Enumeration and Functional Analysis of Circulating Tumor Cells for Homologous Recombination: a Prospective Single-center Study on Advanced/Metastatic Solid Tumors

Inclusion Criteria: * Male or female patients ≥ 18 years at the day of signing informed consent. * Advanced/metastatic breast, prostate, ovarian and pancreatic cancer patients potentially eligible to PARP inhibitor treatment as monotherapy or in combination as per respective SmPC (see Appendix 1) or IB if the PARPi treatment is investigational. * Patients who have understood, dated, and signed the written voluntary informed consent form before undergoing any procedure specific to the protocol. * Patients affiliated with or benefiting from medical insurance. Exclusion Criteria: * Patients with secondary malignancy with the exception of basal or squamous cell carcinoma of the skin, in-situ carcinoma of the cervix, localized prostate cancer, prior malignancy and no evidence of recurrence for ≥ 2 years. * Patients presenting a psychological, familial, geographical, or social situation that, in the investigator's judgment, could potentially prevent the signing of informed consent and/or compliance with study procedures. * Pregnant or breast-feeding women. * Patients under judicial protection (guardianship, curatorship, or legal safeguard), adults under protection in accordance with Articles L.1121-6, L.1121-8, and L.1121-8-1 of the French Public Health Code, as well asindividuals not affiliated with a social security scheme or without equivalent health coverage.