Endometrial Cancer Vaginal Fluid Specimen Collection Study

Inclusion Criteria Cohort 1 Participants: * Age ≥ 45 years, OR age ≥ 18 years with at least one risk factor * Diagnosed with abnormal uterine bleeding (AUB) * Planning standard-of-care endometrial tissue sampling to assess for endometrial cancer (EC) or atypical endometrial hyperplasia/endometrial intraepithelial neoplasia (AEH/EIN) Cohort 2 Participants: * Age ≥ 18 years * Newly diagnosed, biopsy-confirmed EC or AEH/EIN * Planning initial management for their endometrial pathology Exclusion Criteria * Prior partial or complete hysterectomy * Current pregnancy * Prior pelvic or vaginal radiotherapy * Chemotherapy within past 5 years (except tamoxifen) * Any condition judged by the Investigator to preclude participation Additional for Cohort 1: * Cancer diagnosis within past 5 years (except non-gynecologic skin cancer) * Current biopsy-proven cervical, vaginal, or vulvar cancer, or lower genital tract dysplasia * Current biopsy-proven endometrial cancer, hyperplasia, or benign polyp * Benign endometrial biopsy within last month Additional for Cohort 2: * Cancer diagnosis other than EC within past 5 years (except non-gynecologic skin cancer) * Prior cervical cancer or biopsy-proven cervical dysplasia * Surgery for recurrent EC * Preoperative neoadjuvant chemotherapy or radiotherapy for current EC * Prior treatment or surgery to remove target pathology during current episode