BACKGROUND: Endometrial cancer is a common and deadly cancer for women. It is getting more common and deadly because risk factors like age and obesity are increasing. Also, this cancer is becoming more common and deadly for black women than white women. Researchers want to find better ways to take samples and test them for this cancer. They want to study this for a racially diverse population. One way to take samples might be from a tampon. If identified early, endometrial cancer can be highly curable; however, the earliest stages may be asymptomatic, and clinical symptoms are often missed. Combining sensitive molecular testing approaches with non-invasive sampling techniques may to lead to the development of novel endometrial cancer early detection approaches with the potential to overcome disparities in access to care and time to diagnosis and treatment. In contrast to endometrial cancer, ovarian cancer is typically detected at advanced stages with poor survival since symptoms manifest only late in the disease process and are very unspecific. Racial disparities in ovarian cancer incidence and mortality are also much less pronounced. Racial disparities can manifest particularly when screening, symptom appraisal and early detection, and effective treatment interventions have important roles in determining outcomes of cancers. OBJECTIVES: The purpose of this study is to see if it is possible and acceptable for individuals to have an endometrial or ovarian sample collected by using a tampon placed in the vagina. The investigators will look at DNA in these samples. DNA is the genetic information participants inherited from their parents. The investigators want to see whether the investigators can find changes in DNA and proteins related to endometrial or ovarian cancer from tampon samples. Tests on the samples from tampons will help to understand endometrial and ovarian cancer. The samples collected during this study will be used for research related to both endometrial and ovarian cancer and non-cancer conditions. ELIGIBILITY: Women at least ≥18 years undergoing clinically-indicated hysterectomy and/or bilateral salpingo-oophorectomy for endometrial or ovarian cancer, cancer precursors, or benign conditions. DESIGN: 1. Participants will put a tampon in their vagina at least 30 minutes before their surgery. 2. Participants will take a short survey. 3. The tampon will be collected during the surgery. 4. A small piece of tissue will be collected from the uterus +/- ovary that is removed in surgery. 5. Participants will give a blood sample. 6. Before or after surgery, participants will answer questions. These will be about their medical history and basic data such as age and race. 7. Researchers will follow participants medical records for up to 5 years after the study. Additional blood may be taken from patient if patient agrees. 8. Researchers will study the samples and tampons. They will compare how well cancer and other markers are detected between the samples.