Now that the human genome has been sequenced, we consider that combinations of 3 to 10 million polymorphic loci scattered throughout the genome contribute to individual differences. Genetic polymorphism analysis is useful for the made-to-order medical treatment of patients and the prevention of disease onset in normal healthy individuals. Individually-tailored disease prevention based on findings such as genetic polymorphism analysis results can be grasped by the concept of evidence-based prevention (EBP). In this paper we outline cytochrome P450 (CYP) 1A1 and 2E1 polymorphism-related differences in metabolic activation of carcinogens in relation to the risk of lung cancer, and explain single nucleotide polymorphism (SNP). We also compare the reports to date on SNP types in CYP1A1 and CYP2E1 in relation to the risk of lung cancer with our study results, examine survival rates of lung cancer patients by CYP1A1 or CYP2E1 genotype and discuss the applicability of SNP research to EBP.