Table 1 Baseline characteristics of EGFR-mutated lung adenocarcinoma patients with brain metastases in the training cohort and validation cohort

Gender

0.650

 Male

49(40.8%)

27(36.5%)

 Female

71(59.2%)

47(63.5%)

Age

0.462

 < 60

63(52.5%)

43(58.1%)

 ≥ 60

57(47.5%)

31(41.9%)

Smoker

0.851

 Yes

23(19.2%)

13(17.6%)

 No

97(80.8%)

61(82.4%)

KPS

0.359

 < 80

72(60.0%)

50(67.6%)

 ≥ 80

48(40.0%)

24(32.4%)

Location

0.293

 Left lung

68(56.7%)

48(64.9%)

 Right lung

52(43.3%)

26(35.1%)

EGFR mutation type

0.339

 Common

115(95.8%)

68(91.9%)

 Uncommon

5(4.2%)

6(8.1%)

Number of BMs

1.000

 ≤ 5

70(58.3%)

43(58.1%)

 > 5

50(41.7%)

31(41.9%)

Volume of BMs

0.348

Location of BMs

0.548

 Only in the hemispheres of the brain

52(43.3%)

28(37.8%)

 Exist in other location

68(56.7%)

46(62.2%)

Symptoms of BM

0.701

 Yes

20(16.7%)

14(18.9%)

 No

100(83.3%)

60(81.1%)

T categories of TNM

0.314

 = 1

35(29.2%)

16(21.6%)

 > 1

85(70.8%)

58(78.4%)

N categories of TNM

0.296

 < 3

73(60.8%)

39(52.7%)

 ≥ 3

47(39.2%)

35(47.3%)

Hepatic metastases

0.315

 Yes

22(18.3%)

9(12.2%)

 No

98(81.7%)

65(87.8%)

Bone metastases

0.765

 Yes

70(58.3%)

41(55.4%)

 No

50(41.7%)

33(44.6%)

Pleural metastases

0.255

 Yes

19(15.8%)

17(23.0%)

 No

101(84.2%)

57(77.0%)

Adrenal metastases

 Yes

14(11.7%)

7(9.5%)

 No

106(88.3%)

67(90.5%)

Combined with chemotherapy or anti blood vessel

0.124

 Yes

37(30.8%)

31(41.9%)

 No

83(69.2%)

43(58.1%)

First-line therapy

0.655

 Yes

71(59.2%)

41(55.4%)

 No

49(40.8%)

33(44.6%)