The utility of p16 INK4a and Ki-67 to identify high-grade squamous intraepithelial lesion in adolescents and young women.

ABSTRACT

Background: The repair of the immature squamous epithelium following HPV infection may mimic HSIL in adolescent women. Aim: to study the utility of p16 INK4a and Ki-67 in diagnosis of cervical squamous lesions in adolescents and young adults. Materials and Methods: In a cross-sectional study, the evaluation of p16 INK4a and Ki-67 immunohistochemistry was performed on 72 cervical biopsies of adolescents and young adults women diagnosed as negative for malignancy and intraepithelial lesion (NML) (n = 18) or positive for low grade (LSIL) (n = 31) and high grade (HSIL) (n = 23) squamous intraepithelial lesions in two references services in Fortaleza-Brazil. Data was evaluated using Fisher's test and Kappa index. Results: p16 INK4a was positive in 81% of HSIL, 19% of LSIL and in no NML (P < 0.0001). Ki-67 was positive in 74%, 32% and 5.5% of HSIL, LSIL and NML, respectively. p16 INK4a and Ki-67 in the diagnosis of HSIL showed high sensitivity and negative predictive value. Kappa index was very good for p16 INK4a (k = 0.72). Conclusions: In adolescents and young adults p16 INK4a alone or with Ki-67 represents important tool to reduce mistaken diagnosis of HSIL and to avoid overtreatment.