Table 2.

Associated factors with CNS metastasis development

N = 293	CNS Metastasis 12 months % (95% IC)	CNS Metastasis 24 months % (95% IC)	p Univariate Analysis	RR (95% CI)	p Multivariate Analysis
Age
<60 years	20 (14.2–25.8)	36 (20.2–51.6)	0.79
≥60 years	22 (16.1–27.8)	22 (16.1–27.8)
Gender
Female	21 (13.6–27.3)	31 (12.9–48.1)	0.86
Male	22 (16.1–27.9)	33 (18.8–46.2)
Smoking History
Negative	24 (18.2–29.9)	36 (18.6–53.9)	0.22
Positive	19 (13.1–24.8)	26 (12.3–39.7)
Histology
Adenocarcinoma	28 (22.1–33.8)	31 (23.1–38.8)	0.0002	5.2 (1.002–29)	0.05
*Others	7.8 (3.9–11.7)	29 (3.5–54.4)
CEA ≥ 40 ng/mL
Negative	12 (8–15.9)	24 (11.8–35.3)	<0.001	11.4 (1.7–74)	0.01
Positive	61 (45.4–76.8)	61 (45.4–76.8)
EGFR***
Positive	57 (56.6–57.3)	57 (56.6–57.3)	0.2
Negative	45 (44.6–45.3)	45 (44.6–45.3)

The endpoint for univariate analysis was CNS metastasis at 24 months.

CNS: Central Nervous System.

RR (95% CI): Relative Risk (95% Confidence Interval).

*Others: Squamous, Giant Cells, Undifferentiated.

CEA: Carcinoembryonic Antigen.

***: Tissue expression was determined only in 85 different

primary tumor samples (see text).