Table 3. Cox proportional-hazards analysis of associations between allelic variants and overall survival status among colorectal cancer patients based on tumor location.

	Colon						Rectum
Variables	Patients	Events	MSM	HR (95% CI)a	P	FDR	Patients	Events	MSM	HR (95% CI)a	P	FDR
GSTM1
Null	171	95	48.1	1 (reference)			115	66	48.5	1 (reference)
Present	112	57	48.9	0.83 (0.59–1.15)	0.262	0.689	93	50	56.7	0.82 (0.56–1.19)	0.287	0.689
GSTT1
Null	149	79	49.1	1 (reference)			100	54	55.8	1 (reference)
Present	134	73	47.1	1.21 (0.88–1.68)	0.240	0.689	108	62	48.5	1.12 (0.77–1.62)	0.559	0.917
GSTP1 Ile105Val
Ile/Ile	191	102	48.1	1 (reference)			145	81	49.5	1 (reference)
Ile/Val + Val/Val	92	50	48.6	1.12 (0.80–1.58)	0.506	0.917	63	35	49.0	1.07 (0.72–1.59)	0.745	0.917
XRCC1 Arg399Gln
Arg/Arg	159	75	57.1	1 (reference)			90	51	57.2	1 (reference)
Arg/Gln + Gln/Gln	124	77	36.4	1.25 (0.90–1.73)	0.181	0.689	118	65	47.7	0.98 (0.68–1.42)	0.910	0.917
XRCC3 Thr241Met
Thr/Thr	263	142	48.1	1 (reference)			196	111	49.0	1 (reference)
Thr/Met	20	10	49.0	1.06 (0.56–2.01)	0.866	0.917	12	5	67.4	0.95 (0.38–2.39)	0.917	0.917
XPD Lys751Gln
Lys/Lys	234	125	48.0	1 (reference)			170	91	51.6	1 (reference)
Lys/Gln + Gln/Gln	49	27	49.1	1.10 (0.72–1.67)	0.667	0.917	38	25	44.9	1.87 (1.18–2.95)	0.007	0.084

^aAdjusted for age, sex, and tumor-node-metastasis stage.

MSM: median survival month; HR: hazard ratio; CI: confidence interval; FDR: false discovery rate.