Table 1.

Characteristics of patients with pulmonary benign nodules, patients with malignant nodules, and healthy controls.

	Healthy controls	Pulmonary benign	Pulmonary malignant
		nodules	nodules
No. of subjects	20	15	17
Gender	Male	Male	Male
Age range (median)	29–50 (38)	33–79 (59)	49–67(60)
Smoking habits	Smokers 6	Smokers 9	Smokers 17
	Non-smokers 14	Non-smokers 6	Non-smokers 0
Nodule size (average)		1.9 cm	2.2 cm
Histological type			Squamous cell carcinoma
Cancer stage			Ⅰ