Table 4.
Comparison of cfDNA in Pleural Fluid and Plasma
| Measurement | Pleural Fluid | Plasma | P Value for Difference |
|---|---|---|---|
| Concentration of cfDNA– Copies of amplifiable DNA/mL, Median (IQR) |
28,444 (4,957-67,051) N = 53 |
2,966.5 (2,167-5,025) N = 26 |
< .01 |
| No. of mutant molecules per mL N = 15a Median (IQR) |
2,507 (157-42,732) | 26 (4-221) | < .01 |
| Variant allele fraction % N = 15a Median (IQR) |
19.14 (0.71-50.9) | 0.47 (0.13-5.56) | < .01 |
cfDNA = cell-free DNA; IQR = interquartile range.
a
Matched patients with positive primary mutations in both pleural fluid and plasma.