Circulating-tumor DNA from Two Types of Blood Collection Tubes for Monitoring Tumor Burden Validated with Esophageal Squamous Cell Carcinoma Patients

Objective: To evaluate long-term whole blood (WB) storage at room temperature (RT), plasma and peripheral blood mononuclear cell (PBMC) DNA was collected simultaneously using BD Vacutainer(R) CPT Mononuclear Cell Preparation Tubes (CPT) and Streck Cell-Free DNA Blood Collection Tubes (BCT(R)). Methods: Plasma DNA was isolated from both types of tubes at various time points at RT. DNA from PBMCs was extracted using CPT from WB stored in BCT. The extracted DNA was used to monitor esophageal cancer treatment. Results: BCT maintained steady levels of plasma DNA for up to nine days. After transfer of BCT-stored WB to CPT, PBMC-DNA were yielded with suitable quality for up to seven days. ctDNA from esophageal cancer patients carrying TP53 mutations reflected treatment efficacy. Conclusion: BCT/CPT combinatory procedure allows storage of blood samples for up to seven days at RT for valid clinical assays using ctDNA.