Study Estimating Association Between Germline Mutations and PD-L1 Expression in Breast Cancer

This is a multicentre, non-interventional, prospective study to be carried out in representative oncology departments / institutions in order to determine the association between the presence of germline DNA-repair genes mutations and PD-L1 expression level in tumour and immune cells in breast cancer. No additional procedures besides those already used in the routine clinical practice will be applied to the patients.