Baseline C-reactive protein predicts efficacy of the first-line immune checkpoint inhibitors plus chemotherapy in advanced lung squamous cell carcinoma: a retrospective, multicenter study

Table 1 Clinical characteristics of the patient sample at the baseline

	Overall	Chemotherapy plus ICI	Chemotherapy alone	P
	n = 245	n = 105	n = 140	P
Age (years)
median [Range]	64 [36, 84]	65 [42, 84]	62 [36, 75]	0.002
Sex (%)
Female	21 (9)	8 (8)	13 (9)	0.818
Male	224 (91)	97 (92)	127 (91)
Smoke (%)
Never smoker	16 (7)	8 (8)	8 (6)	0.737
Current/former smoker	229 (93)	97 (92)	132 (94)
ECOG score (%)
0	34 (14)	13 (12)	21 (15)	0.689
1	211 (86)	92 (88)	119 (85)
CRP (mg/L)
median [IQR]	14 [5, 38]	14 [3, 41]	14 [5, 37]	0.546
Normal ^a	84 (34)	42 (40)	42 (30)	0.135
Elevated	161 (66)	63 (60)	98 (70)
LDH (U/L)
median [IQR]	196 [168, 259]	196 [172, 253]	194 [163, 273]	0.599
Normal ^a	174 (71)	99 (71)	75 (71)	0.917
Elevated	71 (29)	41 (29)	30 (29)
NLR
median [IQR]	4 [3, 6]	4 [2, 6]	4 [3, 6]	0.285
< 3	162 (66)	72 (69)	90 (64)	0.572
≥3	83 (34)	33 (31)	50 (36)
PD-L1 expression on tumor cells
< 1%	24 (10)	17 (16)	7 (5)	0.239 ^b
1–49%	32 (13)	20 (19)	12 (9)
≥50%	15 (6)	13 (12)	2 (1)
Unknown	174 (71)	55 (52)	119 (85)
Brain metastases (%)
Absence	223 (91)	96 (91)	127 (91)	1
Presence	22 (9)	9 (9)	13 (9)
Liver metastases (%)
Absence	199 (81)	85 (81)	114 (81)	1
Presence	46 (19)	20 (19)	26 (19)
Bone metastases (%)
Absence	168 (69)	70 (67)	98 (70)	0.677
Presence	77 (31)	35 (33)	42 (30)
Type of ICI
Pembrolizumab	38 (16)	38 (36)
Nivolumab	25 (10)	25 (24)
Atezolizumab	12 (5)	12 (11)
Sintilimab	9 (4)	9 (9)
Camrelizumab	5 (2)	5 (5)
others	12 (5)	12 (11)

Abbreviations: CRP C-reactive protein, NLR neutrophil to lymphocyte ratio, LDH lactate dehydrogenase, ECOG Eastern Cooperative Oncology Group, PD-L1 programmed cell death 1 ligand 1, ICI immune checkpoint inhibitor, SD standard deviation; n, number of patients
^a Baseline CRP level and LDH level were deemed elevated if they exceeded the individual center’s reference value; otherwise, they were considered normal. ^b Statistics do not include the unknown

ISSN: 1471-2407