Table 1 Patient characteristics*other = jejunum (1),esophagus (1), endometrium (1), ovary (1), Sarcoma (1), pancreas (1), prostate (1), thyroid (1) NSCLC = non-small cell lung carcinoma, SCLC = small cell lung carcinoma, PS = performance status

Gender

 Woman

33

51.6

 Man

31

48.4

Age (years)

62.5

[21—82]

 < 65 years

39

60.9

 ≥ 65 years

25

39.1

Initial PS

 0

31

56.4

 1

21

38.2

 ≥ 2

3

5.4

 Missing

9

 Primary

 NSCLC

40

62.5

 SCLC

2

3.1

 BREAST

3

4.7

 KIDNEY

6

9.4

 Unknown

2

3.1

 Colorectal

3

4.7

 Other

8

12.9

Extracranial metastasis

 Yes

25

44.6

 No

31

55.4

 Missing

8

First brain metastasis

 Yes

24

38.1

 No

39

61.9

 Missing

1

RPA class

2 [1–3]

 1

9

16.4

 2

43

78.2

 3

3

5.4

 Missing

9

GPA score

2.5 [0–4]

Lung adenocarcinoma

37

100

 Mutation KRAS

13

40.6

 Mutations EGFR

3

9.4

 Mutation HER2

1

3.1

 Translocation ALK

1

3.1

 No mutations

14

43.8

 Missing

5

Mutation analysis

 On primary

Aug-37

21.6

 On metastasis brain

29/37

78.4