Table 4.

Cox proportional hazards regression of all patients for intracranial progression

Variables	Hazard ratio (95% CI)	p value
Age > 65	1.12 (0.771 to 1.615)	0.561
Sex (male)	0.93 (0.617 to 1.395)	0.718
Smoking	1.06 (0.594 to 1.900)	0.838
EGFR mutation
L858R only	Reference
Del 19 only	0.94 (0.643 to 1.363)	0.729
Uncommon mutation	2.26 (0.802 to 6.341)	0.123
Complex mutations	2.95 (1.050 to 8.264)	0.040
Initial brain metastases number ≥ 3	1.16 (0.800 to 1.685)	0.432
RT to brain before 1st PD	0.80 (0.535 to 1.191)	0.270
Brain tumor excision	0.91 (0.608 to 1.362)	0.209
TKI
Gefitinib	Reference
Erlotinib	0.85 (0.568 to 1.283)	0.447
Afatinib	1.00 (0.602 to 1.662)	1.000