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 2 Univariate and multivariable analyses of clinical characteristics in predicting radiographic response to brain RT

Characteristics	Univariate analysis			Multivariable analyses
	OR	95% CI of OR	P	OR	95% CI of OR	P
Age, years (≧60 vs. <60)	0.48	0.13 to 1.81	0.277
Gender (male vs. female)	0.98	0.27 to 3.61	0.975
Smoking history (ever vs. never)	0.93	0.24 to 3.54	0.911
EGFR mutation status (positive vs. negative)	4.67	1.14 to 19.12	0.032	4.67	1.14 to 19.12	0.032
Mutant EGFR^† (exon 21 vs. exon 19)	0.42	0.06 to 2.77	0.369
ECOG performance status	0.73	0.34 to 1.56	0.415
RPA class
I (reference)	1	--	--
II	0.00	0.00 to ∞	1.000
III	0.00	0.00 to ∞	1.000
Primary tumor status (uncontrolled vs. controlled)	1.12	0.28 to 4.57	0.869
Extracranial metastases (present vs. absent)	2.05	0.51 to 8.34	0.314
Number of BM (>3 vs. ≦3)	0.89	0.22 to 3.61	0.869
Size of largest BM (mm)	1.07	0.99 to 1.15	0.091
Hemorrhagic BM (yes vs. no)	6.00	0.68 to 52.90	0.107
Total dose (>40 Gy₂ vs. ≦40 Gy₂)	1.07	0.28 to 4.05	0.925
EGFR TKI during RT (yes vs. no)	0.89	0.24 to 3.30	0.864
Type of EGFR TKI^§ (erlotinib vs. gefitinib)	1.67	0.20 to 14.05	0.639
Chemotherapy during RT (yes vs. no)	2.00	0.36 to 11.06	0.427

Abbreviations: OR odds 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.

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