Table 1. Characteristics of healthy volunteers.

		Healthy volunteer control	NSCLC pts in first-line therapy	P-value	NSCLC pts in second-line therapy	P-value
N		30	53		48
Sex	Female	16 (46.7%)	24 (45.3%)	0.48	21 (43.8%)	0.41
Age yr. (mean ± S.D.)		63.8 ± 7.0	65.6 ± 9.3	0.42	64.5 ± 11.8	0.85
Smoking	Never	11 (36.7%)	22 (41.5%)	0.66	21 (43.8%)	0.54
	Smoker	19 (73.3%)	31 (58.5%)		27 (56.3%)

The characteristics of the healthy volunteers in this study. Data are presented as numbers. P-values were calculated using the chi-square test or Student's t-test in categorical variables or continuous variables, respectively. NSCLC: non-small cell lung cancer; pts: patients.