Evaluation of p16, human papillomavirus capsid protein L1 and Ki-67 in cervical intraepithelial lesions: potential utility in diagnosis and prognosis.

Cervical dysplasia, a potentially precancerous lesion, has increased in young women. Detection of cervical dysplasia is important for reducing morbidity and mortality in cervical cancer. This study analyzes the immunohistochemical expression of p16, HPV L1 capsid protein and Ki-67 in cervical intraepithelial lesions, and correlates them with lesion grade to develop a set of markers for diagnosis and detect the prognosis of cervical cancer precursors. Seventy-five specimens were analyzed, including 15 cases of CIN 1, 28 cases of CIN 2, 20 cases of CIN 3, and 12 cervical squamous carcinomas, besides 10 normal cervical tissues. They were stained for p16, HPV L1 and Ki-67. Sensitivity, specificity, predictive values and accuracy were evaluated for each marker. p16 expression increased during progression from CIN 1 to carcinoma. HPV L1 positivity was detected in CIN 2 and decreased gradually as the CIN grade increased but disappeared in carcinoma. Strong Ki-67 expression was observed in high grades CIN and carcinoma. p16, HPV L1 and Ki-67 were sensitive but with variable specificity in detecting CIN lesions. p16, HPV L1 and Ki-67 are useful markers in establishing the risk of high-grade CIN. They complete each other to reach an accurate diagnosis and to detect the prognosis.