Table 3.

Univariate and multivariate analyses of BM incidence and recurrence. OR: odds ratio; 95% CI: 95% confidence interval; BM: brain metastasis; age: <65 versus ≥65; sex female versus male; ethnicity: Caucasian versus non Caucasian; smoking status: smoker versus non-smoker; primitive tumor local treatment: surgery or radiation therapy versus no local treatment; Mutation status: EGFR-mutant versus KRAS-mutant versus KRAS and EGFR wild-type tumors; WT: wild-type; BM local treatment: any local treatment (whole brain radiation therapy, surgery or radiosurgery) versus no local treatment; number of metastases: one metastasis versus several metastases; NA: not applicable; *: significant p-value.

Characteristics	Univariate Analyses			Multivariate Analyses
	OR	95% CI	p-Value	OR	95% CI	p-Value
BM Incidence
Age	0.996	0.965–1.027	0.799	0.998	0.965–1.032	0.897
Sex	1.193	0.592–2.404	0.621	0.988	0.440–2.219	0.977
ECOG PS	1.041	0.391–2.769	0.936	NA	NA	NA
Smoking status	0.767	0.345–1.706	0.515	0.489	0.178–1.339	0.164
Primary tumor local treatment	1.384	0.541–3.545	0.498	NA	NA	NA
Mutation status			0.060			0.031 *
EGFR mutant versus EGFR WT	6.488	1.383–30.443	0.018 *	8.745	1.743–43.881	0.008 *
KRAS mutant versus KRAS WT	1.148	0.556–2.369	0.710	1.082	0.505–2.318	0.840
BM Recurrence after Local Treatment
Age	0.987	0.944–1.032	0.562	0.975	0.929–1.023	0.296
Sex	1.037	0.408–2.636	0.939	0.983	0.322–3.000	0.976
ECOG PS	0.510	0.137–1.898	0.315	NA	NA	NA
Smoking status	0.939	0.314–2.810	0.911	0.626	0.153–2.565	0.515
Mutation status			0.054			0.029 *
EGFR mutant versus EGFR WT	0.853	0.249–2.921	0.801	0.970	0.245–3.845	0.966
KRAS mutant versus KRAS WT	0.284	0.100–0.807	0.018 *	0.234	0.078–0.699	0.009 *
Synchronous or metachronous BM	1.786	0.712–4.480	0.216	NA	NA	NA
BM local treatment	0.709	0.236–2.133	0.541	NA	NA	NA
Number of metastases	0.962	0.390–2.370	0.932	NA	NA	NA