Abstract OT1-12-03: RESCUE: Reaching for Evidence-baSed Chemotherapy Use in Endocrine sensitive breast cancer - A prospective health care study on risk assessment by the clinicomolecular test EndoPredict®and long-term patient outcome in early luminal breast cancer

Background: In node negative and 1-3 positive nodes breast cancer patients with hormone receptor positive (HR+), HER2-negative (HER2-) early-stage breast cancer the indication for chemotherapy is based on clinical and pathologic risk stratification (tumor size, nodal status, grading, quantitative ER, progesterone receptor and Ki67). For further decision-making, the EndoPredict test, which combines a molecular signature with the clinical risk factors tumor size and nodal status, stratifies patients into “low risk" or “high risk” groups. Level I-B- evidence demonstrates, that EndoPredict predicts the 10 year cumulative risk of relapse and metastases in patients with HR+/HER2- primary breast cancer with endocrine treatment. Aim: In the RESCUE-Trial we document distant metastasis-free survival (DMFS), disease free survival (DFS) and overall survival (OS) events in patients who had an EndoPredict test. The primary objective is to show that 10-year DMFS of patients tested as “low risk” by EndoPredict and treated with adjuvant endocrine therapy alone is >90 %. Secondary endpoints among others include DMFS, DFS, OS in patients with EPclin “low risk” versus “high risk”. Also the proportion of patients whose treatment was concordant and non-concordant with EndoPredict test results, will be analyzed for survival. The prognostic performance of classical prognostic factors (like tumor size, nodal status, grading, quantitative ER, progesterone receptor and Ki67 level) with respect to survival will also be assessed. Eligibility: Patient with HR+/HER2- primary invasive breast cancer stage I/II and T1 to T3 with 0 to 3 positive lymph nodes will be eligible, if they had an EndoPredict test within three months before inclusion. Methods: The EndoPredict test results, tumor board decision and anti-tumor therapy will be assessed. After one year, annually (for 10 years), patients will be evaluated for treatment compliance, recurrence, metastases, and survival. The primary endpoint will be analyzed by a Kaplan-Meyer estimate for which a one-sided lower 95 % confidence interval will be given. Several secondary endpoints will be assessed in three interim analyses after completion of the 1st, 3rd, 5th year and then finally after 10 years. Accrual: Start of accrual is planned for July 2018. At least 26 sites in Germany and one site in Switzerland will be active. Sponsor: The study is sponsored by the North-Eastern-German Society of Gynecological Oncology (NOGGO) e.V. Contact Information: For further information, contact NOGGO via studies@noggo.de or the leading physician Dr. Johannes Ettl via johannes.ettl@tum.de. Citation Format: Ettl J, Blohmer J-U, Denkert C, Keller M, Klein E, Kronenwett R, Neuser P, Paepke S, Schade-Brittinger C, Schnuppe K, Untch M, Wittenberg M, Kiechle M. RESCUE: Reaching for Evidence-baSed Chemotherapy Use in Endocrine sensitive breast cancer - A prospective health care study on risk assessment by the clinicomolecular test EndoPredict® and long-term patient outcome in early luminal breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-12-03.