The Cancer Genome Atlas (TCGA) has recently characterized four distinct molecular subgroups of endometrial cancer phenotypes. Carien Creutzberg, MD, PhD, of the Leiden University Medical Center, Leiden, Netherlands explains the implications and the latest PORTEC trial (NCT03469674) that aims to further define these subgroups in clinically meaningful ways. This interview was recorded at the European Society for Medical Oncology (ESMO) 2018 Congress, in Munich, Germany.