Study Evaluating DNA Double-strand Breaks (DSBs) REpair Factors (POLQ, Shieldin Complex and 53BP1) Expression as Biomarker of PARP Inhibitor Resistance in Patients With Deleterious Germline Mutation in BRCA 1/2 and HER2-negative, Metastatic or Locally Advanced Breast Cancer.

The purpose of this study is to assess whether expression of not only POLQ/Polθ, but also Shieldin complex and/or 53BP1 are correlated with primary and/or acquired resistance to PARPi (Poly(ADP-Ribose) Polymerases inhibitors) in a sub-population of locally advanced or metastatic breast cancer patients and vary regarding type and location of gBRCA1/2 mutations.

This translational research program is composed of two multicentric, non-randomized prospective studies in patients with HER2-negative locally advanced or metastatic breast cancer:

* The main study concerns 80 patients eligible for PARPi (according to the investigators).PARPi treatments (talazoparib or olaparib) will be administered and dosed according to the standard of care administration. * The sub-study concerns 40 patients in progression disease under PARPi alone.

For each included patient in the main study or sub-study, tumor biopsy specimen and blood samples will be collected at different times during the study.