PET Dynamics to Response-Adapted Neoadjuvant Therapy in TNBC

Eligible patients with stage 2 and 3 triple negative breast cancer will be treated with 4 cycles of neoadjuvant paclitaxel/carboplatin/pembrolizumab. A PET scan will be performed at baseline and after 1 cycle of therapy. A breast MRI will be performed after treatment completion. Patients with complete clinical response will proceed to surgery. Patients with clinical residual disease will complete neoadjuvant rescue with 4 cycles of doxorubicin/cyclophosphamide prior to surgery. If residual disease identified after surgery, adjuvant therapy to be determined by the treating oncologist (may include doxorubicin/cyclophosphamide/pembrolizumab, capecitabine etc).

Inclusion Criteria: 1. Stage II-III TNBC - estrogen receptor (ER) and progesterone receptor (PR) up to and including 10% is eligible 2. Age ≥ 18 years 3. Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2 4. Eligible for standard chemo-immunotherapy as determined by treating physician, including consideration of: 1. Adequate marrow and organ function 2. Co-morbid conditions do not preclude the use of chemo-immunotherapy (such as uncontrolled autoimmune disease, or the use of immunosuppressive medications) 5. Patients must have the ability to understand and the willingness to sign a written informed consent prior to registration on study Exclusion Criteria: 1. Patients unable to undergo PET or MRI 2. Evidence of metastatic disease or loco-regional recurrence (i.e. distant or chest wall recurrence) 3. Inflammatory breast cancer 4. Previous treatment with paclitaxel, carboplatin, or immune checkpoint inhibitors