This study is being done in order to find out if this new approach is better or worse than the usual approach for early-stage endometrial cancer. The usual approach is defined as the care most people get for early-stage endometrial cancer.~The usual approach for patients who are not in a study is treatment with surgery. Tissue that is removed as part of this procedure is analyzed in the pathology laboratory to guide the doctor to decide whether or not additional treatment such as radiation and or chemotherapy should be recommended.
This protocol tests de-escalated adjuvant treatment in patients with POLE-mutated or p53wt/NSMP (p53 wildtype/no specific molecular profile) early-stage endometrial cancer (EC). Patients may be enrolled in one of two sub-studies~EN10.A/RAINBO BLUE: POLE-mutated EC~EN10.B/TAPER: p53 wildtype / NSMP EC