TF and neoplasm: Elevated tumour fraction (TF, ≥10%) in either baseline (n=5) or postsystemic therapy samples (n=3) was associated with poorer EFS (median EFS: 3.5 vs 16.7 months, p=0.014; median EFS: 1.4 vs 16.7 months, p=0.003) (online supplemental figure 2A,B), and TF reduction between baseline and postsystemic therapy (TF decrease <0, n=5; TF decrease ≥0, n=21) was associated with better EFS (median EFS: 3.9 vs 16.7 months, p=0.035) (online supplemental figure 2C).