This study will recruit patients diagnosed with breast cancer who are candidates for neoadjuvant chemotherapy and subsequent surgery. Tumor tissue samples will be collected before and after treatment to establish patient-derived organoid cultures, which serve as personalized models of each patient's real tumor. Biomarkers released by the organoids (in particular those transported by extracellular vescicles) will be analyzed to identify predictors of therapeutic response. These biomarkers will be correlated with their expression in tumor tissue and subsequently validated in blood samples, collected pre, during and post treatment, as a non-invasive liquid biopsy approach. All data obtained will be analyzed by comparing patients who achieve a pathological complete response (pCR) with those who present residual disease after therapy (non-pCR).
