Table 3 GAs and factors affect the detection of GAs in the plasma ctDNA assay

Specimen type

Frozen plasma

Fresh whole blood

All samples

Volume (mL)

~ 3.0

8.5 (5.5–11.5)

8.0 (3.0–11.5)

cfDNA (ng/mL)

2.5 ± 5.0

14.2 ± 32.2

P = 0.023

GA ≥ 1

13 (93%)

56 (84%)

69 (85%)

Total number of GAs (average/case, range)

49 (3.5/case; 1–9)

166 (2.5/case; 1–11)

215 (2.7/case; 1–11)

 Base substitutions

36 (73%)

118 (71%)

154 (72%)

 Insertions/deletions

8 (16%)

26 (16%)

34 (16%)

 Amplifications

1 (2%)

13 (8%)

14 (7%)

Rearrangements/fusions

4 (8%)

9 (5%)

13 (6%)

cfDNA (mean ± SD) ng/mL; (GA ≥ 1 vs GA = 0)

3.1 ± 5.9 vs 0.3 ± 0.1 (P = 0.5293)

8.6 ± 18.1 vs 18.9 ± 51.6 (P = 0.2314)

7.6 ± 16.7 vs 16.3 ± 47.3 (P = 0.2362)

MSAF (mean ± SD); (GA ≥1 vs GA = 0)

0.0648 ± 0.0823 vs 0.0005 ± 0.0007 (P = 0.3062)

0.1219 ± 0.2031 vs 0.0003 ± 0.0009 (P = 0.0432)

0.1117 ± 0.1880 vs 0.0003 ± 0.0009 (P = 0.0304)

Tumor burden by RECIST V1.1 cm (GA ≥ 1 vs GA = 0) (mean ± SD)

7.6 ± 6.4 vs 12.0 ± 12.0 (P = 0.4610)

9.8 ± 5.8 vs 5.7 ± 3.4 (P = 0.0292)

9.4 ± 5.9 vs 6.6 ± 5.3 (P = 0.1301)

Tumor metabolic activity by SUVmax mg/dL (GA ≥1 vs GA = 0) (mean ± SD)

51.1 ± 34.8 vs 31.2 ± 30.7 (P = 0.4772)

48.1 ± 29.5 vs 14.3 ± 12.6 (P = 0.0006)

48.6 ± 30.2 vs 16.9 ± 15.8 (P = 0.0006)