The usefulness of ctDNA and exosome DNA as biomarkers in esophageal squamous cell carcinoma.

Abstract

388 Background: Recently, the usefulness of exosome DNA (exo-DNA) for prognostic analysis of various solid tumors has also been reported. In this study, we investigated the usefulness of ctDNA and exo-DNA as biomarkers for esophageal squamous cell carcinoma. Methods: Patients with esophageal squamous cell carcinoma undergoing standard treatment had ctDNA and exo-DNA collected over time. NGS analysis was performed on biopsy or surgical specimens, and mutated genes in individual cases were followed by ddPCR over time. Results: NGS analysis was performed on 16 patients. 12 of 16 cases showed mutations, In 8 cases, ctDNA and exo-DNA could be measured by ddPCR over time. In one case of Stage IVA. both ctDNA and exo-DNA were useful to determine the efficacy of chemotherapy and radiotherapy, and in one case of Stage II, both ctDNA and exo-DNA were useful to predict postoperative recurrence. Conclusions: In esophageal squamous cell carcinoma, ctDNA and exo-DNA may be useful in determining treatment response and predicting recurrence. We will further investigate the usefulness of ctDNA and exo-DNA in esophageal squamous cell carcinoma, including prognostic prediction. Clinical trial information: UMIN000045311 .