Reaching for Evidence-baSed Chemotherapy Use in Endocrine Sensitive Breast Cancer

The goal of the study is to receive current and comprehensive information about the diseasefree (remote metastasis free and recurrence free) interval of EndoPredict® low risk patients. The study is organized and managed by the NOGGO e.V. (North Eastern German Society of Gynaecological Oncology e.V.) study coordination office under the existing and efficient infrastructure. All patients who receive gene expression analysis with EndoPredict® and satisfy the remaining inclusion / exclusion criteria may participate in the study. Data collection is prospective and non-interventional. The recruitment of the required patients is expected to take a maximum of 36 months . It must be emphasized that the study is data collection only and not an interventional study. This means that the choice and implementation of the therapy as well as the treatment assessments and frequency during and after the treatment can only be determined by the Investigator. The decision to participate in the study is independent of the patient´s therapy within the framework of a study. Patient data will be recorded at the time of inclusion and once a year thereafter. Patient follow-up will be by phone from the second year onward. Primary objective is to show that female patients who have been tested as "low risk" by EPclin and have been treated with endocrine therapy only for at least 5 years have a 10-year DMFS rate \> 90% (lower boundary of the one-sided 95% confidence interval). Secondary objectives comprise the evaluation of DMFS (distant metastasis free survival) , DFS (disease free survival) and OS (overall survival) rates at different time points and for different groups. Assessment of the given chemotherapy regimens and the given endocrine therapy will be performed and the proportions of patients will be determined with respect to the received treatment and its duration in different groups. Furthermore, the proportion of patients in whom the tumor board recommendation follows the EndoPredict® result and the proportion of patients actually treated according to EndoPredict® result will be determined. The association between outcome and treatment, EPclin, EP, and classical prognostic factors will be investigated in different groups of patients. The correlation and concordance between EPclin calculations derived from biopsies and surgical specimens will be assessed.