EGFR mutations are associated with favorable intracranial response and progression-free survival following brain irradiation in non-small cell lung cancer patients with brain metastases

Table 3 Univariate and multivariable analyses of clinical characteristics in predicting intracranial radiological progression-free survival

Characteristics	Univariate analysis			Multivariable analyses
	HR	95% CI of HR	P	HR	95% CI of HR	P
Age, years (≧60 vs. <60)	1.07	0.35 to 3.32	0.904
Gender (male vs. female)	1.27	0.42 to 3.84	0.673
Smoking history (ever vs. never)	1.59	0.51 to 4.94	0.419
EGFR mutation status (positive vs. negative)	0.20	0.05 to 0.77	0.020	0.20	0.05 to 0.81	0.025
Mutant EGFR^† (exon 21 vs. exon 19)	1.49	0.40 to 5.61	0.555
ECOG performance status	1.66	0.84 to 3.27	0.144
RPA class			0.022^‡			0.026‡
Class I (reference)	1	--	--	1	--	--
Class II	3.00	0.37 to 24.43	0.306	2.54	0.30 to 21.36	0.390
Class III	12.67	1.18 to 136.31	0.036	12.26	1.08 to 138.65	0.043
Primary tumor status (uncontrolled vs. controlled)	1.46	0.37 to 5.80	0.588
Extracranial metastases (present vs. absent)	0.71	0.23 to 2.19	0.549
Number of BM (>3 vs. ≦3)	1.02	0.33 to 3.14	0.970
Size of largest BM (mm)	1.01	0.97 to 1.05	0.560
Hemorrhagic BM (yes vs. no)	0.76	0.23 to 2.58	0.664
Total dose (>40 Gy₂ vs. ≦40 Gy₂)	0.86	0.23 to 3.28	0.825
EGFR TKI during RT (yes vs. no)	1.32	0.44 to 3.97	0.620
Type of EGFR TKI^§ (erlotinib vs. gefitinib)	1.39	0.16 to 11.98	0.764
Chemotherapy during RT (yes vs. no)	0.95	0.26 to 3.46	0.940

Abbreviations: HR hazard ratio, CI confidence interval, ECOG Eastern Cooperative Oncology Group, RPA recursive partitioning analysis, BM brain metastases, Gy₂ biologically equivalent dose equal to fraction size of 2 Gy, TKI tyrosine kinase inhibitor.
† n = 30.
§ n = 19.
‡ P for linear trend.

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