Table 2.

Median survival and time from primary diagnosis to brain metastasis by gene status and tyrosine kinase inhibition

Factor	n (%)	MS, mo	IQR, mo	P values vs EGFR & ALK−;* vs no TKI†	Mean time: primary diagnosis to BM, mo	P value vs EGFR & ALK−‡
Adenocarcinoma overall	1521	15	14–17		16
Alteration status unknown	705 (46)	12	5–25	.12*	19	.08‡
Alteration status known	816 (54)	19	7–40		13
EGFR & ALK−	284 (35)	14	10	ref*	10	ref‡
EGFR+	235 (29)	23	20–28	<.01*	15	.02‡
No TKI before BM	161 (69)	30	12–47	ref†
Received TKI before BM	74 (31)	17	9–26	<.01†
ALK+	86 (10)	45	32–62	<.01*	20	<.01‡
No TKI before BM	53 (61)	45	31-NR	ref†
Received TKI before BM	33 (39)	NR	5-NR	.43†
KRAS+	211 (26)	12	5–32	.84*	13	.25‡

Abbreviations: MS = median survival; NR = not reached; ref = reference; TKI = tyrosine kinase inhibition.

Percentages (%) are within the subgroup whose total is above and 1 column left. For example, 211/816 = 26% of patients with known alterations were KRAS+, and 161/235 = 69% of patients who were EGFR+ did not receive TKI before BM.

Forty-five patients had invalid dates and were excluded for metastasis time evaluation.

^*P values are from log-rank tests comparing survival distributions between each alteration group—EGFR+, ALK+, KRAS+, and unknown—and the EFGR & ALK− group as reference.

^†P values are from log-rank tests comparing survival distributions between each TKI group, within EGFR+ and ALK+ subgroups, respectively.

^‡P values are from Wilcoxon rank sum tests comparing the time from primary diagnosis to BM between each alteration group and the EGFR & ALK− group as reference. TKI could be initiated at any time between primary diagnosis and BM, so time from primary diagnosis to BM was compared for TKI with time-dependent analyses (results not presented in table).