Basal Marker Reactivity in Triple Negative Breast Carcinomas Does Not Predict Pathologic Complete Response Following Neoadjuvant Chemotherapy.
James A Kraus, Sushil Beriwal, David J Dabbs, Rohit Bhargava. Magee-Womens Hospital of UPMC, Pittsburgh, PA
Background: Neoadjuvant chemotherapy (NACT) has assumed an increasingly prominent role in the management of breast cancer. Pathologic complete response (pCR) following NACT is most commonly achieved in hormone receptor negative breast carcinomas, including “triple negative” and “ERBB2” tumors. The objective of this study is to assess the value of “basal-like” immunohistochemical (IHC) markers in predicting pCR following NACT in triple negative breast carcinomas.
Design: From 2008 to 2010, consecutive cases of triple negative breast carcinoma treated with NACT were identified in the pathology database at our institution. Sixty-three of these cases had at least one basal marker IHC result. Percent tumor volume reduction following NACT and IHC results for CK5 (or CK5/6), CK14, CK17 and EGFR were obtained from pathology reports. Any reactivity was considered a positive result as per the British Columbia group criteria. pCR was defined as absence of invasive carcinoma in the breast and regional lymph nodes following NACT.
Results: The overall rate of pCR was 28% (28 of 101). Eighty-nine percent (17 of 19) of tumors with pCR were positive for CK5 (compared to ninety percent [36 of 40] of those without pCR; p = 1.00).
|CK5 Positive||CK5 Negative||Total|
|Tumors with pCR||4||39||43|
|Tumors without pCR||2||18||20|
|EGFR Positive||EGFR Negative||Total|
|Tumors with pCR||3||35||38|
|Tumors without pCR||3||17||20|