SERUM MICRONUTRIENTS AND PROSTATE-CANCER IN JAPANESE-AMERICANS IN HAWAII

Numerous dietary studies and several serum micronutrient studies have produced equivocal results on the relation of vitamins A and E to pros tate cancer risk, To evaluate this association further, we conducted a nested case-control study in a cohort of 6860 Japanese-American men e xamined from 1971 to 1975, At the time of examination, a single blood specimen was obtained, and the serum was frozen, After a surveillance period of more than 20 years, 142 tissue-confirmed incident cases of p rostate cancer were identified, Their stored sera and those of 142 mat ched controls were measured by highperformance liquid chromatography f or the following: total carotenoids, lutein, zeaxanthin, beta-cryptoxa nthin, lycopene, alpha-carotene, beta-carotene, total retinoids, retin ol, total tocopherols, alpha-tocopherol, delta-tocopherol, and gamma-t ocopherol. Odds ratios for prostate cancer, based on quartiles of seru m micronutrient levels, were determined using conditional logistic reg ression analysis, The odds ratio for the highest quartiles were 1.8 (9 5% confidence interval, 0.9-3.9) for beta-cryptoxanthin, 1.6 (0.8-3.5) for beta-carotene, 0.8 (0.4-1.5) for retinol, and 0.7 (0.3-1.5) for g amma-tocopherol, but none of the differences was statistically signifi cant, For the other micronutrients, the results were also unremarkable , The findings of this study indicate that none of the micronutrients is strongly associated with prostate cancer risk.