Circulating Tumor DNA in Tracking Minimal Residual Disease and Recurrence in Ovarian Cancer: A Retrospective Cohort

PURPOSE: After radical treatment for ovarian cancer, the presence of minimal residual disease (MRD) remains a major obstacle to achieving cure. We explored the prognostic and translational value of MRD assessment by tracking circulating tumor DNA (ctDNA) in blood using the tumor-free approach. METHODS: We retrospectively enrolled 34 ovarian cancer patients who underwent surgical treatment at our hospital, all with available postoperative and serial blood samples. ctDNA-based MRD status was analyzed to evaluate its association with recurrence risk and disease-free survival (DFS). RESULTS: In our study, the longitudinal monitoring of ctDNA showed satisfactory performance, with the sensitivity and specificity were 85% and 92.9%, respectively. 47.06%(16/34) patients had ctDNA-negative status. Patients with ctDNA positive in longitudinal monitoring have significantly worse prognosis and shorter DFS compared to those with ctDNA negative (p < 0.0001, DFS: unreached vs. 14.55 months; HR = 0.11; 95% CI, 0.05 to 0.27). A tumor-informed approach was compared with a tumor-free approach, revealing that when referring to the primary tumor mutation, 30.4% of originally positive samples were corrected to negative during MRD monitoring. CONCLUSION: ctDNA holds potential in predicting recurrence risk in ovarian cancer patients, particularly through longitudinal monitoring.