Invasive Ductal Carcinoma Breast: How Neoadjuvant Chemotherapy Affects the Status of Estrogen Receptor, Progesterone Receptor and HER2/Neu-A Tertiary Care Centre Study

Introduction: Determination of Estrogen Receptor (ER), Progesterone Receptor (PR) and HER2/neu in primary Invasive Ductal Carcinoma (IDC) breast is the standard of care parameter for determining treatment options. Whether or not Neoadjuvant Chemotherapy (NAC) affects the receptor status is still an unanswered question. Aim: To compare immunohistochemical (IHC) profiles of ER, PR and HER2/neu in primary IDC breast before and after NAC to assess the subsequent effects on receptor status. Materials and Methods: Thirty two patients diagnosed with primary IDC breast who had a previous breast core biopsy with complete IHC profile followed by NAC and Modified Radical Mastectomy (MRM) were included. For each case demographic and histologic data was collected, including age, grade, amount of necrosis post NAC and IHC panel for ER, PR and HER2/ neu in core biopsies. The same IHC panel was applied on Post NAC MRM specimen. Pre- and post NAC IHC expression was compared. Results: Patients ranged from 30 years to 75 years in range. ER, PR and HER2/neu status of core biopsies and MRM specimen were compared and overall agreement was noted. Comparison for each receptor was done using McNemar’s test and significance was calculated. There was no statistically significant difference in ER and Her2/neu expression between pre- and post-NAC specimens. However, a statistically significant loss of PR expression was noted between the two groups. Conclusion: Accurate determination of ER, PR and Her2/ neu status in primary IDC breast is important to guide further treatment. Change in receptor status post NAC may warrant corresponding change in hormonal therapy.