Читать книгу Hypopharyngeal Cancer - Группа авторов - Страница 20

Not all alcohol drinkers develop hypopharyngeal cancer indicating a role of host susceptibility factors in cancer development. Researchers have recommended that genetic polymorphisms might explain individual variations in susceptibility to hypopharyngeal cancer [61]. Two enzymes are essentially involved in alcohol metabolism. Alcohol is initially oxidised to acetaldehyde by alcohol dehydrogenase 1B (ADH1B) and then to acetic acid by aldehyde dehydrogenase 2 (ALDH2). The genes encoding both enzymes exhibit polymorphism and ethnic variations. Amino acid coding single nucleotide polymorphisms of ADH1B and ALDH2 are well known, and the ADH1B*1/*1 and ALDH2*2 alleles of these SNPs have marked enzymatic activities resulting in the accumulation of toxic acetaldehyde [62]. In a genotype analysis of 85 Japanese male patients with hypopharyngeal cancer, it was concluded that heavy drinkers with the ALDH2*2 allele were associated with a poor outcome [63], and further studies are recommended to confirm this hypothesis.