Potential diagnostic value of P16 expression in premalignant and malignant cervical lesions

Background: the goal of this study was to evaluate the results of the expression of p16ink4a in normal uterine cervical epithelium, low-grade cervical intraepithelial neoplasia (cin), high-grade cin, squamous cell carcinoma (scc), and adenocarcinoma of the cervix, in order to help draw a distinction between low risk and high risk patients with cervical lesions. materials ans methods: p16ink4a expression was evaluated by immunohistochemistry in 78 paraffin-embedded tissue samples including 39 normal cervical tissues, 11 low-grade cins, 11 high-grade cins, 22 cervical sccs and 8 cervical adenocarcinomas. two parameters in immunohis- tochemical p16 expression were evaluated: percentage of p16-positive cells, and reaction intensity. results: the p16ink4a expression rate was 81.8% in low-grade cins, 91% in high-grade cins, 90% in sccs and 75% in cervical adenocarcinomas. 10% of nor- mal cervical samples expressed p16. moreover, there was a significant relationship between the histological diagnoses and percen- tage of positive cells and reaction intensity of p16 (p < 0.005). the intensity of the reaction was the best parameter to evaluate the positivity of p16. conclusions: over-expression of the p16ink4a was typical for dysplastic and neoplastic epithelia of the uterine cervix. however, p16ink4a-negative cins and carcinomas did exist. although negative p16ink4a expression does not definitely exclude the patient with cervical lesion from the high-risk group, immunohistochemical study for p16ink4a may be used as a supplementary test for an early diagnosis of cervical cancers.