Table 3.

Cases and controls, and OR for cholangiocarcinoma associated with smoking, alcohol drinking, and XRCC1 and OGG1 polymorphisms

	Cases		Controls
Variables	n	Per cent	n	Per cent	OR*	OR†	95% CI‡	p Value
XRCC1 G399A polymorphisms§
GG	62	38.8	149	44.0	1.0	1.0
GA	94	58.8	169	49.9	1.3	1.2	0.76 to 1.94	0.43
AA	4	2.5	21	6.2	0.5	0.4	0.10 to 1.62	0.20
OGG1 C326G polymorphisms¶
CC	34	23.4	95	28.9	1.0	1.0
CG	109	75.2	229	69.6	1.4	1.2	0.70 to 2.07	0.49
GG	2	1.4	5	1.5	1.2	0.7	0.10 to 5.11	0.75
Cigarette smoking
Non-smoker	92	42.0	230	52.5	1.0	1.0
Smoker	127	58.0	208	47.5	2.7	1.9	0.94 to 4.01	0.07
Units of alcohol per month of all alcohol consumption
Non-drinker	57	26.0	254	58.0	1.0	1.0
<14	79	36.1	92	21.0	5.2	5.2	2.74 to 9.95	<0.001
≥14	83	37.9	92	21.0	6.7	7.6	3.67 to 15.72	<0.001

*Crude OR from matched case–control analysis.

†Adjusted OR from matched case–control analysis (adjusted for all other variables in the table).

‡95% CI for OR.

§DNA samples for XRCC1 genotyping were successfully carried out for 160 out of 175 cases, and for 339 out of 350 controls.

¶DNA samples for OGG1 genotyping were successfully carried out for 145 out of 175 cases, and for 329 out of 350 controls.