Table 1. The distributions of demographical characteristics in 1200 controls and 876 male patients with oral cancer.

Variable	Controls (N = 1200)	Patients (N = 876)	p value
Age (yrs)
	53.90 ± 10.02	54.80 ± 11.03	p = 0.06
Betel quid chewing
No	1001 (83.4%)	175 (20.0%)
Yes	199 (16.6%)	701 (80.0%)	p <0.01*
Cigarette smoking
No	564 (47.0%)	92 (10.5%)
Yes	636 (53.0%)	784 (89.5%)	p <0.01*
Alcohol drinking
No	963 (80.3%)	388 (44.3%)
Yes	237 (19.8%)	488 (55.7%)	p <0.01*
Stage
I+II		435 (49.7%)
III+IV		441 (50.3%)
Tumor T status
T1+T2		512 (58.4%)
T3+T4		364 (41.6%)
Lymph node status
N0		597 (68.2%)
N1+N2+N3		279 (31.8%)
Metastasis
M0		868 (99.1%)
M1		8 (0.9%)
Cell differentiation
Well differentiated		141 (16.1%)
Moderately or poorly differentiated		735 (83.9%)

Mann-Whitney U test or Fisher’s exact test was used between healthy controls and patients with oral cancer.

* p value < 0.05 as statistically significant.