Expression of Ki67 in Triple Negative Breast Carcinoma and Its Correlation with Clinicopathological Variables – A Study from a Tertiary Care Center in Thrissur, Kerala
BACKGROUND Breast cancer is the most common malignancy in females. Triple negative breast carcinomas (TNBC), one of the molecular subtypes of breast carcinoma, are not sensitive to hormonal therapy and are reported to have aggressive behaviour. The present study was done to evaluate the expression of Ki67 in triple negative breast cancer using immunohistochemistry (IHC) and correlate the Ki67 expression with other clinicopathological variables. METHODS Based on the IHC status (ER, PR, HER neu), 50 triple negative breast carcinoma cases were selected from January 2019 to June 2020 for a cross-sectional study in Department of Pathology, Government medical college Thrissur. Ki67 immunohistochemical staining was done on the tissue sections and the Ki67 score was correlated with clinicopathological variables. RESULTS Of the 50 cases, majority (74 % cases) had high Ki67 expression (score of more than 50 %). High Ki67 score was strongly associated with presence of lymphovascular emboli (LVE) (P value < 0.05). Even though most of the patients were above 50 years (72 %), no significant correlation was seen between age and Ki67 score. The association with tumour size, histopathological type, tumour grade and lymph node status were not statistically significant. CONCLUSIONS Ki67 expression was high in triple negative breast cancer with mean score of 62 %. High Ki67 score correlated with presence of LVE. High Ki67 would predict increased proliferation of breast cancer cells and could be considered as a prognostic marker. KEYWORDS TNBC- Triple Negative Breast Cancer, Ki 67 Score, Clinicopathological Variables