Ung thư tỷ lệ Ascorbic acid 120 mg / ngày Molybdenum 30 ung thư tử vong mg / ngày Riboflavin mg / ngày ung thư tỷ lệ Niacin 40 mg / ngày ung thư tử vong 26 vitamin và erals tỷ lệ mắc ung thư min-(liều lượng khác nhau) | Table 17-3 continued Randomized Controlled Chemoprevention Trials for Esophageal Cancer Candidate Risk Cohort Intervent. Form and Dose Endpoint Risk Est. Comments Agent s Multinutrient57 29 584 Period Residents of a high- years Ascorbic acid 120 Cancer incidence 95 CI to Squamous cell carcinoma. co n t Mutinutrient58 33I8 risk global region Cytologically- 6 years mg day Molybdenum 30 Mg day Riboflavin mg day Niacin 40 mg day 26 vitamins and min- Cancer mortality Cancer incidence Cancer mortality Cancer incidence to to to to Squamous cell carcinoma. Multinutrient76 6I0 detected squamous dysplasia Residents of a high- months erals various doses Retinol 50 000 IU Spectrum of histo- N A Prevalence of esophagitis lN number randomized risk global region week Riboflavin 200 mg week Zinc 50 mg week Cl confidence interval N A not available logically-defined lesions with or without atrophy or dysplasia found to be nearly the same in the placebo group 45 and the vita-min zinc treated group 49 . 338 Chapter 17 Chemoprevention for Gastrointestinal Neoplasia 339 minimally reduced esophageal cancer incidence RR 95 CI to and mortality RR 95 CI to rates after years of selenium 50 mg day as selenized yeast fi-carotene 15 mg day and a-tocopherol 30 mg day .57 In the smaller Dysplasia Trial subjects with cytologically-detected dysplasia at baseline n 3318 had similar risks for incident RR 95 CI to and fatal RR 95 CI to esophageal cancer regardless of whether they received daily supplementation with 26 vitamins and minerals including sodium selenate 50 mg day vs placebo over the 6-year intervention Antioxidant Vitamins Vitamins A C and E as well as their biochemical precursors may prevent esophageal and or other cancers by neutralizing free radicals and blocking carcinogen formation. Retinoids are also thought to inhibit .