Correlation of p16^INK4A overexpression with human papillomavirus infection in cervical adenocarcinomas

As human papillomavirus (HPV) infection is the main risk factor for squamous cell carcinoma of the cervix and overexpression of p16^INK4a occurs when retinoblastoma protein is inactivated by high-risk HPV, the authors studied the association of HPV infection and expression of p16^INK4a in cervical adenocarcinomas. Specimens of cervical glandular neoplasias were immunostained with a p16^INK4a-specific monoclonal antibody (clone E6H4). Approximately 80% of glandular neoplasms showed overexpression of p16^INK4a. Exfoliated cells from 14 adenocarcinomas were further examined by p16^INK4a-specific immunocytochemistry, and 12 cases showed overexpression of p16^INK4a, suggesting that immunostaining for p16^INK4a may be a useful diagnostic tool for cervical adenocarcinomas. The authors further examined HPV DNA in cervical adenocarcinomas with the polymerase chain reaction method. Overexpression of p16^INK4a was positive in 94% of cases in which HPV16 or 18DNA was positive, a finding suggesting that HPV16 or 18 may play an important role in cervical adenocarcinomas. Overexpression of p16^INK4a may be an indicator of pathogenic activity of high-risk HPVs.