Immunohistochemical expressions of p16 and p53 proteins in cervical intraepithelial neoplasia and in benign cervical tissue.

Purpose Of Investigation: To evaluate the immunohistochemical expressions of p16 and p53 in cervical intraepithelial neoplasia (CIN) and do a comparison with non-neoplastic cervical lesions.

Methods: Sixty cases diagnosed as CIN after histopathological examination and 25 controls diagnosed as chronic cervicitis were included in the study. Immunohistochemical expressions for p16 and p53 were evaluated and compared in all cases. The cases in the study were defined according to the Bethesda system. Of these, 31.8% (n = 27) had a low-grade squamous intraepithelial lesion (LGSIL), and 38.8% (n = 33) had a high-grade squamous intraepithelial lesion (HGSIL).

Results: There was a statistically significant difference between chronic cervicitis and CIN in terms of p53 and p16 expression levels (p = 0.001). On the other hand, the level of p16 expression was statistically different between LGSIL and HGSIL (p = 0.001), while there was no significant difference in terms of p53 expression. Among the HGSIL cases (n = 33), 91% had p16 expression, while 66.7% (n = 27) of the LGSIL patients had no p16 expression. In the chronic cervicitis group, 84% (n = 21) did not reveal any p16 expression, while 96% (n = 24) did not reveal any p53 expression. Various levels of p53 expressions were detected in 59.2% (n = 16) of CIN1 cases, 69.3% (n = 9) of CIN2 cases, and 90% (n = 18) of CIN3 cases.

Conclusion: While p16 is useful in detecting high-grade cervical lesions, p53 is not a good biomarker for distinguishing high-grade lesions from low grade ones.