COMPARISON OF CLINICOPATHOLOGICAL PARAMETERS WITH HISTOLOGICAL AND MOLECULAR CLASSIFICATION OF BREAST CANCERS

Abstract

BACKGROUND: This is a retrospective study of 60 cases, to detect the expression of ER, PR, HER2neu, CK5/6 and Ki67 proliferation index in breast carcinomas by immunohistochemical method and to determine the newer molecular classication. Few patients have recurrence inspite of being diagnosed under the category of low risk and few do well in the high risk group which can be attributed to the molecular level differentiation. AIM: The aim of this study is to categorize the patients under molecular classication, and to compare the clinicopathological parameters with it and to denote the signicance of targeted therapy. MATERIALS AND METHODS: A retrospective study of detecting the expression of the above said markers in modied radical mastectomy specimens received at a tertiary care centre during the period from January 2015 to June 2018. A total of 60 cases which included 30 of IDC NST and 30 cases of special variants were selected for immunohistochemical analysis. RESULTS: Out of the 60 cases studied, the most common was found to be the luminal A type comprising 37% and the least common was the luminal B and hybrid types each comprising 8%. The most common grade for HER2 was Grade III (50%). The association of histological grade with the molecular classication was statistically signicant with the p value of 0.01. Basal type (56%) had the highest incidence of N3 stage. ER, PR, HER2 neu, CK5/6 expression and proliferation index with Ki67 had a statistically signicant association with the molecular classication. High proliferation index (>14%) with Ki67 was noted in Luminal B, Basal and Hybrid types. 78% of the total 60 cases were alive and healthy. One death was reported in HER2, Hybrid and Basal types. The negative kappa value obtained while studying the agreement between the histopathological and molecular classication, indicates that the agreement is worse than chance and hence the importance of molecular classication is substantiated for the targeted therapy.