Table 2.

The demographic and clinical variables of an internal testing set of patients with either malignant or benign SPNs

	67 Patients with malignant SPNs (stage I and II NSCLC)	69 Patients with benign SPNs
Age, Median (SD)	66.4 (7.9)	64.9 (SD 8.5)
Sex
Female	24 (35.8%)	23 (33.3%)
Male	43 (64.2%)	46 (66.7%)
Race
African American	19 (28.4%)	20 (28.9%)
White	48 (71.6%)	49 (70.1%)
Nodule size (cm)
Median (SD)	2.5 (1.6)	1.8 (1.7)
Range	0.5–4.5	0.1–3.9
Pack-years, Median (SD)	36.9 (SD 25.7)	34.6 (SD 32.5)
Stages
stage I	45 (67.2%)
stage II	22 (32.8%)
Histological types of NSCLC
AC	30 (44.8%)
SCC	31 (46.3%)
Others	6 (8.9%)

Abbreviations: SPNs, solitary pulmonary nodules; SD, standard deviation; NSCLC, non-small-cell lung cancer; AC, adenocarcinoma; SCC, squamous cell carcinoma.