were excluded from the study.
The study included of 48 smears that were diagnosed as ASC-H. All patients with biopsy-proven HSIL had positive high-risk (HR)-HPV results (100% negative predictive value). Approximately 80% of patients with ASC-H who had biopsy-proven, low-grade intraepithelial lesion on follow-up had positive HR-HPV results. Among the patients who had ASC-H with negative follow-up, 50% had positive HR-HPV results, and 50% had negative HR-HPV results.
Among patients with ASC-H, a negative HR-HPV result was found to be an excellent predictor of the absence of HSIL. The results of this pilot study suggested that HPV-DNA testing may serve as a means to better select which patients with ASC-H on Pap smear should undergo colposcopic examination. This approach potentially may reduce medical costs and eliminate the need for routine colposcopic examination among patients with ASC-H Pap smears.