Neoadjuvant Therapy Study Guided by Drug Screening in Vitro Patient-derived Tumor-like Cell Clusters for Human Epidermal Growth Factor Receptor 2 (HER2) Negative Early Breast Cancer Patients

Neoadjuvant chemotherapy for breast cancer could make unresectable breast cancer be resectable and improve breast conservation rate. Patients with triple negative subtype who achieved pCR after neoadjuvant treatment would have longer survival. The neoadjuvant treatment for her2 negative patient was chemotherapy with combined drugs. However, not all patients benefit from chemotherapy but suffer from chemotherapy-related side effects. It was unknown for a patient who could benefit from which drug before chemotherapy. Drug sensitivity screening in vitro was a promising method for choosing chemotherapy. But there was no method could select effective drugs accurately for breast cancer participants until now.

Previously, investigators developed a patient-derived tumor-like cell clusters (PTC) in vitro culture technology. It is a cell cluster including tumor cells, mesenchymal cells and lymphocytes, which simulates the tumor microenvironment in vitro. In the preliminary exploration, investigators included 35 early breast cancer participants, the corresponding between in vitro drug sensitivity screening based on this technology and clinical treatment results was well. The results have been published.

This study will focus on her2 negative early breast cancer participants. 46 participants will be included. All of them will received in vitro drug sensitivity screening upon PTC before neoadjuvant therapy. The choice of chemotherapy drugs is determined based on the PTC drug sensitivity results. If single-agent chemotherapy is effective in vitro, this drug will be the chemotherapy regimen for the corresponding participants.