Efficacy and safety of anti-PD-1 inhibitor versus anti-PD-L1 inhibitor in first-line treatment of extensive-stage small cell lung cancer: a multicenter retrospective study

Table 1 Demographics and baseline characteristics of patients included

	Total (n = 154)	PD-1 group (n = 68)	PD-L1 group (n = 86)	χ²	p value
Sex (%)				0.631	0.427
Male	135 (87.7)	58 (85.3)	77 (89.5)
Female	19 (12.3)	10 (14.7)	9 (10.5)
Age (%)				2.898	0.089
≤ 65	102 (66.2)	50 (73.5)	52 (60.5)
> 65	52 (33.8)	18 (26.5)	34 (39.5)
Liver metastases (%)				1.758	0.185
No	125 (81.2)	52 (76.5)	73 (84.9)
Yes	29 (18.8)	16 (23.5)	13 (15.1)
Brain metastases (%)				0.745	0.388
No	129 (83.8)	55 (80.9)	74 (86)
Yes	25 (16.2)	13 (19.1)	12 (14)
Bone metastases (%)				0.134	0.714
No	111 (72.1)	48 (70.6)	63 (73.3)
Yes	43 (27.9)	20 (29.4)	23 (26.7)
Smoking history (%)				1.646	0.200
No	44 (28.6)	23 (33.8)	21 (24.4)
Yes	110 (71.4)	45 (66.2)	65 (75.6)
ECOG PS (%)				0.011	0.918
≤ 1	140 (90.9)	62 (91.2)	78 (90.7)
> 1	14 (9.1)	6 (8.8)	8 (9.3)
Cycles of chemotherapy plus ICI
4	52 (33.8)	28 (41.2)	24 (27.9)	2.426	0.119
6	102 (66.2)	40 (58.8)	62 (72.1)
chemotherapy regimen (%)				1.401	0.496
EP	65 (42.2)	32 (47.1)	33 (38.4)
EC	72 (46.8)	30 (44.1)	42 (48.8)
EL	17 (11.0)	6 (8.8)	11 (12.8)
immunotherapy regimen (%)
pembrolizumab		14 (20.6)	-
nivolumab		6 (8.8)	-
sintilimab		33 (48.5)	-
toripalimab		12 (17.6)	-
camrelizumab		3 (4.5)	-
atezolizumab		-	27 (31.4)
durvalumab		-	59 (68.6)
Locoregional thoracic radiotherapy(%)				0.229	0.632
No	85 (55.2)	39 (57.4)	46 (53.5)
Yes	69 (44.8)	29 (42.6)	40 (46.5)
LDH(%)				0.825	0.364
≤ 250	82 (53.2)	39 (57.4)	43 (50.0)
>250	72 (46.8)	29 (42.6)	43 (50.0)

EP: etoposide + cisplatin; EC: etoposide + carboplatin; EL: etoposide + lobaplatin. LDH: lactate dehydrogenase

ISSN: 1471-2407