Table 1. Baseline characteristics.

Variables	Pyrotinib + radiotherapy (N=35)	Pyrotinib (N=44)	P value
Age, years	45 [30–58]	46 [24–69]	0.39
DFS, months	14.5 [0–120]	17.0 [0–108]
Hormone receptor type			0.12
HR positive	14 (40.0)	26 (59.1)
HR negative	21 (60.0)	18 (40.9)
TNM staging			0.92
I	3 (8.6)	3 (6.8)
II	12 (34.3)	17 (38.6)
III	14 (40.0)	15 (34.1)
IV	6 (17.1)	9 (20.5)
Metastasis at diagnosis			0.23
Single	8 (22.9)	16 (36.4)
Multiple	27 (77.1)	28 (63.6)
Meningeal metastasis			0.50
Yes	5 (14.3)	4 (9.1)
No	30 (85.7)	40 (90.9)
Any symptom after diagnosis			0.80
Yes	10 (28.6)	11 (25.0)
No	25 (71.4)	33 (75.0)
Extracranial metastasis
Lymph node metastasis	26 (74.3)	27 (61.4)	0.05
Bone metastasis	18 (51.4)	26 (59.1)	0.65
Hepatic metastasis	19 (54.3)	21 (47.7)	0.65
Lung metastasis	13 (37.1)	23 (52.3)	0.26
Active brain metastasis	29 (82.9)	22 (50.0)	0.004
Stable brain metastasis	6 (17.1)	22 (50.0)
Brain radiotherapy before treatment			0.001
Yes	5 (14.3)	24 (54.5)
No	30 (85.7)	20 (45.5)
HER2-targeted therapy lines			0.07
<2	19 (54.3)	14 (31.8)
≥2	16 (45.7)	30 (68.2)
Previously received treatment
Trastuzumab	31 (88.6)	38 (86.4)	0.52
Pertuzumab	2 (5.7)	8 (18.2)	0.07
Lapatinib	13 (37.1)	28 (63.6)	0.45
Pyrotinib	4 (11.4)	3 (6.8)	0.69
T-DM1	1 (2.9)	2 (4.5)	0.59
Treatment regimen			0.02
Pyrotinib alone	12 (34.3)	12 (27.3)	0.501
Pyrotinib + chemotherapy	18 (51.4)	25 (56.8)	0.476
Pyrotinib + endocrine therapy	5 (14.3)	7 (15.9)	0.842

Data are shown as median [interquartile range] or number (percentage). DFS, disease-free survival; HR, hormone receptor; HER2, human epidermal growth factor receptor type 2; T-DM1, trastuzumab emtansine.