Consistent with the results of case control studies, prospective studies in cancer-free alcoholics have also shown that the relative hazard for future upper aerodigestive tract (UADT) cancers in low-activity ALDH2 heterozygotes is approximately 12 times higher than in individuals with active ALDH2 [15]. (The UADT includes the oral cavity, pharynx, larynx, and esophagus.) In addition, alcohol consumption in low-activity ALDH2 heterozygotes has been associated with other cancer-related outcomes, including the presence of multiple areas of esophageal dysplasia (i.e., premalignant lesions) and multiple independent UADT cancers [13].
