The purpose of this study was to investigate the relationship between lung cancer cases in Japan and variant alleles of cytochrome P450 (CYP) 2A6 (CYP2A6*4), CYP2A13 (CYP2A13*1-*10), CYP4B1 (CYP4B1*1-*7), sulfotransferase 1A1 (SULT1A1*2), glutathione S-transferase M1 (GSTM1 null), and glutathione S-transferase T1 (GSTT1 null).
MDR analysis identified two distinct predictor models for the risk of lung cancer in smokers (tobacco chewing, EPHX1 Tyr113His, and SULT1A1Arg213His) and non-smokers (CYP1A1*2A, GSTP1 Ile105Val and SULT1A1Arg213His) with testing balance accuracy (TBA) of 0.6436 and 0.6677 respectively.
Compared with the SULT1A1*1/SULT1A1*1 genotype the variant SULT1A1 genotype (SULT1A1*1/SULT1A1*2 or SULT1A1*2/SULT1A1*2) was associated with a significantly increased lung cancer risk in cases (p = 0.027).
Our results, which are against the original hypothesis, demonstrate that the variant SULT1A1 638A allele is associated with susceptibility to lung cancer in relation to tobacco smoking.
Furthermore, the SULT1A1Arg213His polymorphism was associated with an increased risk of lung cancer in both females and males in the dominant model (females: OR=1.72, 95%CI=1.29-2.27, P=0.00; males: OR=1.46, 95%CI=1.19-1.78, P=0.00).