The most deadly gynecologic cancer is epithelial ovarian cancer (EOC). Before surgery and during follow-up after therapy, researchers investigated whether circulating tumor DNA (ctDNA) could be a useful predictive biomarker for early-stage ovarian cancer by comparing it to the patient outcome and CA-125. Plasma was taken from patients with EOC at stages I through IV. Patients in Cohort A had samples taken before surgery (N = 44, median follow-up: 2.7 years), while Cohorts B and C had samples taken serially after surgery (N = 12) and during surveillance (N = 13) (median follow-up: 2 years). 

A tumor-informed, tailored multiplex-PCR NGS assay was used to examine plasma samples, and the results showed that ctDNA status and CA-125 levels were both connected with clinical characteristics and outcomes. Every member of the their genome sequenced, and the results were in line with those found in TCGA. Cohort A had a greater rate of ctDNA-positivity in high nuclear grade illness, with 73% (32/44) of presurgical samples testing positive. Only relapsing patients’ ctDNA was found (100% sensitivity and specificity) in cohorts B and C, and it lagged behind radiological findings by an average of 10 months. 

When compared to CA-125 positive (P = 0.113 and P = 0.056), the presence of ctDNA at a single time point after surgery +/- adjuvant chemotherapy and serially during surveillance was a substantial predictor of relapse (HR:17.6, P = 0.001 and P < 0.0001, respectively). Postoperative ctDNA detection is strongly associated with poor prognosis in terms of time before cancer returns after surgery. When it came to predicting which patients will experience a recurrence, CtDNA fared better than CA-125. From these findings, it appears that ctDNA monitoring may aid in clinical decision making for individuals with EOC.