The aim of this study is to establish organoid cultures, which are three-dimensional in vitro tumor models capable of supporting the long-term ex vivo growth of tumor cells derived from patients with breast carcinoma. These organoids will be used for the isolation of extracellular vesicles (EVs), which are naturally released by cells and have the ability to selectively recognize tumor tissue. Due to these properties, EVs represent promising vectors for the targeted delivery of diagnostic agents, with potential applications in fluorescence-guided surgery.

Breast cancer is the leading cause of cancer-related mortality among European women. Despite advances in diagnosis and treatment, disease recurrence and therapy resistance remain major challenges. Improving the specific visualization of tumor tissue is essential to support precision medicine approaches and enable more accurate surgical resections.

Extracellular vesicles (EVs), naturally released by cells, have shown the ability to selectively recognize tumor tissue and represent promising vectors for targeted delivery of diagnostic agents. However, their clinical application is currently limited by the lack of reliable and representative sources. This project proposes the use of patient-derived organoids (PDOs) as a controlled and patient-specific source of EVs to better study their biological functions and diagnostic potential.

PDOs are accurate and personalized three-dimensional tumor models that recapitulate the biological and clinical characteristics of individual breast cancers. Differences between tumor-derived and healthy tissue samples will also be explored.

This prospective, single-center, observational study will recruit breast cancer patients undergoing surgery at IRCCS ICS Maugeri (Pavia). Clinical and pathological data will be collected prospectively, along with a 5-year follow-up to monitor disease recurrence and treatments. Organoids will be generated from surgical specimens to isolate EVs, which will be investigated as delivery systems for indocyanine green fluorescent contrast agents in FGS applications. No additional clinical procedures or blood samples beyond standard care are required.

Inclusion Criteria:

• Female subjects;
• Confirmed diagnosis of breast heteroplasia
• Age >= 18 years;
• Patients willing to follow the usual oncological follow-up;
• Patients with de novo metastatic disease (M+), receiving primary chemotherapy, if candidates for primary tumor biopsy;
• Subjects who agree to participate in the study by signing and dating the Informed Consent form.

Exclusion Criteria:

• Patients without a proven cyto-histological diagnosis of breast carcinoma;
• Subjects affected by other solid tumors besides the breast lesion.

All patients consecutively referred to the Breast Unit of the IRCCS ICS Maugeri in Pavia who have breast neoplasm will be included in the study.