Background: Alcohol consumption is one of the major risk factors of the upper aerodigestive tract (UADT) cancers, and combined cancers are frequently discovered in the patients with UADT cancer. The association between esophageal cancer and alcohol-related metabolizing enzymes is well studied, but only a few examinations about the association between head and neck cancer and the enzymes were performed.
Methods: Fifty-two patients with UADT cancer (head and neck cancer in 25, esophageal cancer in 19, and multiple cancers in 8) were examined in the alcohol habit and in the polymorphisms of aldehyde dehydrogenase 2 (ALDH2) and cytochrome P-4502E1.
Results: Patients with multiple cancers had significantly higher ethanol consumption than the other two groups (p < 0.001). The frequency of ALDH2*1/2*2 heterozygote was significantly lower (p = 0.009) in patients with head and neck cancer (5/25) than patients with esophageal cancer (11/19). The allele frequency of P-4502E1 did not show a significant difference between the groups (p = 0.700).
Conclusions: These results demonstrated the difference in the frequency of ALDH2 heterozygote between the patients with esophageal cancer and patients with head and neck cancer.