There is need for more objective diagnostic parameters to identify cervical dysplastic or neoplastic cells. So, we examined the p16(INK4A) expression in the cervical tissues to evaluate the value of p16(INK4A) as a diagnostic parameter.

We examined the p16(INK4A) expression by immunohistochemical staining in normal cervical tissues (n=3), preneoplastic lesions (n=6), carcinoma in situ (CIS, n=5), and invasive carcinomas (n=5) of the cervix, which were selected randomly by H and E staining from the archives of formalin-fixed and paraffin-embedded tissues and we also examined the status of human papillomavirus (HPV) infection in the same tissues.

The positive rates of p16(INK4A) expression was significantly higher in all abnormal cervical tissues including subclinical papillomavirus infection (SPI), dysplasia, CIS, and invasive carcinoma than in normal cervical epithelium (p=0.001). Despite the strong expression of p16(INK4A) in the area of CIS, no expression of p16(INK4A) was observed in the area of normal epithelium in the vicinity of CIS. 11 cases among 19 cases of examined tissue samples were tested for HPV infection. Seven of them showed positivity for HPV DNA.

We herein demonstrated that p16(INK4A) would be a sensitive and specific marker for the abnormal cervical cells in tissue sections. This approach will help to reduce interobserver variations in the histopathologic interpretation of cervical biopsy specimens.