Aims: Most of the acetaldehyde, a recognized animal carcinogen, generated during alcohol metabolism is eliminated by liver mitochondrial aldehyde dehydrogenase 2 (ALDH2). More than 40% of Japanese people have the inactive form of ALDH2, and inactive ALDH2 is a risk factor for multiple cancer of the esophagus, as well as head and neck cancer. Possible associations between pancreatic cancer and ALDH2 gene polymorphism, as well as between colon cancer and ALDH2 gene polymorphism, in conjunction with smoking and/or drinking habits, were examined in a Japanese population.
Methods: Patients with pancreatic cancer (n = 187) and with colon cancer (n = 49) were examined. The drinking (5 g ethanol consumption/day) and/or smoking habits as well as ALDH2 gene polymorphism were examined. The age-matched control subjects were recruited in the NILS Longitudinal Study of Aging (LSA).
Results: Aging, smoking and inactive ALDH2, but not alcohol, are independent risk factors for pancreatic cancer. The frequency of smoking habits tended to be higher in patients with colon cancer compared with the patients without cancer. However, age, body mass index or the distribution of ALDH2 genotypes did not differ significantly among the patients with colon cancer, colon polyps and others.
Conclusions: Inactive ALDH2 is an independent risk factor for pancreatic cancer, but inactive ALDH2 might not be a risk for colon cancer.