beta-carotene and Carcinoma--Transitional-Cell

A range of plausible biological mechanisms support preventive effects of micronutrients in bladder cancer. So far, however, results from the few epidemiological studies on the relation have been inconsistent, with no clear associations found.. To evaluate the association between total, dietary, and supplemental intake of beta-carotene, folate, vitamins C and E, and risk of urothelial carcinoma (UC) and to explore whether the association differs with smoking status.. The association was evaluated in the Danish Diet, Cancer and Health Study, comprising 55,557 men and women aged 50-64 yr at inclusion with no previous cancer diagnosis.. At baseline, all participants completed a detailed food frequency questionnaire including information on consumption of vitamin C, E, folate, and beta-carotene from diet and supplements. Incidence rate ratios (IRRs) of UC were calculated using Cox proportional hazards models.. During a median of 10.6 yr of follow-up, 322 UC cases were diagnosed. Vitamin C, E, and folate showed no association with UC, regardless of source. There was a significantly lower risk of disease with dietary beta-carotene consumption (IRR: 0.82; 95% confidence interval [CI]: 0.69-0.98) and a borderline significant lower risk with total beta-carotene intake (IRR: 0.85; 95% CI: 0.73-1.00) pr. 5000 μg of intake. We found a significant interaction between both dietary (p=0.005) and total (p=0.002) beta-carotene and smoking status, with a significant protective effect of beta-carotene seen among current smokers only.. Our results indicate no preventive effect of vitamin C, E, or folate on UC. We found a protective effect of dietary, but not supplemental, beta-carotene on UC, but further studies are required.

Topics: Ascorbic Acid; beta Carotene; Carcinoma, Transitional Cell; Denmark; Diet; Diet Records; Female; Folic Acid; Humans; Incidence; Male; Micronutrients; Middle Aged; Nutritional Status; Odds Ratio; Proportional Hazards Models; Prospective Studies; Risk Assessment; Risk Factors; Smoking; Time Factors; Urinary Bladder Neoplasms; Urothelium; Vitamin E

The association between several cancers and selenium status has been investigated in epidemiological studies. However, few results concerning bladder cancer have been reported thus far. The association between toenail selenium status and subsequent bladder cancer incidence was investigated in a prospective cohort study among 120,852 men and women aged 55-69 years at baseline (September 1986). The cohort members completed a questionnaire on risk factors for cancer and provided toenail clippings for determination of baseline selenium status. Follow-up for incident cancer was established by record linkage to cancer registries until December 1992. The multivariable case-cohort analysis was based on 431 bladder cancer cases and 2,459 subcohort members, for whom toenail selenium levels were available. The age-, sex- and smoking-adjusted rate ratios (95% confidence intervals) for increasing quintiles of toenail selenium were 1.00 (reference), 1.09 (0.80-1.48), 0.55 (0.38-0.79), 0.63 (0.43-0.91), and 0.67 (0.46-0.97), respectively (P-trend < 0.01). Analyses with selenium as a continuous variable supported these findings. An inverse association between toenail selenium and bladder cancer risk was most pronounced among ex-smokers (P-trend < 0.01); was similar for subjects with high versus low intakes of beta-carotene, vitamin C, and vitamin E; and was mainly confined to invasive transitional cell carcinomas of the urinary bladder, irrespective of tumor morphology. We conclude that the evidence is in favor of an inverse association between selenium and bladder cancer risk.

Topics: Aged; Antioxidants; Ascorbic Acid; beta Carotene; Carcinoma, Transitional Cell; Cohort Studies; Eating; Female; Follow-Up Studies; Humans; Incidence; Male; Middle Aged; Nails; Netherlands; Prospective Studies; Risk Factors; Selenium; Sex Factors; Smoking; Statistics as Topic; Urinary Bladder Neoplasms; Vitamin E

Topics: beta Carotene; Carcinoma in Situ; Carcinoma, Transitional Cell; Carotenoids; Humans; Kidney Neoplasms; Male; Middle Aged