Table 1.

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.