"Observational, Retrospective and Prospective, Non-interventional, Multicentre on the Use of Genomic Testing in the Management of Early Stage HR+/HER2- Breast Cancer"

Inclusion Criteria: 1. . Age ≥ 18 years 2. PS ECOG 0-1 3. Histologically confirmed early breast carcinoma with positivity for hormone receptors (ER+ IHC \>10%) and HER2 negative (IHC value 0 1+ and/or FISH not-amplified) 4. Primary resective surgery for early breast cancer with adequate assessment of lymph node status (sentinel lymph node biopsy or complete axillary dissection), with one of the following diagnostic stages: * T1-3, N0, M0 * T1-3, pN1mic, M0 * T1-3, pN1a, M0 5. Indication for adjuvant treatment with endocrine therapy (ET) or chemo endocrine therapy (CET), according to the decision of the reference Breast Unit 6. Meeting the criteria for "intermediate" risk, i.e., no "low" or "high" risk of recurrence, as defined in the ministerial decree of 18/05/21: * Low risk defined by at least 5 of the following: G1, T1a-b, KI67 \< 15, N neg, ER \> 80% * High risk, defined by at least 4 of the following: G3, T \> 2, Ki67 \> 30, N pos, ER \< 30% 7. Indication for genomic test (Oncotype DX®, Mammaprint®, PAM50 Prosigna®, Breast Cancer Index®, EndoPredict®) by the Breast Unit 8. Ability to provide written informed consent to participate in the registry study, approved by the local Ethics Committee. 9. The patient underwent genomic testing starting from September 2021 Exclusion Criteria: 1. Low-risk and High-risk patients as defined in the Ministerial Decree of 18/05/21 2. ER negative and/or HER2 positive tumours 3. More than 3 lymph nodes involved at clinical/pathological staging 4. Invasive tumours \<2mm evaluated by local pathologists 5. Previous history of breast cancer 6. Synchronous breast cancers 7. Multifocal tumours 8. Metastatic disease 9. Contraindications to adjuvant treatments 10. Performance status (PS ECOG) \> 1 and / or other clinical factors that would make the patient a candidate and unsuitable for systemic adjuvant treatment or have received an exclusive indication for precautionary hormone therapy as part of the Breast Unit collegial assessment. 11. Psychiatric diagnosis that may affect the ability to participate in this study