Efficacy of p16 and Ki-67 immunostaining in the detection of squamous intraepithelial lesions in a high-risk HPV group.

p16 and Ki-67 immunohistochemistry can be used as an ancillary method for the diagnosis of squamous intraepithelial lesion (SIL) versus atrophic change and atypical squamous metaplasia. The aim of the present study was to evaluate the efficacy of these two immunohistochemical markers in the accurate interpretation of cervical biopsies and correlate this data with human papilloma virus (HPV) infection status. The study included 103 formalin-fixed cervical punch and cone biopsy samples, with corresponding HPV DNA test data. Histopathological staining with hematoxylin and eosin, and immunohistochemical staining for p16 and Ki-67 were reviewed by two pathologists. The positivity of p16 and Ki-67 increased significantly with the severity of the cervical lesion in patients with a high-risk-HPV (HR-HPV) infection status (P<0.001). However, there was discordance in the HPV-negative group. Furthermore, concomitant diffuse, strong and block positive staining of p16, and a high Ki-67 index were implicated in high-grade SIL in the HR-HPV group. Thus, the two markers were efficient in advancing the diagnostic accuracy of cervical biopsies in the HR-HPV group; however, application of immunohistochemical results should be carefully considered in the HPV-negative group.