Longitudinal analysis of ctDNA for disease monitoring and acquired resistance to treatment
PD, tumor, BOR
ADVERSE EVENTS, TUMOR, DISEASE
To track ctDNA fraction from baseline to EOT, a longitudinal analysis of ctDNA levels in individual patients was performed that grouped patients by BOR into 4 categories, as described in the previous section. Patients who had radiological progression at the first scan showed dynamic changes in ctDNA between C1D1 and EOT (Fig. Longitudinal trajectories of ctDNA fraction in patients with evaluable response. Excluded 8 patients who discontinued treatment due to adverse events. Abbreviations: BL, baseline; ctDNA, circulating tumor DNA; PD, progressive disease; PR, partial response; SD, stable diseaseLead time in detecting PD. Included all patients that clinically progressed and have ctDNA > 0 in 2 consecutive visits. Abbreviations: BL, baseline; ctDNA, circulating tumor DNA. Yes: time point used for calculation of lead time. No: all other timepointsThe correlation between ctDNA levels and tumor volume with treatment is still poorly understood and can be especially complex for different genetic alterations. Therefore, a longitudinal analysis of the percentage of ctDNA fraction change and its correlation with the percentage of change in tumor diameter was performed for each response group (Fig. Longitudinal analyses of ctDNA fraction change and correlation with change in tumor diameter by response. Abbreviations: BL, baseline; ctDNA, circulating tumor DNA; NA, not available; PD, progressive disease; PR, partial response; SD, stable diseaseA more detailed longitudinal analysis of ctDNA change and its correlation with tumor diameter for individual patients was performed (Fig. Case studies. 