Fig. 4.

Longitudinal allele frequency tracking of ctDNA mutations. Somatic mutations were first identified in the primary tumor. These mutations were then searched for in matched plasma samples. ctDNA mutations were identified in four patients at varying allele frequencies. From patient 146-0005(a) and patient 146-0013(b), the increasing allele frequency of ctDNA was observed before clinically recurrence was diagnosed. Patient 146-0102(c) and patient 146-0112(d) had only one timepoint plasma sample available, and we were able to detect the ctDNA before clinical recurrence as well. The lead-time range was 0.07 to 8.87 months