Influence of Neoadjuvant Chemotherapy on HER2/neu Status in Invasive Breast Cancer

Abstract

Neoadjuvant chemotherapy for breast carcinoma resulted in the HER2/neu status alteration by IHC, but they have stable gene amplification status by FISH. HER2/neu protein overexpression indicated greater sensitivity to neoadjuvant anthracycline- and taxane-based chemotherapy. Thus, retesting HER2/neu IHC status in residual tumors after NAC should be considered in order to optimize adjuvant systemic therapy.

Receptor Status Change From Primary to Residual Breast Cancer After Neoadjuvant Chemotherapy and Analysis of Survival Outcomes

“…Some studies that used IHC to measure HER2, HER2 status changed in 7.6% to 30.0% of tumors after NCT. 8,[18][19][20][21][22][23][24][25][26] A prospective study that used gene amplification to determine HER2 status found that up to 43% of trastuzumab-treated patients had tumors that had HER2 status discordance after NCT. 27 Similarly, we found that 45.7% of the trastuzumab-treated tumors became HER2-negative.…”

Change in HER2 status after neoadjuvant chemotherapy and the prognostic impact in patients with primary breast cancer

“…However, patients with a non‐pathologic complete response (non‐pCR) have poorer outcomes than those with a pathologic complete response (pCR) . Because trastuzumab is used in NAC setting, changes in the HER2 status of surgical specimens have been reported . However, the incidence of HER2 discordance between before (in needle biopsy specimens) and after chemotherapy (in surgical specimens), and the prognostic impact of such discordance remain unclear .…”

The importance of tissue confirmation of metastatic disease in patients with breast cancer: lesson from a brain metastasis case

“…Neoadjuvant therapy is mainly based on the immunohistochemical findings of the HR and HER2 status on the core needle biopsy. With the growing use of neoadjuvant therapy, it is important to know whether it modulates the biological behaviors of breast cancer cells [3, 23, 24]. …”