Abstract P1-17-09: Use of Oncotype DX ® testing in nodal positive breast cancer patients: Real-life data from a single center in Munich, Germany

Abstract

Abstract Introduction: Despite a large body of prospective studies showing good prognostic and predictive value of the Oncotype DX ® testing in ER+/HER2- early breast cancer patients after breast surgery, the test is currently not reimbursed in Germany by most national health insurance companies. Nevertheless, this multigene assay has been offered to node negative (N-) and increasingly to node positive (N1) patients with 1-3 positive lymph nodes by medical- and gyneco-oncologists for several years. The aim of the present study was to analyze real life data of the test in N1 patients from a German single center with special respect to the intermediate-risk recurrence score (RS) group and event-free survival (EFS). Patients and Methods: Patients with ER+/HER2- node positive breast cancer after breast surgery, to whom Oncotype DX ® testing was consecutively recommended by the interdisciplinary local tumor board from 1/2012 through 12/2016 at the Breast Center of the Red Cross Hospital Munich, Germany, were included in the study. Data was retrospectively retrieved from medical records (e.g. stage and histology), patient interviews as well as from the Munich Cancer Registry (outcome measurements). Patients were stratified according to Oncotype DX ® RS distribution (<11 low-risk, 11-25 intermediate risk and > 25 high-risk). Proportion of patients choosing adjuvant chemotherapy (CT) within the different RS groups and outcome were analyzed. Results: Oncotype DX ® testing was recommended and performed in 500 (17%) out of 2942 patients with ER+/HER2- tumors. Nodal status was positive in 159 (31.8%) of these patients. Patients with more than 3 positive lymph nodes and with missing data on follow-up were excluded, leaving 121 patients for the main analysis. According to RS distribution, n=19 (15.7%) were low-risk, n=83 (68.6%) intermediate-risk and n=19 (15.7%) high-risk, respectively. Although CT was generally discussed with all N1 patients with RS>10, only 39 patients (38.2%) of the intermediate and high-risk RS-group opted for systemic chemotherapy (24.1% of RS 11-25 and 100% of RS>25). In 13 of the patients (11%) within a median follow-up of 40 months an event occurred (4 loco-regional and 2 contralateral relapses, 5 distant metastases (3 bone, 2 visceral) and 2 deaths of other causes). Of those patients with events, three presented with RS <11, six with RS 11-25 and three with RS >25. In the intermediate group (n=83) EFS was 90% for patients receiving CT followed by endocrine therapy (ET) and 91.9% for patients with ET alone (p= 0,583). Conclusions: Using real life data from a large single breast center, only around 25% of patients with 1-3 positive lymph nodes from the intermediate RS group decided to undergo CT after Oncotype DX ® testing. The outcome of patients receiving ET only in this group was not inferior compared to CT followed by ET. Citation Format: Kriegmair A, Szeterlak N, Schrodi S, Stoetzer O, Pölcher M, Braun M. Use of Oncotype DX ® testing in nodal positive breast cancer patients: Real-life data from a single center in Munich, Germany [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 P1-17-09.