Real-World Data on Pathological Response and Survival Outcomes After Neoadjuvant Chemotherapy in HER2-Low Breast Cancer Patients.

BACKGROUND: Data on the pathological responses and survival outcomes after neoadjuvant chemotherapy (NACT) in human epidermal growth factor receptor-2 (HER2)-low breast cancer (BC) are lacking. This study aims to investigate this topic in the real world. METHODS: Clinicopathological data from 819 HER2-negative BC patients who underwent NACT between 2010 and 2020 were retrospectively retrieved from the Shanghai Jiaotong University Breast Cancer Database. These patients were categorized into HER2-low and HER2-0 groups. Logistic analyses were conducted to identify predictors of complete pathological response (pCR) and breast pCR. Cox regression analyses were conducted to assess the factors associated with disease-free survival (DFS) and overall survival (OS). Kaplan-Meier (K-M) curves were generated to compare DFS and OS between HER2-low BC and HER2-0 BC. RESULTS: Of the 819 BC patients, 669 (81.7%) had HER2-low tumors, and 150 (18.3%) had HER2-0 tumors. HER2-low BC had a significantly higher ratio of ER ≥ 10%, PR ≥ 20%, and Ki67 ≥ 15% than HER2-0 BC. A significantly higher breast pCR rate was observed in HER2-low BC than in HER2-0 BC (13.6% and 7.3%, respectively, P = .036). Age, HER2 status (low or 0), Ki67, and surgery options were associated with breast pCR in HER2-negative BC. In HER2-low BC, the pCR rate of ER ≥ 10% BC was significantly lower than that of ER < 10% BC, but the DFS and OS of ER 10% BC were significantly higher. The K-M curve showed no significant differences in DFS or OS between HER2-low and HER2-0 BC. Cox regression revealed that ER expression and histological grade (III vs. I∼II) were significantly associated with survival in HER2-low BC. CONCLUSIONS: In this real-world data (RWD) study, a significantly higher breast pCR rate was found in HER2-low BC than in HER2-0 BC, although there was no significant difference in survival. Moreover, ER expression had a significant prognostic impact on HER2-low BC.

Breast cancer organoids and their applications for precision cancer immunotherapy.

Immunotherapy is garnering increasing attention as a therapeutic strategy for breast cancer (BC); however, the application of precise immunotherapy in BC has not been fully studied. Further studies on BC immunotherapy have a growing demand for preclinical models that reliably recapitulate the composition and function of the tumor microenvironment (TME) of BC. However, the classic two-dimensional in vitro and animal in vivo models inadequately recapitulate the intricate TME of the original tumor. Organoid models which allow the regular culture of primitive human tumor tissue are increasingly reported that they can incorporate immune components. Therefore, organoid platforms can be used to replicate the BC-TME to achieve the immunotherapeutic reaction modeling and facilitate relevant preclinical trial. In this study, we have investigated different organoid culture methods for BC-TME modeling and their applications for precision immunotherapy in BC.