Publication:

P16, Ki67 and P63 staining pattern in squamous metaplasia, CIN and cervical cancer

Background Persistent infection with Human Papilloma Virus (HPV) has been the main cause of squamous intra epithelial neoplasia which in turn leads to cancer. The incidence is 28.0%. Early identification of dysplasia and malignancy helps early intervention.

Methods To do Immunohistochemical staining using P16ink4a, Ki 67, and P63 in cervical squamous metaplasia, CIN I, II, III and correlate the H and E features with IHC patterns. Study was carried out in SRM Medical College Hospital and Research centre, Kattankulathur, Tamil Nadu, a descriptive study for a period of 2 years (2012 to 2014) on formalin fixed paraffin embedded tissues from cervix. H and E sections of uterine cervix were categorized into squamous metaplasia, CIN I, CIN II, CIN III and squamous cell carcinoma. 50 representative samples were subjected to Four-micrometer-thick sections and subjected to IHC using PathInsitu, using P16ink4a, Ki67 and P63. Statistics: Using SPSS for windows (V.17). Data expressed by number and percentage. Methods used were Chi square test, Screening test and ROC curve. Statistical significance was 0.05.

Results P63 has shown to be the best marker out of the three to distinguish the progression of a lesion towards dysplasia and malignancy in cervix. Ki 67 showed a specificity of 84.2% with a negative predictive value of 59.3%, and an ROC curve area of 69.2%. In this study, Ki67 showed lesser sensitivity than that of P63.

Conclusions P16 identifies HPV 16 infection in uterine cervix. Ki67 and P 63 are helpful in determining the nature of progression of lesion. High expression of Ki 67 indicates a neoplastic progression. P63 may be used to differentiate benign from malignant lesions. P16 with P63 showed good results in predicting the progression of a lesion.