Patient characteristics
| Decrease in plasma allele fraction at first follow-up (n=28) | Increase in plasma allele fraction at first follow-up (n=17) | P value | |
| Age, median (range) | 64 (39–89) | 63 (43-80) | 0.73 |
| Sex | 1.0 | ||
| Male | 8 (28.6) | 4 (23.5) | |
| Female | 20 (71.4) | 13 (76.5) | |
| Histology | 1.0 | ||
| Adenocarcinoma | 25 (89.3) | 15 (88.2) | |
| Squamous | 3 (10.7) | 2 (11.8) | |
| ECOG performance status | 0.18 | ||
| 0–1 | 26 (92.9) | 13 (76.5) | |
| ≥2 | 2 (7.1) | 4 (23.5) | |
| Smoking status | 0.14 | ||
| Current/former | 28 (100.0) | 15 (88.2) | |
| Never | 0 (0.0) | 2 (11.7) | |
| Driver mutation by tissue sequencing | 0.46 | ||
| KRAS | 14 (53.8) | 5 (31.2) | |
| EGFR | 1 (3.8) | 2 (7.7) | |
| BRAF | 3 (11.5) | 2 (7.7) | |
| HER2 | 1 (3.8) | 0 (0.0) | |
| None identified | 7 (26.9) | 7 (43.7) | |
| Not assessed | 2 | 1 | |
| Treatment received: | 0.38 | ||
| Pembrolizumab | 12 (42.9) | 12 (70.6) | |
| Carboplatin/pemetrexed/pembrolizumab | 16 (57.1) | 5 (29.4) | |
| PD-L1 expression | 0.51 | ||
| <50% | 10 (43.5) | 5 (29.4) | |
| ≥50% | 13 (56.5) | 12 (70.6) | |
| Not assessed | 5 | ||
| TMB, median (range) | 9.1 (3.8–26.6) | 11.4 (3.8–16.7) | 0.88 |
ECOG, Eastern Cooperative Oncology Group; PD-L1, programmed death ligand 1; TMB, tumor mutational burden.