Abstract PS7-46: Enrollment of older metastatic breast cancer patients in clinical trials

Background: About 40% of breast cancer cases occur in women 65 years old (yo) or older and 20% in women over 75 yo. These numbers are expected to increase in the near future. Ironically, older patients remain underrepresented in clinical trials with no improvement in the past decade, although they may present different efficacy/toxicity profiles compared with younger adults. In this context, real life cohorts may bring valuable insight to identify potential barriers to recruitment of older patients with metastatic breast cancer (MBC) in clinical trials. Methods: We used the national Epidemio-Strategy and Medical Economics (ESME) MBC Data Platform, a multi-center real life database using a retrospective data collection process in 18 French Cancer Centers. Cases selected were adult patients with MBC whose first metastasis was treated between January 1st, 2008 and December 31st, 2016. We selected MBC women over 70 yo at the time of MBC diagnosis, with at least one line of systemic treatment and no other cancer in the 5 years before MBC. The primary objective was to describe factors associated with enrollment in clinical trials in older patients, using a multivariable Cox model. Factors included in this model were age (continuous, and by class), period (2008-2011 vs 2012-2016), phenotype (ER+, HER2+, or ER- HER2-), ECOG Performance Status (PS), treatment, metastatic sites (brain, visceral, nodes/bone only) and number, and volume of hospital activity. No geriatric description could be extracted from the database. Results: There were 5846 patients ≥70yo (median age 77) and 15892 patients By multivariate analysis, participation of older patients to a clinical trial was associated with an increased OS (HR 0.7; 95% CI 0.6-0.8) but not with a better breast cancer specific survival (HR 0.94; 95%CI 0.68-1.29). Conclusions: In this large real-life database, few older MBC patients were enrolled in a trial compared with younger ones. Factors associated with such participation to clinical research were younger age ( Citation Format: Michael Bringuier, Matthieu Carton, Christelle Levy, Anne Patsouris, David Pasquier, Marc Debled, Olivier Rigal, William Jacot, Anthony Goncalves, Isabelle Desmoulins, Thibault De La Motte Rouge, Thomas Bachelot, Jean-Marc Ferrero, Jean-Christophe Eymard, Florence Dalenc, Marie-Ange Mouret-Reynier, Thierry Petit, Michael Chevrot, Coralie Courtinard, Lionel Uwer, Jean-Sebastien Frenel, Capucine Baldini. Enrollment of older metastatic breast cancer patients in clinical trials [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-46.