Is p16INK4A expression more useful than human papillomavirus test to determine the outcome of atypical squamous cells of undetermined significance-categorized Pap smear? A comparative analysis using abnormal cervical smears with follow-up biopsies

The results indicate that there is a close association between weak or strong p16 expressions in ASCUS-categorized smears with the presence of SILs in follow-up biopsies and positive HR-HPV viral loads. Conversely, there is also a clear association between the lack of p16 expression and the absence of significant lesions in follow-up biopsies, but this is not consistent with a negative HR-HPV viral load. It is concluded that p16 expression is an indicator of pathogenic activity of HR-HPV, which is an objective biomarker for clarification of ASCUS-categorized Pap smears in gynecological cytopathology. Furthermore, through comparative analysis, directly visualized p16 immunostaining on smears appears to be a more effective method than HR-HPV viral load for the detection of reactive changes and LSILs from ASCUS-categorized Pap smears.