A polymorphism within ErbB4 is associated with risk for hepatocellular carcinoma in Chinese population

Table 1 Demographic characteristics of the hepatocellular carcinoma case and control groups

Characteristics	Case		Control		P value
	n = 270	Frequency (%)	n = 270	Frequency (%)
Age, (yr) (mean ± SD)	50.3 ± 9.2		50.7 ± 9.4		0.91a
Gender
Male	187	69.3	190	70.4	0.78b
Female	83	30.7	80	29.6
Smoking status
Smoker	79	29.3	85	31.5	0.57b
Non-smoker	191	70.7	185	68.5
Drinking status
Drinker	120	44.4	116	43.0	0.73b
Non-drinker	150	55.6	154	57.0
Tumor stages
Ia + Ib	193	71.5
IIa + IIb	58	21.5
IIIa + IIIb	19	7.0
HBsAg, n (%)
Positive	201	74.4	26	9.6	< 0.0001b
Negative	69	25.6	244	90.4

^aTwo-sided two-sample t-tests.

^bχ² tests. HBsAg: Hepatitis B surface antigen.