Prediction of dose reductions and impact of reduced starting doses of CDK4/6i on effectiveness in HR-positive/HER2-negative metastatic breast cancer: Real-world data from the OPAL registry. 20. März 2026 Patrick Marschner, Kai Ringwald, Marc Thill, Mark-Oliver Zahn, Anja Welt, Arnd Nusch, Gabriele Kaltenecker, Yolanda Rodemer, Volker Hagen, Caroline Schock, Lisa Kruggel, Anja Kaiser-Osterhues, Dunja Klein, Nina Haug, Elmar Stickeler, Nadia Harbeck, Achim Wöckel, Norbert Marschner, Thomas Decker, the OPAL Registry Group Int J Cancer. 2026;1-13. doi:10.1002/ijc.70433 Abstract