Table 1. Subject characteristics of lung cancer cases and cancer-free controls.

Subject characteristics	Lung cancer status
	Lung cancer (n=46)	No lung cancer (BC) (n=90)	P	No lung cancer (SNC) (n=90)	P
Gender (male %)	32 (69.6)	56 (62.2)	0.51	64 (71.1)	1
Age† (years), median [range]	63.0 [51.9–74.5]	56.8 [50.9–69.7]	0.001	55.8 [50.6–70.0]	<0.001
Smoking status‡ (current/former, %)	24/22 (52.2/47.8)	54/36 (60.0/40.0)	0.49	54/36 (60.0/40)	0.49

^†, at blood draw; ^‡, at randomization. Smokers: at least 25 years smoking of at least 15 cigarettes per day, or at least 30 years smoking of at least 10 cigarettes per day, including former smokers. Former smokers are those who had stopped smoking not more than 10 years before invitation to screening. BC, baseline control group; SNC, suspicious nodules control group.