Site disparities in apoptotic variants as predictors of risk for second primary malignancy in patients with squamous cell carcinoma of the head and neck

Table 4 SPM risk associated with combined FAS/FASL variant genotypes after index OPC and non-OPC, stratified by smoking and alcohol

Variables	Low-risk group^a		High-risk group^b		cHRs^c, (95 % CI), P	aHRs^d (95 % CI), P
Variables	No.	%	No.	%	Low-risk group (ref.) vs. High-risk group	Low-risk group (ref.) vs. High-risk group
OPC	575	76.5	177	23.5
Smoking
Ever	325	56.5	104	58.8	1.4 (0.5–3.3), 0.722	1.4 (0.6–3.4), 0.787
Never	250	43.5	73	41.2	18.9 (1.3–330.2), 0.032	20.0 (1.2–327.0), 0.028
Alcohol
Ever	421	73.2	128	72.3	1.3 (0.3–3.7), 0.823	1.4 (0.5–3.8), 0.822
Never	154	26.8	49	27.7	1.9 (0.3–17.2), 0.887	1.8 (0.2–16.1), 0.867
Non-OPC	614	79.0	163	21.0
Smoking
Ever	455	74.1	125	76.7	2.1 (1.1–4.2), 0.013	2.3 (1.2–4.4), 0.011
Never	159	25.9	38	23.3	0.2 (0.1–1.4), 0.346	0.1 (0.0–1.2), 0.323
Alcohol
Ever	426	69.4	124	76.1	2.3 (1.1–3.9), 0.022	2.2 (1.2–4.1), 0.019
Never	188	30.6	39	23.9	0.5 (0.2–4.3), 0.798	0.6 (0.1–4.1), 0.801

^aLow-risk group: 0–2 variant genotypes
^bHigh-risk group: 3–4 variant genotypes
^cCrude HRs
^dHRs were adjusted for age, sex, ethnicity, smoking, alcohol, index cancer stage, and treatment