Molecular and ctDNA Characterization of High-Risk Endometrial Cancer

Inclusion Criteria: * Age ≥ 18 years * Planned complete surgical staging at Mayo Clinic. Complete surgical staging includes at least total hysterectomy, bilateral salpingo-oophorectomy and lymph node assessment. Sentinel node mapping meets the criteria for lymph node assessment. Peritoneal cytology is recommended. Additional staging procedures such as pelvic and para-aortic nodal evaluation, omental biopsy or omentectomy, may also be utilized for staging in patients based on the clinical situation and at the surgeon's discretion * At least one preoperative or postoperative feature of aggressive disease \[International Federation of Gynecology and Obstetrics (FIGO) staging used throughout this protocol\] * Preoperatively: * Biopsy with grade 3 endometrioid endometrial cancer (EC) or non-endometrioid EC * Patients with FIGO grade 1-2 EC with evidence of extrauterine disease on imaging (CT, MRI, or PET) * Postoperatively: * Endometrial cancer (FIGO) with one or more established risk factors: * Non-endometrioid histology * Grade 3 * Lymphovascular space invasion (LVSI), ≥ 50% of myometrial invasion, presence of isolated tumor cells (ITC) in a sentinel lymph node OR * Stage II to IV (FIGO) EC * Provide written informed consent * Willingness to provide mandatory blood specimens for correlative research * Willingness to provide mandatory tissue specimens for correlative research * Willingness to return to registering site for clinical follow-up Exclusion Criteria: * Patient receiving or who has received neoadjuvant chemotherapy * Pre-operative pregnancy