Serial circulating tumor DNA as a biomarker for monitoring and prognostication in patients with pancreatic cancer

Figure 5 Synchronized and desynchronized changes in circulating tumor DNA and carbohydrate antigen 19-9 and early detection of disease progression. A: Synchronized and desynchronized changes in circulating tumor DNA (ΔctDNA) and carbohydrate antigen 19-9 (ΔCA19-9) levels in the resection and chemotherapy groups. In the resection group, 108 events with concurrent ΔctDNA and ΔCA19-9 measurements were identified, of which 61.1% exhibited synchronized changes and 38.9% exhibited desynchronized changes. Tumor recurrence occurred in 10.2% of events, and 72.7% of recurrent cases were predicted by either ΔctDNA or ΔCA19-9. In the chemotherapy group, ΔctDNA and ΔCA19-9 levels were simultaneously measured in 273 events, with 61.9% showing synchronized changes and 38.1% showing desynchronized changes. Progressive disease (PD) was observed in 31.1% of events, and 88.2% of PD cases were predicted by either biomarker; B: Early detection of PD by ctDNA monitoring. Time to radiological progression was visualized using a swimmer plot in stable disease patients who exhibited increased ΔctDNA levels without corresponding ΔCA19-9 elevation. Each bar represents an individual patient, with the length indicating the follow-up duration. ctDNA: Circulating tumor DNA; CA19-9: Carbohydrate antigen 19-9; PR: Partial response; SD: Stable disease; PD: Progressive disease.