Table 4.

For patients with EGFR mutation in exon 19 or exon 21: univariate and multivariate Cox regression analyses of covariables associated with survival after the diagnosis of brain metastasis.

	Univariate analyses		Multivariate analyses
	HR (95%CI)	P-value	HR (95%CI)	P-value
Age
>65 vs. ≦65	1.32 (0.78 to 2.24)	0.302
Female vs. male	0.46 (0.28 to 0.76)	0.003	0.47 (0.28 to 0.78)	0.004
Initial Clinical stage
III–IV vs. I–II	2.57 (0.63 to 10.51)	0.19
Initial Tumor classification
III–IV vs. I–II	1.43 (0.81 to 2.51)	0.215
Initial Nodal classification
2–3 vs. 0–1	1.53 (0.91 to 2.56)	0.105
Brain surgery
Yes vs. no	0.59 (0.36 to 0.97)	0.036	0.66 (0.4 to 1.11)	0.116
RT boost dose >3750cGy
Yes vs. no	0.81 (0.48 to 1.35)	0.41
Number of lines of systemic chemotherapy
>3 vs. 0–3	1.96 (0.93 to 4.15)	0.077
TKI name
afatinib
Yes vs. no	0.45 (0.18 to 1.12)	0.86
erlotinib
Yes vs. no	0.82 (0.51 to 1.33)	0.427
gefitinib
Yes vs. no	1.49 (0.86 to 2.6)	0.159
osimertinib
Yes vs. no	0.65 (0.16 to 2.65)	0.543
Number of lines of TKI
>1 vs. 1	0.938 (0.57 to 1.54)	0.798
ECOG performance status
1 vs. 0	1.05 (0.65 to 1.71)	0.842
2 vs. 0	0.34 (0.05 to 2.46)	0.283
Smoking status
Former or current vs. never	1.43 (0.81 to 2.54)	0.216
Symptomatic brain metastases
Yes vs. no	1.13 (0.61 to 2.07)	0.697
Size of largest brain tumor
>1 cm vs ≦1 cm	1.47 (0.85 to 2.53)	0.168
No. of brain metastases
2–3 vs. 1	2.03 (0.84 to 4.91)	0.118	1.8 (0.74 to 4.4)	0.198
>3 vs. 1	2.57 (1.25 to 5.28)	0.01	2.41 (1.16 to 5)	0.018
dsGPA
0.5–1.5 vs. 2–4	1.58 (0.92 to 2.71)	0.098

Abbreviations: EGFR: epidermal growth factor receptor; RT: radiation therapy; TKI: tyrosine kinase inhibitor; ECOG: Eastern Cooperative Oncology Group; dsGPA: disease-specific Graded Prognostic Assessment.