This will be a retrospective analysis of patients with histologically confirmed triple-negative or HER2+ operable breast cancer (with high risk of recurrence) who are treated at Hellenic Cooperative Oncology Group (HeCOG)- affiliated departments of oncology. Patients who participate are 18 years or older, women of any menopausal status with triple-negative or HER2+ breast cancer who receive epirubicin and cyclophosphamide every two weeks followed by docetaxel every three weeks or weekly paclitaxel. Patients with HER2-positive tumors are treated with trastuzumab, initiated concurrently with the first cycle of docetaxel, for 52 weeks. Pertuzumab may be combined with trastuzumab only in patients with node-positive disease.Patients can be treated with hormone therapy and/or radiotherapy. The investigation of the potential biomarkers will be performed using in situ methods in Formalin fixed paraffin embedded (FFPE) tumor sections. More specific will be investigated the expression of estrogen and progesterone receptors, the expression of SPARC proteins, special cellular activation and metastasis systems and other important pathways in cell life and reproduction.
Statistical analysis: The primary endpoint of the study will be the progression-free survival (PFS), defined as the time from treatment initiation to either the first documented disease progression or death from any cause. Second primary endpoint will be the overall survival (OS), defined as the time from treatment initiation to patient's death or last contact. Survival curves will be estimated using the Kaplan-Meier method and compared across groups with the log-rank test. The associations between the clinicopathological factors to be examined and the mortality rate will be evaluated with hazard ratios estimated with Cox proportional hazards model. The statistical analyses will be completed using the SAS software (SAS for Windows, version 9.3, SAS Institute Inc., Cary, NC).
