Short-term Pre-OPerative Durvalumab (MEDI 4736) in Early Small Triple Negative Breast Cancer Patients (POP-Durva)

This study aims to evaluate the efficacy and safety of preoperative Durvalumab in patients with early small (cT1N0) triple negative breast cancer tumors. This study will recruit patients with early HR-negative breast cancer all invasive types (ER \=5%, eligible for a short-term treatment with Durvalumab. A total of 200 patients are planned to be enrolled in the study and which will receive 2 administrations of durvalumab 10mg/kg. After study treatment, patients: * In whom surgery is the first standard treatment strategy (i.e. after study treatment) no biopsy is required at the end-of-treatment visit. * In whom neo adjuvant therapy is the first standard treatment strategy (i.e. after study treatment) a breast ultrasound guided biopsy is mandatory at the EoT visit. If the biopsy-proven residual disease is demonstrated, patients will have the option to receive standard neoadjuvant therapy at the discretion of the treating investigator. Those with a complete response may proceed directly to surgery.