Effectiveness outcomes by treatment-free interval among patients receiving palbociclib plus endocrine therapy in HR+/HER2- advanced breast cancer in the real- world setting: Results from the PERFORM study. 14. September 2026 R. Bartsch, M. Korell, G. Pfeiler, T. Gabrysiak, T. Fietz, M. Deryal, V. Petersen, T. Resch, B. Schöttker, T. Decker, L. Müller, J. Radosa, U. Rhein, M. Glasstetter, D. Klein, A. Buder, H. Kruger, A. Quartier, J. Dzieran, M.P. Lux. J Clin Oncol 44, 1061-1061(2026). DOI:10.1200/JCO.2026.44.16_suppl.1061 Abstract Poster