Table 3. Univariate analysis of quantitative factors.

	Benign	Malignant	p Value
Age (year)	49.2±11.74	62.4±9.56	0.000
Maximal diameter (cm)	1.63±0.64	2.04±0.59	0.002
CEA (ng/ml)	2.21±0.99	6.72±14.13	0.089*
Cyfra21-1 (ng/ml)	2.18±0.83	2.85±1.11	0.004

^*Data of CEA did not achieve the homogeneity of variance, P value of rank-sum test >0.05, indicated no difference between groups. Result may relate to disperse distribution of value of CEA in malignant group, and could be positive after sum of case enlardged.