Survival benefits of concurrent immune checkpoint inhibitor and radiotherapy in non-small cell lung cancer with brain metastases

Table 1 General characteristics of non-small cell lung cancer patients with brain metastases in the concurrent immune checkpoint inhibitor group and consolidation immune checkpoint inhibitor group, n (%)

Characteristic	Concurrent ICI, N = 54	Consolidation ICI, N = 62	P value
Age, years			0.536
≤ 65	17 (31.5)	26 (41.9)
> 65	37 (68.5)	36 (58.1)
Sex			0.492
Male	33 (61.1)	34 (54.8)
Female	21 (38.9)	28 (45.2)
ECOG			0.735
0-1	12 (22.2)	17 (27.4)
2	42 (77.8)	45 (72.6)
Smoking			0.598
Yes	36 (66.7)	27 (43.5)
No	18 (33.3)	35 (56.5)
Histology			0.727
Squamous cell carcinoma	9 (16.7)	14 (22.6)
Adenocarcinoma	40 (74.1)	45 (72.6)
Other types	5 (9.3)	3 (4.8)
Tumor proportion score, %			0.712
≤ 1	19 (35.2)	20 (32.3)
1-49	8 (14.8)	6 (9.7)
≥ 50	15 (27.8)	22 (35.4)
Unknown	12 (22.2)	14 (22.6)
Number of brain metastases			0.421
≤ 3	43 (79.6)	44 (71.0)
> 3	11 (20.4)	18 (29.0)
Tumor diameters, mm			0.335
≤ 20	38 (70.4)	47 (75.8)
> 20	16 (29.6)	15 (24.2)
KRAS mutation			0.256
Positive	5 (9.3)	9 (14.5)
Wild type	49 (90.7)	53 (85.5)
TP53 mutation			0.398
Positive	7 (13.0)	8 (12.9)
Wild type	47 (87.0)	54 (87.1)
First line therapy			0.864
Yes	38 (70.4)	46 (74.2)
No	16 (29.6)	16 (25.8)
Extracranial metastases			0.710
Yes	33 (61.1)	35 (56.5)
No	21 (38.9)	27 (43.5)

ECOG: Eastern Cooperative Oncology Group; KRAS: Kirsten rat sarcoma viral oncogene; TP53: Tumor protein 53; ICI: Immune checkpoint inhibitor.

Table 2 Treatment response analysis, n (%)

Treatment response	Concurrent ICI, n = 54	Consolidation ICI, n = 62	P value
CR	12	11
PR	24	26
SD	13	18
PD	5	7
ORR	36 (66.7)	37 (59.7)	0.389

CR: Complete response; ICI: Immune checkpoint inhibitor; PR: Partial response; SD: Stable response; PD: Progressive disease; ORR: Objective response rate.

Table 3 Cox proportional hazards regression for overall survival

Variable	Univariate analysis		Multivariate analysis
	HR (95%CI)	P value	HR (95%CI)	P value
Age (> 65 vs ≤ 65)	0.871 (0.575-1.325)	0.423
Sex (male vs female)	0.908 (0.599-1.218)	0.278
Smoking (yes vs no)	1.071 (0.764-1.595)	0.649
ECOG (0-1 vs 2)	2.402 (0.752-7.675)	0.139
Number of brain metastases (≤ 3 vs > 3)	0.357 (0.264-0.795)	0.009	0.407 (0.299-0.857)	0.011
Tumor diameters (≤ 20 mm vs > 20 mm)	1.142 (0.752-1.675)	0.339
KRAS mutation (positive vs wild type)	0.432 (0.258-1.113)	0.405
TP53 mutation (positive vs wild type)	1.489 (1.096-2.021)	0.081
First line therapy (yes vs no)	0.612 (0.434-1.019)	0.003	0.658 (0.491-1.134)	0.025
ICI (concurrent vs consolidation)	0.385 (0.347-1.036)	0.009	0.432 (0.386-1.097)	0.007
Extracranial metastases (yes vs no)	1.601 (1.242-1.979)	0.014	1.844 (0.299-2.189)	0.036

HR: Hazard ratio; CI: Confidence interval; ECOG: Eastern Cooperative Oncology Group; KRAS: Kirsten rat sarcoma viral oncogene; TP53: Tumor protein 53; ICI: Immune checkpoint inhibitor.