Comparison of the molecular profiling of core biopsy with surgical specimens in breast cancers and the effect of neoadjuvant therapy on the same - A North Indian study.

Abstract

The purpose of this study was to determine the concordance of core needle biopsy (CNB) and surgical specimens for determining the molecular profiling and to observe the changes in the same after neoadjuvant chemotherapy. This was a cross-sectional study over a period of one year on 95 cases. Immunohistochemical (IHC) staining was done as per the staining protocol in a fully automated BioGenex Xmatrx staining machine. On CNB, estrogen receptor (ER) positivity was seen in 58 out of 95 cases, comprising 61% of the total, and on mastectomy, it was positive in 43 (45%) cases. Progesterone receptor (PR) positivity was seen in 59 (62%) cases on CNB and 44 (46%) cases on mastectomy. Total 7 (7%) were human epidermal growth factor receptor 2 (HER2)/neu positive on CNB and 8 (8%) on mastectomy, respectively. There were 15 (15.7%) that showed discordant results after neoadjuvant therapy. Estrogen status changed from negative to positive in 1 (7%) case and positive to negative in 14 (93%) cases. Progesterone status changed from positive to negative in all 15 cases (100%). There was no change in the HER2/neu status. The agreement of hormone receptor status between CNB and subsequent mastectomy in the present study was found to be substantial (kappa value for ER, PR, and HER2neu as 0.608, 0.648, and 0.648, respectively. IHC is a cost-effective method to assess hormone receptor expression. This study shows that ER, PR, and HER2/neu expression in CNB should be reassessed in excision specimens for the better management of endocrine therapy.