Immunohistochemical expression of P16 and Ki-67 in uterine cervical neoplasms

Abstract

To study the expression of Ki-67 and p16 in neoplastic lesions of uterine cervix and to evaluate the prognostic significance of tumour differentiation, histological type, stage and grade, depth of tumour invasion and lymphovascular invasion in women with neoplasia of uterine cervix. This study was performed on 50 biopsies and surgically resected specimens of uterine cervix, which were fixed in 10% formalin, processed, paraffin embedded and cut into 3-5 microns thickness, stained with hematoxylin and eosin stains and immunohistochemical staining by p16 and Ki-67 antibodies was performed and studied. Majority of cases of invasive carcinoma cervix were large cell non-keratinizing squamous cell carcinoma, 58 cases (48.2%). Majority of cases of invasive carcinoma cervix were seen in stage 2B, 40 (40.8%) cases followed by stage 3B, 24 (24.4%) cases. Out of 18 cases of large cell non-keratinizing squamous cell carcinoma, 12 (66.7%) showed 3+ positivity for Ki-67. 7 (53.8%) cases of stage 2A showed 3+ positivity, 3 (23.1%) cases each showed 2+ positivity for p16. 7 (36.8%) cases of moderately differentiated SCC showed 3+ positivity, 4 (21.1%) showed 2+ positivity and 5 (26.3%) showed 1+ positivity of Ki-67. Out of 10 stable patients, 4 (40.0%) showed negative p16 immunoexpression and all the 3 cases (100%) with recurrence showed 2+ positivity and 2 (100%) patients with metastasis showed 3+ positivity. Out of 10 stable patients, 6 (60%) showed negative Ki-67 immunoexpression and all the 3 (100%) cases with recurrence showed 3+ positivity and one each (50.0%) patient with metastasis showed 2+ positivity and 3+ positivity. p16 and Ki-67 immunomarkers are useful as a diagnostic and prognostic tool in cases with recurrence and metastasis, helping in early detection of disease progression.