Perioperative ctDNA as a prognostic biomarker in endometrial cancer - The CODEC Study.

Abstract

PurposeBiomarkers to predict relapse and guide adjuvant therapy selection are needed in endometrial cancer (EC), one of the few cancers increasing in incidence and mortality. Assessment of ctDNA at multiple perioperative time points has not been explored in EC. This study aimed to assess the utility of ctDNA as a prognostic biomarker at four perioperative time points, explore ctDNA dynamics, and compare tumour measurement by ctDNA to 18F-Fluorodeoxyglucose PET/CT and MRI imaging modalities. Patients and MethodsParticipants with Type 2 EC planned for surgery and consenting to the collection of biospecimens were enrolled prior to surgery and followed prospectively. Participants had preoperative imaging and tumour sequencing was performed using hybrid capture, which guided the design of droplet digital PCR (ddPCR) assays for ctDNA analysis. The primary study endpoint was relapse free survival. ResultsA total of 50 participants were enrolled in the CODEC study. The genomic findings were consistent with the previously described landscape in EC. Detection of ctDNA postoperatively is suggestive of minimal residual disease and associated with poorer relapse free survival. While ctDNA was detected at the other perioperative time points, it was not significantly associated with outcome. The ctDNA level (copies/millilitre) correlated with both FDG-PET and MRI determined tumour volume. ConclusionOur findings support the use of the postoperative assessment of ctDNA for prognostic purposes and provides evidence to support further investigation of ctDNA in EC, including whether it can be used to guide adjuvant therapy selection.Copyright © 2025, The Authors. All rights reserved.