Abstract Background Superoxide dismutase (SOD) is an antioxidant enzyme that acts to degrade superoxide, a major causative factor in carcinogenesis. We assessed associations between serum SOD activities and the incidence of esophageal cancer in a case–control study nested in the Japan Collaborative Cohort (JACC) Study. Methods At baseline, 39 242 subjects donated serum samples. Participants who were diagnosed with esophageal cancer during follow-up were regarded as cases. Conditional logistic regression models were used to evaluate odds ratios (ORs) for esophageal cancer incidence associated with serum SOD activity. Results The present study included 27 cases and 80 controls. Serum SOD activity was associated with risk of esophageal cancer (P for trend = .040) and the third tertile of SOD level showed the highest risk compared to the first (OR = 7.41, 95% confidence interval CI = 1.14–48.35). Limiting subjects to those followed-up over 3 years, all trends remained unchanged (P for trend = .044), with the third tertile still showing the highest risk compared to the first (OR = 7.63, 95% CI = 1.06–55.23). Conclusions Our findings suggest that serum SOD activity may be associated with the risk of esophageal cancer.
ADACHI et al. (Sat,) studied this question.