Abstract P5-07-10: Progression-free survival (PFS) and overall survival (OS) in HER2-ve advanced breast cancer (ABC) patients (pts) according to the molecular subtype in the era of modern agents. Results from the GIM-13 AMBRA study

BACKGROUND Pts with ABC have a diverse clinical course and OS rates vary significantly among pts. New strategies had potentially changed the natural history of these pts, however data from clinical studies are still lacking and Real-World Studies (RWS) are crucial in clinical outcome evaluation. PATIENTS AND METHODS AMBRA is a longitudinal cohort study, aiming to describe the choice of first and subsequent lines of treatment in HER2-ve ABC pts receiving at least one CHT (SABCS 2016, P5-15-07 & P5-14-09) in the years 2012-2015. The present analysis is focused on the description of Progression-Free Survival (PFS) and OS according to the biologic subtype in the deceased population. So far, 791/1500 pts have been registered into the study and 255 (32.2%) are evaluable. Time to event analysis between subtypes was evaluated by Cox-Mantel Hazard Ratio and Logrank Test. DFS by Wilcoxon Rank-Sum Test RESULTS Pts distribution according to molecular subtype was: Luminal A (86, 33.7%), Luminal B (107 (42.1%), TNBC (62, 24.3%). Median ages at diagnosis were 55.8, 52.9 and 55.1 years for the 3 subgroups, respectively. Mean DFS was significantly different according to the molecular subtypes: 87.28, 61.37 and 23.9 months. The difference between Luminal B and TNBC is statistically significant as well. Mean PFS of 1st-line therapy was 17.9 11.7 and 7.8 months respectively. Mean OS from 1stprogression was 32.9 24.2 and 15.8 months respectively. CONCLUSIONS Our data confirm in a RWS the different biological behaviour between Lum A and B. Metastatic life span is quite good for Luminals and disappointing for TNBC. Median time from last CHT and Death is quite short and similar. Citation Format: Marina Elena Cazzaniga, Sabino De Placido, Alessia D9Alonzo, Michela Piezzo, Clara Natoli, Andrea Milani, Alessandra Bologna, Massimiliano Alu, Anna Turletti, Palma Pugliese, Laura Biganzoli, Claudia De Angelis, Ornella Garrone, Paolo Marchetti, Ferdinando Riccardi, Antonio Bernardo, Lorenzo Livi, Alessandra Fabi, Cristiana Taverniti, Emanuela Romagnoli, Paolo Pronzato, Giorgio Mustacchi, on behalf of GIM-13 AMBRA Study Group. Progression-free survival (PFS) and overall survival (OS) in HER2-ve advanced breast cancer (ABC) patients (pts) according to the molecular subtype in the era of modern agents. Results from the GIM-13 AMBRA study [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-07-10.