Polymorphisms of glutathione S-transferase genes and survival of resected hepatocellular carcinoma patients

Table 6 Modulating effects of smoking on hepatocellular carcinoma overall survival by GSTO2: rs7085725 or GSTP1: rs4147581 genotypes

SNP and variables	Death/total	HR (95%CI)	P value
In patients with WW genotype of GSTO2: rs7085725
Smoking behavior
No smoking	52/119	1 (ref)
Smoking	29/57	1.04 (0.82-1.31)	0.757
Smoking quantity (packs-year)1
0	52/119	1 (ref)
> 0 and < 20	20/45	1.06 (0.82-1.37)	0.667
≥ 20	9/12	0.99 (0.76-1.30)	0.956
In patients with WV + VV genotypes of GSTO2: rs7085725
Smoking behavior
No smoking	19/25	1 (ref)
Smoking	11/33	1.52 (1.02-2.26)a	0.042a
Smoking quantity (packs-year)1
0	19/25	1 (ref)
> 0 and < 20	9/11	1.42 (0.93-2.16)	0.106
≥ 20	2/2	2.07 (1.13-3.76)	0.018a
In patients with WW genotype of GSTP1: rs4147581
Smoking behavior
No smoking	35/61	1 (ref)
Smoking	22/42	0.95 (0.72-1.24)	0.697
Smoking quantity (packs-year)1
0	35/61	1 (ref)
> 0 and < 20	15/33	0.97 (0.71-1.31)	0.824
≥ 20	7/9	0.95 (0.71-1.28)	0.754
In patients with WV + VV genotypes of GSTP1: rs4147581
Smoking behavior
No smoking	36/83	1 (ref)
Smoking	18/28	1.27 (0.95-1.69)	0.101
Smoking quantity (packs-year)1
0	36/83	1 (ref)
> 0 and < 20	14/23	1.27 (0.93-1.74)	0.128
≥ 20	4/5	1.16 (0.81-1.66)	0.426

¹To calculate pack-years of smoking, the average of number of cigarettes smoked per day was divided by 20 to give packs per day and multiplied by the total number of years of smoking.

^aP < 0.05 was considered statistically significant. WW: Homozygous wild-type genotype; WV: Heterozygous genotype; VV: Homozygous variant genotype; SNP: Single nucleotide polymorphisms.