Abstract OT3-3-02: ASTER 70s UNICANCER phase III trial: Can a genomic prognosticator help tailoring adjuvant systemic treatment for luminal breast carcinoma in elderly women?

The benefit of adjuvant chemotherapy (CT) added to hormonal therapy (HT) compared with HT alone remains debated for women >70 with ER+ HER2- breast cancer (BC). Selection of valid indications might be improved by the use of better prognosticator. This trial compares the impact of both strategies on overall survival (OS) according to Genomic Grade (GG). Following surgery, ∼2,000 patients (Pts) will have a GG performed centrally on FFPE specimens by RT-PCR. Those with a high risk (high or equivocal GG) will be randomized to HT alone vs CT+HT. Pts with a low GG will be followed as an observational cohort. OS (all deaths) is the primary endpoint. Secondary objectives include competing events, cost-effectiveness and Q-TWiST analysis, geriatric dimension, willingness and health-related quality of life including specific ELD15. Translational research will focus on prognostic biomarkers and pharmacogenetics. Statistical design: sample size based on 4-year OS benefit favouring CT (87.5 vs 80%; HR 0.60); bilateral test α=0.05, β=0.20; 129 events expected in 700 randomized Pts enrolled over 4 years. From 04/12-05/14, 67 centres in France and Belgium have included 990 Pts aged 70-92. Only 31 GG evaluations were not performed (tumour blocks not available, 14; consent withdrawal or central pathology review discordance, 7 each; treatment choice, 3). In the main recruiting site, the study was not proposed to 20% of pre-screened Pts mostly because of team choice (50%) and inclusion criteria (25%). Amongst those informed, 66% accepted to participate. Median time to get GG information was 17 days (11-25) from sending tumour sample to providing the information to patient. Of 932 cases with GG report, 374 (40%), 187 (20%) and 362 (39%) were low, equivocal and high GG respectively; 9 tests (1%) failed for technical reasons. The proportion of high-risk tumours (high/equivocal GG 59%) is similar to that observed in general BC populations (40% to 60%) and only 21 of high-risk cases were not randomized (consent withdrawal, 6; treatment choice, 5; laboratory values, 4; tumour phenotype not confirmed or distant metastasis, 3 each). With 75% of target recruitment in Citation Format: Coraline Dubot, Emmanuelle Bourbouloux, Olivier Mir, Sylvie Kirscher, Olivier Rigal, Jean-Marc Ferrero, Herve Cure, Emmanuel Blot, Djelila Allouache, Paul Cottu, Gilles Romieu, Claudia Lefeuvre, Emmanuelle Malaurie, Nicole Tubiana-Mathieu, Magali Lacroix-Triki, Florence Rollot, Helene Peyro-Saint-Paul, Christine Orsini, Franck Bonnetain, Etienne Brain. ASTER 70s UNICANCER phase III trial: Can a genomic prognosticator help tailoring adjuvant systemic treatment for luminal breast carcinoma in elderly women? [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr OT3-3-02.