EFFECT OF NEOADJUVANT CHEMOTHERAPY ON HORMONE RECEPTOR (ER, PR) STATUS AND HER-2/NEU EXPRESSION IN INDIAN BREAST CANCER PATIENTS: A PROSPECTIVE STUDY

Objective: This study was aimed to evaluate whether neoadjuvant chemotherapy (NACT) changes hormone receptor (ER, PR) status, Her-2/neu expression in carcinoma breast and role of outcome in planning adjuvant chemotherapy. Methods: 71 patients of locally advanced breast cancer (LABC), receiving NACT, were included. Core biopsy was done, to confirm invasive cancer, ER, PR and Her-2/neu expression before commencing NACT. Post treatment mastectomy specimen was analyzed for histopathology, ER, PR and Her-2/neu expression. Results: Immunohistochemistry (IHC) showed that ER positivity changed from 29.6% (n=21) to 28.2% (n=20) after treatment. While 70.4% (n=50) were ER- before treatment which increased to 71.8% (n=51) post chemotherapy (p=0.99). Pre-NACT, PR was positive in 31.0% (n=22) which changed to 28.2% (n=20) after treatment. 69% (n=49) were PR before treatment which increased to 71.8% (n=51) post chemotherapy (p=0.99). Her-2/neu was positive in 71.8% (n=51) before treatment which became 70.4% (n=50) post-treatment (P= 0.88). 26.8% were ER+ PR+ (n=19), 66.2% were ER-PR- (n=47), 4.2% were ER-PR+ (n=2) before NACT. Change in expression of hormone receptor status was noticed, ER+PR+ decreased to 25.4% (n=18), ER-PR- increased to 69.0% (n=49), ER-PR + decreased to 2.8% (n=2), no change was noticed in ER+PR- status. Tumor size was significantly reduced from pretreatment (39.37? 10.63 cms) to post-treatment (23.87?7.51 cms) (p < 0.05). Conclusion: On the basis of this study it was concluded that ER, PR and Her-2/neu status changes on IHC staining after NACT. So, IHC analysis on a post treatment tissue block should be repeated before planning adjuvant chemotherapy in patients of carcinoma breast.