ABSTRACT Lung cancer is a multifactorial carcinoma with diverse heterogeneity. Genetic variations in drug-metabolizing enzymes may lead to defective detoxification and clearance of carcinogenic compounds. The high-order gene-gene interaction has been carried out between different genotypes of Phase II detoxification genes (NQO1, SULT1A1, NAT2, and EPHX1). Our results depict the genetic combination of SULT1A1 R 213 H with NAT2 × 5B L 161 L, SULT1A1 R 213 H with NAT2 × 5C K 268 R, EPHX1 H 139 R and NAT2 × 5B L 161 L exhibit a protective effect towards lung cancer risk. Further, the triple combinations of NQO1 P 187 S, EPHX1 Y 113 H, and EPHX1 H 139 R; NQO1 P 187 S, EPHX1 Y 113 H, and NAT2 × 6 R 197 Q; NQO1 P 187 S, EPHX1 Y 113 H, and NAT2 × 7 G 286 E; SULT1A1 R 213 H, EPHX1 H 139 R, and NAT2 × 7 G 286 E suggested a two-fold increased risk of lung cancer for subjects. Genetic polymorphisms of phase II detoxifying genes (NAT2, NQO1, EPHX1, SULT1A1) are prognostic markers for lung cancer.