Pages: 199-208DOI: http://dx.doi.org/10.31975/NJBMS.2018.8405
Date of Publication: 30-Nov--0001
Ki - 67 and p53 - Novel Prognostic Biomarkers in Surface Epithelial Ovarian Tumors
Author: Lavanya Rajagopal, Veena Raja, Sundaram Arunachalam, Shivashekar Ganapathy
Background: 70% of the women diagnosed with ovarian carcinoma have advanced disease because of ineffective screening tools. The proliferative activity of ovarian carcinoma is a valuable indicator of tumor aggressiveness. Ki-67 is an excellent marker to determine the growth fraction. p53 suppressor gene has an essential role in controlling cell cycle and initiating carcinogenesis.
Aim: To evaluate the proliferative activity using Ki-67 index and to correlate with histological subtype, grade, Federation of Gynecology and Obstetrics (FIGO) stage, and p53 overexpression by immunostaining in surface epithelial ovarian tumors.
Materials and Methods: This 3 year prospective study was undertaken in the Department of Pathology, Vinayaka Missions, Salem and approved by ethical committee. 47 cases of surface epithelial ovarian tumors were evaluated in this study. The proliferation expression related to Ki-67 antigen was evaluated by immunohistochemical monoclonal MIB-1 antibody. In each case, p53 immunostaining was done along with Ki-67 labeling index (Ki-67 LI) which was calculated as percentage of positively stained cells using high power objective of the microscope (x400).
Results: Among the 47 cases, the final histopathological diagnosis showed that 16 were benign , 10 were borderline, 16 were malignant and 5 were undifferentiated tumors. Immunostaining for Ki 67 and p53 was done for all selected 47 Surface Epithelial Ovarian Tumors (SEOT) cases. The difference in the mean Ki-67 labelling index between benign (2.9%), borderline (7.2%), and malignant epithelial tumors (37.5%) were statistically significant (p =<0.001). High labeling index of Ki-67 was noted with advanced FIGO stage. p53 was positive in 25 cases which was more frequent in serous adenocarcinomas than mucinous adenocarcinomas. p53 positivity was statistically significant between benign, borderline, and malignant epithelial tumors (p =<0.001).
Conclusion: In surface epithelial tumors of ovary histological grade and FIGO stage when combined with Ki-67 LI and p53 in histopathology report would help in diagnostic differentiation of subtypes, prognosis, deciding the need for adjuvant chemotherapy and in predicting the survival analysis. Both these biomarkers are very much useful to identify borderline tumors which are likely to behave in a malignant fashion.
Keywords: Surface epithelial ovarian tumors, Ki-67, p53