Antioxidants and cancers of the esophagus and gastric cardia

Antioxidant vitamins have attracted considerable attention in previous stud ies of esophageal squamous-cell carcinoma, but dietary studies of adenocarc inoma of the esophagus and gastric cardia remain sparse. Treating these tum ors as distinct diseases, we studied intakes of vitamin C, betacarotene and alpha-tocopherol in a nationwide population-based case-control study in Sw eden, with 185, 165, and 258 cases of esophageal adenocarcinoma, esophageal squamous-cell carcinoma, and gastric cardia adenocarcinoma, respectively, and 815 controls. Subjects with a high parallel intake of vitamin C, beta-c arotene, and alpha-tocopherol showed a 40-50% decreased risk of both histol ogical types of esophageal cancer compared with subjects with a row paralle l intake. Antioxidant intake was not associated with the risk of gastric ca rdia adenocarcinoma. Separately, vitamin C and beta-carotene reduced the ri sk of esophageal cancers more than alpha-tocopherol. We found that antioxid ant intake is associated with similar risk reductions for both main histolo gical types of esophageal cancer. Our findings indicate that antioxidants d o not explain the diverging incidence rates of the 2 histological types of esophageal cancer. Moreover, our data suggest that inverse associations wit h esophageal squamous-cell carcinoma and adenocarcinoma may be stronger amo ng subjects under presumed higher oxidative stress due to smoking or gastro esophageal reflux, respectively. Our results may be relevant for the implem entation of focused, cost-effective preventive measures. (C) 2000 Wiley-Lis s, Inc.