Protective effects of plasma carotenoids on the risk of bladder cancer.
OBJECTIVE
We examined the associations between plasma micronutrients and bladder cancer risk, and evaluated the combined effects of carotenoid and cigarette smoke.


METHODS
We performed a case-control study in 242 patients with bladder cancer and 204 healthy controls at Memorial Sloan-Kettering Cancer Center from 1993 to 1997. Epidemiological data and blood specimens were collected on 84 cases and 173 controls. Plasma micronutrients, including lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, beta-carotene, retinol, alpha-tocopherol and gamma-tocopherol, were determined by high performance liquid chromatography. The logistic regression model was used to estimate the effects from carotenoid, tocopherol and retinol on the risk of bladder cancer.


RESULTS
Based on quartiles of plasma micronutrient levels and continuous variables, adjusted ORs were estimated for bladder cancer after controlling for potential confounders, including patient age, sex, education and pack-years of smoking. When using plasma levels of micronutrients as continuous variables, the adjusted OR was 0.22 (95% CI 0.05 to 0.92) for alpha-carotene, 0.42 (95% CI 0.18 to 1.00) for lutein, 0.16 (95% CI 0.02 to 1.06) for zeaxanthin, 0.94 (95% CI 0.89 to 0.99) for lycopene and 0.90 (95% CI 0.81 to 1.00) for beta-cryptoxanthin. The adjusted OR for the joint effect of plasma carotenoids and tobacco smoking was 6.22 (95% CI 1.87 to 20.8) in smokers with lower lutein and 5.18 (95% CI 1.57 to 17.1) in smokers with lower zeaxanthin.


CONCLUSIONS
Our results show protective effects of carotenoids on bladder cancer. They suggest that bladder cancer may be a preventable disease through nutritional intervention, especially in smokers.
Hung
Rayjean J
RJ
Department of Epidemiology, University of California-Los Angeles, Los Angeles, CA, USA.
Zhang
Zuo-Feng
ZF
Rao
Jian Yu
JY
Pantuck
Allan
A
Reuter
Victor E
VE
Heber
David
D
Lu
Qing-Yi
QY
D002338:Carotenoids / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D024505:Tocopherols / Q000097:blood*; D001749:Urinary Bladder Neoplasms / Q000097:blood* / Q000209:etiology* / Q000517:prevention & control; D014801:Vitamin A / Q000097:blood*
D014801:Vitamin A; D002338:Carotenoids; D024505:Tocopherols