Blood-Based Minimal Residual Disease in Advanced Epithelial Ovarian Cancer After 1st Line Therapy

The purpose of this observational study is to learn if a specialized blood test can help predict whether advanced ovarian cancer will return after a patient's initial treatments are finished. Researchers are inviting women who have been diagnosed with stage III or IV epithelial ovarian cancer and have recently completed their first-line treatments, which include surgery and platinum-based chemotherapy. The study focuses on "circulating tumor DNA" (ctDNA), which are tiny fragments of genetic material that cancer cells release into the bloodstream as they break down. Finding these DNA fragments in the blood when a patient appears to be cancer-free on standard tests is known as assessing for minimal residual disease (MRD). Because this is an observational study, participants will receive standard medical care as directed by their doctor. For the research portion, participants will provide blood samples at specific times: at the time of diagnosis, shortly after surgery, right after finishing their first-line chemotherapy, and then every 3 months during regular follow-up visits. Researchers will also analyze a sample of the tumor tissue that was already removed during the patient's standard surgery. By tracking these participants for up to 3 years, researchers hope to discover if the ctDNA test can accurately identify patients who have a high risk of their cancer returning, and if it can detect this earlier than traditional imaging scans or standard blood tests like CA-125.