Influence of neoadjuvant chemotherapy on HER2/neu status in invasive breast cancer.

Reliably estimating HER2/neu expression in breast cancer is important for predicting patient prognosis and optimizing adjuvant therapeutic strategies. In this retrospective cohort study, effects of NAC on HER2/neu status in invasive breast cancer were evaluated, and the related factors were analyzed. One hundred thirty-one patients with primary breast cancer were treated with anthracycline- and/or taxane-based NAC. HER2/neu status was evaluated by IHC on core needle biopsies of primary tumors before NAC and surgical resection specimens of post-NAC residual breast cancers or tumor-positive axillary lymph nodes. Thirty-two pairs of specimens with discordant HER2/neu IHC scores were analyzed by fluorescence in situ hybridization (FISH). A significant difference in HER2/neu status by IHC between core needle biopsies and surgical resection specimens in patients receiving NAC was observed. After NAC, 23.4% (29 of 124) of tumors showed downregulated HER2/neu expression by IHC. Alterations of HER2/neu IHC scores did not significantly correlate with tumor subtype, pathologic response to NAC, adjuvant regimen, or time interval from the last chemotherapy to surgery. HER2/neu protein overexpression level was associated with favorable pathologic response to anthracycline and taxane-based chemotherapy. However, tumors with altered HER2/neu IHC scores after NAC revealed stable HER2/neu gene amplification/nonamplification by FISH analysis. 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.

Li P ，Liu T ，Wang Y ，Shao S ，Zhang W ，Lv Y ，Yi J ，Wang Z ... -  《-》

Impact of Neoadjuvant Chemotherapy on Breast Cancer Subtype: Does Subtype Change and, if so, How? : IHC Profile and Neoadjuvant Chemotherapy.

De La Cruz LM ，Harhay MO ，Zhang P ，Ugras S ... -  《-》

MRI staging after neoadjuvant chemotherapy for breast cancer: does tumor biology affect accuracy?

McGuire KP ，Toro-Burguete J ，Dang H ，Young J ，Soran A ，Zuley M ，Bhargava R ，Bonaventura M ，Johnson R ，Ahrendt G ... -  《-》

Comparison of different approaches for assessment of HER2 expression on protein and mRNA level: prediction of chemotherapy response in the neoadjuvant GeparTrio trial (NCT00544765).

Noske A ，Loibl S ，Darb-Esfahani S ，Roller M ，Kronenwett R ，Müller BM ，Steffen J ，von Toerne C ，Wirtz R ，Baumann I ，Hoffmann G ，Heinrich G ，Grasshoff ST ，Ulmer HU ，Denkert C ，von Minckwitz G ... -  《-》

HER2 status in patients with breast carcinoma is not modified selectively by preoperative chemotherapy and is stable during the metastatic process.

The objective of this study was to determine whether HER2 expression levels in breast carcinomas were modified by chemotherapy or during the metastatic process. HER2 expression was analyzed on sequential tissue specimens taken from the primary tumor before patients received preoperative chemotherapy (CT) and from post-CT residual breast tumor or at a metastatic site. The first group of patients included 59 women who presented with T2-T4,N1-N2 breast carcinoma and were treated by preoperative anthracycline-based CT and then underwent surgery. The second group included 44 patients with metastatic breast carcinoma localized to the lung (27 patients) or to the liver (17 patients). HER2 status was determined by immunohistochemistry using an anti-p185(HER/neu) monoclonal antibody and was classified as overexpressed or not overexpressed. Among the patients who received preoperative CT, HER2 overexpression was observed in 15 of 59 patients (25%). A complete pathologic response was observed in 2 of these 15 patients. HER2 still was overexpressed in 11 of 13 remaining residual tumors and was no longer detectable in 2 tumors. In addition, the 29 tumors with no HER2 overexpression before CT remained negative after treatment. In patients with metastatic breast carcinoma, HER2 was overexpressed in 11 of 44 primary tumors (25%). In 9 of these 11 tumors, HER2 overexpression was maintained in the metastases (9 pulmonary metastases and 4 hepatic metastases). In two patients who had low levels of HER2 overexpression in their primary tumors, no staining was observed in the secondary tumor (one pulmonary tumor and one liver tumor). There were no tumors in which the overexpression of HER2 was found only in the metastasis. The current study showed that, in most patients, HER2 overexpression was unchanged after CT and in metastatic sites. No HER2 negative primary tumors became HER2 positive after patients received CT or during the metastatic process. In a few patients, a diminution in the level of HER2 expression was observed after CT or in secondary tumors. This may have been due to a transitory state of altered tumor cells or to the selection of HER2 negative tumor cells clones.

Vincent-Salomon A ，Jouve M ，Genin P ，Fréneaux P ，Sigal-Zafrani B ，Caly M ，Beuzeboc P ，Pouillart P ，Sastre-Garau X ... -  《CANCER》