Clinical characteristics and prognosis of non-small cell lung cancer patients with liver metastasis: A population-based study

Table 1 Baseline characteristics of the overall, training, and validation cohorts

Characteristic	Overall cohort (n = 4475)	Training cohort (n = 3135)	Validation cohort (n = 1340)	P value
Age, yr				0.839
Median (range)	67 (23-96)	67 (23-96)	66 (32-93)
< 65	1930 (43.1)	1349 (43.0)	581 (43.4)
≥ 65	2545 (56.9)	1786 (57.0)	759 (56.6)
Marital status				0.413
Married	2463 (55.0)	1713 (54.6)	750 (56.0)
Unmarried	2012 (45.0)	1422 (45.4)	590 (44.0)
Sex				0.808
Female	1938 (43.3)	1354 (43.2)	584 (43.6)
Male	2537 (56.7)	1781 (56.8)	756 (56.4)
Race				0.263
Black	566 (12.6)	413 (13.2)	153 (11.4)
White	3517 (78.6)	2451 (78.2)	1066 (79.6)
Other1	392 (8.8)	271 (8.6)	121 (9.0)
Primary site				0.922
UL	2452 (54.8)	1725 (55.0)	727 (54.3)
ML	198 (4.4)	133 (4.2)	65 (4.9)
LL	1219 (27.2)	853 (27.2)	366 (27.3)
MB	240 (5.4)	167 (5.3)	73 (5.4)
Other	366 (8.2)	257 (8.2)	109 (8.1)
Histological type				0.786
ADC	2967 (66.3)	2085 (66.5)	882 (65.8)
SCC	1169 (26.1)	810 (25.8)	359 (26.8)
Other NSCLCs	339 (7.6)	240 (7.7)	99 (7.4)
T stage				0.910
T1	507 (11.3)	362 (11.5)	145 (10.8)
T2	1197 (26.7)	839 (26.8)	358 (26.7)
T3	1204 (26.9)	839 (26.8)	365 (27.2)
T4	1567 (35.0)	1095 (34.9)	472 (35.2)
N stage				0.170
N0	831 (18.6)	596 (19.0)	235 (17.5)
N1	358 (8.0)	239 (7.6)	119 (8.9)
N2	2312 (51.7)	1601 (51.1)	711 (53.1)
N3	974 (21.8)	699 (22.3)	275 (20.5)
Metastatic pattern				0.166
Liver only	1598 (35.7)	1117 (35.6)	481 (35.9)
Liver + bone	1701 (38.0)	1166 (37.2)	535 (39.9)
Liver + brain	415 (9.3)	301 (9.6)	114 (8.5)
Liver + bone + brain	761 (17.0)	551 (17.6)	210 (15.7)
Radiotherapy				0.497
Yes	1871 (41.8)	1321 (42.1)	550 (41.0)
No/unknown	2604 (58.2)	1814 (57.9)	790 (59.0)
Chemotherapy				0.287
Yes	2417 (54.0)	1677 (53.5)	740 (55.2)
No/unknown	2058 (46.0)	1458 (46.5)	600 (44.8)

¹Other only includes American Indian/Alaskan Native and Asian/Pacific Islander.

UL: Upper lobe; ML: Middle lobe; LL: Lower lobe; MB: Main bronchus; ADC: Adenocarcinoma; SCC: Squamous cell carcinoma; NSCLC: Non-small cell lung cancer.

Table 2 Univariate and multivariate analyses of cancer-specific survival in the training cohort

Characteristic	Univariate analysis			Multivariate analysis
	HR	95%CI of HR	P value	HR	95%CI of HR	P value
Age, yr
≥ 65 vs < 65	1.312	1.221-1.411	< 0.001	1.236	1.147-1.332	< 0.001
Marital status
Unmarried vs Married	1.245	1.158-1.338	< 0.001	1.103	1.023-1.189	0.011
Sex
Male vs Female	1.219	1.134-1.311	< 0.001	1.196	1.109-1.289	< 0.001
Race
White vs Black	1.128	1.043-1.221	0.003	1.061	0.953-1.182	0.281
Other1 vs Black	0.781	0.714-0.855	< 0.001	0.718	0.610-0.844	< 0.001
Pathological type
ADC vs SCC	0.814	0.749-0.884	< 0.001	0.905	0.829-0.988	0.026
Other NSCLCs vs SCC	0.786	0.677-0.913	0.002	0.880	0.756-1.025	0.101
T stage
T2 vs T1	1.195	1.052-1.357	0.006	1.179	1.037-1.340	0.012
T3 vs T1	1.277	1.124-1.451	< 0.001	1.226	1.078-1.395	0.002
T4 vs T1	1.358	1.201-1.536	< 0.001	1.308	1.155-1.482	< 0.001
N stage
N1 vs N0	1.050	0.901-1.225	0.530	-	-	-
N2 vs N0	1.019	0.925-1.122	0.709	-	-	-
N3 vs N0	0.988	0.883-1.105	0.831	-	-	-
Metastatic pattern
Liver + bone vs Liver only	1.181	1.086-1.285	< 0.001	1.281	1.176-1.396	< 0.001
Liver + brain vs Liver only	1.328	1.166-1.512	< 0.001	1.541	1.351-1.758	< 0.001
Liver + bone+ brain vs liver only	1.244	1.121-1.381	< 0.001	1.562	1.400-1.742	< 0.001
Radiotherapy
Yes vs No/unknown	0.967	0.900-1.040	0.364	-	-	-
Chemotherapy
Yes vs No/unknown	0.346	0.321-0.373	< 0.001	0.352	0.326-0.381	< 0.001

¹Other only includes American Indian/Alaskan Native and Asian/Pacific Islander.

HR: Hazard ratio; CI: Confidence interval; ADC: Adenocarcinoma; SCC: Squamous cell carcinoma; NSCLC: Non-small cell lung cancer.

Table 3 Corresponding nomogram scores of each variable

Characteristic	Nomogram score
Age, yr
< 65	0
≥ 65	20.09207
Marital status
Married	0
Unmarried	9.018027
Sex
Female	0
Male	16.9568
Race
Black	31.70234
White	37.39893
Other1	0
Histological type
ADC	2.971477
SCC	12.914637
Other NSCLCs	0
T stage
T1	0
T2	16.23500
T3	21.12835
T4	27.17024
Metastatic pattern
Liver only	0
Liver + bone	23.05159
Liver + brain	41.91404
Liver + bone + brain	43.49717
Chemotherapy
Yes	0
No/unknown	100

¹Other only includes American Indian/Alaskan Native and Asian/Pacific Islander.

ADC: Adenocarcinoma; SCC: Squamous cell carcinoma.