Epithelial Ovarian Cancer (EOC) is the most lethal gynecological malignancy, with a high rate of recurrence due to minimal residual disease (MRD). Traditional surveillance methods have limited sensitivity for detecting MRD. ctDNA has emerged as a promising biomarker for real-time tumor monitoring and early detection of MRD. We performed a systematic search of Medline, Embase, and CENTRAL through July 2025. Eligible studies included cohort studies involving adults with EOC that reported ctDNA data, collected post-surgery or after adjuvant chemotherapy. Survival outcomes, including progression-free survival (PFS) and overall survival (OS), were extracted and stratified by ctDNA status (detectable vs. undetectable). All statistical analyses were performed at Review Manager version 5.4. This study is prospectively registered in PROSPERO (CRD420251124631). A total of 1291 records were identified, of which 11 studies met eligibility criteria, encompassing 627 patients with EOC. The pooled analysis showed that ctDNA positivity after surgery was significantly associated with worse PFS (HR 3.83; 95% CI 2.55-5.77; I²= 5% p < 0.01) and OS (HR 2.84; 95% CI 1.22-6.57; I²=0; p < 0.01) compared with ctDNA-negative patients. Similarly, post-adjuvant chemotherapy detection of ctDNA yields worse PFS (HR 4.95) and OS (HR 5.95). Our findings suggest that ctDNA is a novel instrument for MRD detection, and its presence serves as a potent prognostic indicator for recurrence and mortality in ovarian cancer. These results support integrating ctDNA into clinical trial designs and highlight its potential for risk-adapted surveillance and treatment strategies.

Background: Folate receptor alpha (FRα), commonly expressed in epithelial ovarian cancers, is a clinically actionable biomarker following approval of the antibody–drug conjugate mirvetuximab soravtansine (MIRV). Pivotal trials showed that high FRα expression predicts MIRV benefit, creating the need for standardized testing to ensure timely, equitable access. Methods: To address the need for guidance on FRα testing, the Society of Gynecologic Oncology of Canada convened a multidisciplinary Expert Panel to review the evidence and integrate Canadian clinical, pathology, laboratory, and patient perspectives. Consensus recommendations were developed through structured evidence review, expert discussion, iterative revision, and patient partner input. Results: The panel issued recommendations on the clinical role and timing of FRα testing, tissue requirements, assay selection and validation, interpretation and reporting standards, laboratory quality assurance, reimbursement, and equitable access. It is recommended that FRα testing be available to all patients with epithelial ovarian cancer, with results available no later than platinum-resistant disease, using a validated assay, preferably the Ventana FOLR1 RxDx assay or an appropriately validated laboratory-developed test. Standardized synoptic reporting, participation in external quality assurance programs, and clear patient communication were deemed essential. Conclusions: These recommendations aim to promote integrated, equitable, standardized FRα testing across Canada and support timely identification of patients eligible for FRα-directed therapy, clinical trial enrollment, and future biomarker-driven treatment strategies.