Table 1. Patients’ characteristic.

	BM and ECM ( n =184)		BO ( n =38)
Characteristic	n	%	n	%	χ2 Test/t-test
Age at first diagnosis of breast cancer (years)
Median	48.5		52		0.92
Range	26–79		34–79
Breast cancer subtype
Luminal	45	24.5	13	34.2	0.19
Her2-positive	92	50.0	13	34.2
Triple-negative	47	25.5	12	31.6
Stage IV at first diagnosis
Yes	26	14.2	1	2.6	0.5
No	157	85.8	37	97.4
Chemotherapy before diagnosis of BM
Yes	169	91.8	33	86.8	0.33
No	15	8.2	5	13.2
Her2-targeted therapy before BM
Yes	70	76.1	7	53.8	0.90
No	22	23.9	6	46.2
Age at first diagnosis of BM (years)
Median	52.5		54.5		0.48
Range	26–81		36–83
Time to BM from first diagnosis of breast cancer (months)
Median	41.0		30.0		0.02
Range	0–200		0–116
Number of BM
Mean	3		2		0.36
Range	1–20		1–8
Karnofsky performance status at first diagnosis of BM
>70	167	90.8	36	94.7	0.43
<70	17	9.2	2	5.3
DS-GPA
Class I	43	23.4	6	15.8
Class II	81	44.0	18	47.4
Class III	51	27.7	12	31.6	0.78
Class IV	9	4.9	2	5.3
Metastatic pattern at first diagnosis of BM
Visceral metastases	129	58.1	0	0	—
Lung metastases	86	38.7	0	0
Liver metastases	79	35.6	0	0
Lymph metastases only	5	2.3	0	0
Bone metastases only	7	3.2	0	0
First-line treatment for BM
Radiosurgery	19	10.3	3	7.9	0.002
Chemotherapy	1	0.5	1	2.6
Surgery	71	38.6	27	71.1
WBRT	88	47.8	7	18.4
Best supportive care	5	2.7	0	0
Chemotherapy after diagnosis of BM
Yes	77	41.8	8	21.1	0.016
No	107	58.2	30	78.9
Systemic progression after treatment for BM
Yes	84	45.7	0	0	—
No	100	54.3	38	100
BM progression
Yes	62	33.7	14	36.8	0.71
No	122	66.3	24	63.2
OS from diagnosis of BM (months)
Median	6		11		0.007
Range	0–104		0–69
Survival beyond 3 years
Yes	5	2.7	7	18.4	<0.001
No	179	97.3	31	81.6

Abbreviations: BM=brain metastases; BO=brain-only; DS-GPA=diagnosis-specific graded prognostic assessment; ECM=extracranial metastases; OS=overall survival; WBRT=whole brain radiotherapy.