Table 5.

Association and Stratification analyses between the combined genotypes of MGMT polymorphisms and SCCHN risk

Variables	n (case/control)	Combined genotypes (case/control)a				Crude OR (95% CI)	Adjusted OR (95% CI)b
		0-2 risk genotypes		3-4 risk genotypes
		n	%	n	%
All subjects	721/1,234	289/567	40.1/46.0	432/667	59.9/54.0	1.27 (1.06-1.53)	1.27 (1.05-1.53)
Age (years)
≤ 45	105/195	40/104	38.1/53.3	65/91	61.9/46.7	1.86 (1.14-3.01)	1.81 (1.11-2.96)
46-60	334/532	134/233	40.1/43.8	200/299	59.9/56.2	1.21 (0.90-1.62)	1.21 (0.91-1.61)
> 60	282/507	115/230	40.8/45.4	167/277	59.2/54.6	1.16 (0.88-1.54)	1.16 (0.86-1.58)
Sex
Female	181/320	72/152	39.8/47.5	109/168	60.2/52.5	1.37 (0.95-1.98)	1.33 (0.91-1.94)
Male	540/914	217/415	40.2/45.4	323/499	59.8/54.6	1.24 (1.00-1.54)	1.24 (1.00-1.55)
Smoking status
Never	188/371	73/168	38.8/45.3	115/203	61.2/54.7	1.30 (0.91-1.86)	1.30 (0.91-1.87)
Ever	533/863	216/399	40.5/46.2	317/464	59.5/53.8	1.26 (1.01-1.57)	1.25 (1.01-1.56)
Drinking status
Never	158/374	65/173	41.1/46.3	93/201	58.9/53.7	1.23 (0.84-1.79)	1.24 (0.85-1.81)
Ever	563/860	224/394	39.8/45.8	339/466	60.2/54.2	1.28 (1.03-1.59)	1.29 (1.04-1.60)
Tumor site
Oral cavity	222/1,234	93/567	41.9/46.0	129/667	58.1/54.0	1.18 (0.88-1.58)	1.18 (0.88-1.58)
Oropharynx	326/1,234	121/567	37.1/46.0	205/667	62.9/54.0	1.44 (1.12-1.85)	1.45 (1.12-1.87)
Larynxc	173/1,234	75/567	43.4/46.0	98/667	56.6/54.0	1.11 (0.81-1.53)	1.10 (0.80-1.53)

^aThe number represents the numbers of risk genotypes; the risk genotypes used for the calculation were 16195CC, 16286CC, 45996GT+TT, and 46346CA+AA genotypes).

^bORs were adjusted for age, sex, smoking status, and alcohol use in a logistic regression model.

^cIncluded both hypopharynx and larynx.