Table 4.

Association between methylation and subjects’ demographic characteristics

Demographic characteristics		p16INK4a		P-value	RASSF1A		P-value	MGMT		P-value
		M 60	U 24		M 41	U 43		M 52	U 32
Gender	Male	51	20	1.0000	33	38	0.3758	41	30	1.0000
	Female	9	4		8	5		7	6
Age	<55	24	7	0.4552	15	16	1.0000	19	12	1.0000
	>55	36	17		26	27		33	20
Smoking Number of years in use	Non-smokers	10	9	0.029	9	10	0.265	9	10	0.03
	< 15	17	9		16	10		13	13
	4>15	33	6		16	23		30	9
Differentiation	Well	17	4	0.004	8	13	0.0007	9	12	0.0536
	Moderately	22	18		14	26		25	15
	Poorly/undifferentiated	21	2		19	4		18	5
Stage	I/ II	16	15	0.0029	7	24	0.0001	14	17	0.0206
	III/ IV	44	9		34	19		38	15