Discussion
In this longitudinal ctDNA analysis of MONALEESASIA, the most frequently altered genes at baseline were In this analysis, The use of less-invasive liquid biopsy to collect longitudinal ctDNA samples was an advantage of this analysis; however, this technology and this analysis have some limitations. Detection of copy numbers in ctDNA samples is limited, especially for deletions; therefore, the data presented may underestimate the total frequency of amplified genes, large deletions, and rearrangements. Variability in ctDNA levels between patients could affect the VAF of mutations in individual genes (for example, see Fig. 