Patient-derived Xenograft (PDX) Modeling of Treatment Response for Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) represents an aggressive, genomically heterogeneous, subtype of breast cancer with limited therapeutic options. Many patients with TNBC receive standard neoadjuvant chemotherapy (NAC) pre-operatively; response is directly correlated with long-term outcome. Patients with residual disease after NAC are at higher risk for recurrent or metastatic disease, but additional adjuvant therapies are not currently part of standard care. Personalized treatment for patients with TNBC requires an improved understanding of the genomic landscape of individual TN breast tumors, as well as improved predictive models of response to specific therapeutic agents. This pilot study will determine if patient-derived tumor xenograft (PDX) mouse models can serve as a reliable model for treatment response for individual patients with TNBC. The tumor tissue collected (paired pre-and post NAC) will also provide insight into mechanisms of therapeutic resistance for individual patients. This study will enhance our understanding of the genomic basis for treatment response for TNBC on an individual patient basis, and lead to potential new therapeutic options for high-risk TNBC patients with post-NAC residual disease. Objectives: 1. To collect and bank tissue specimens from patients with operable triple negative breast cancer at: a) at time of diagnosis, prior to the start of neoadjuvant therapy and b) at time of definitive surgery, after the completion of neoadjuvant therapy. 2. To collect and bank tissue specimen for patients with advanced metastatic triple negative disease prior to start of any line therapy for metastatic disease. 3. To create patient-derived xenograft (PDX) mouse models utilizing specimens collected pre- and post- neoadjuvant treatment 4. To determine if response of PDX tumors to cytotoxic agents in the Champions Oncology Tumor GraftTM (COTG) assay correlates with responses observed in patients. 5. To perform genomic analyses of patient tumor specimens collected pre- and post neoadjuvant treatment to study mechanisms of drug resistance