cryptoxanthins and Head-and-Neck-Neoplasms

Experimental studies suggest that carotenoids and retinol may play a role in carcinogenesis, but epidemiological evidence is lacking. We investigated the prospective associations between plasma concentrations of major carotenoids and retinol, and overall and breast cancer risk. A nested case-control study included all first incident cancer cases diagnosed in the SU.VI.MAX cohort between 1994 and 2002 (n = 159 cases, 1 matched control/case). Baseline plasma concentrations of carotenoids and retinol were measured by high-performance liquid chromatography. Conditional logistic regression was used to assess odds ratios for an increase of 0.1 μmol/L [odds ratio (OR)] and 95% confidence intervals (CI). Plasma β-carotene (OR = 0.95, 95% CI = 0.90-0.99, Ptrend = 0.04) and β-cryptoxanthin concentrations (OR = 0.89, 95% CI = 0.81-0.99, Ptrend = 0.03) were inversely associated with overall cancer risk. Plasma β-cryptoxanthin concentration was inversely associated with breast cancer risk (OR = 0.83, 95% CI = 0.71-0.96, Ptrend = 0.02). The OR between plasma lycopene concentration and overall cancer risk was 1.07 (0.99-1.15), Ptrend = 0.06. This association turned significant (Ptrend = 0.01) when excluding cancer cases diagnosed during the first year of follow-up. This prospective study suggests an inverse association between plasma concentrations of β-cryptoxanthin and both overall and breast cancer risk, and an inverse association between β-carotene and overall cancer risk. The direct association between lycopene concentration and cancer risk deserves further investigation.

Topics: Adult; beta Carotene; Body Mass Index; Breast Neoplasms; Carotenoids; Case-Control Studies; Chromatography, High Pressure Liquid; Colorectal Neoplasms; Cryptoxanthins; Female; Follow-Up Studies; Head and Neck Neoplasms; Humans; Logistic Models; Lung Neoplasms; Lycopene; Male; Middle Aged; Prospective Studies; Prostatic Neoplasms; Randomized Controlled Trials as Topic; Risk Factors; Vitamin A

Smoking negatively affects serum carotenoid levels, and it is a negative prognostic factor for head and neck cancer. In this study, micronutrient levels were examined in 60 smoking and non-smoking head and neck cancer patients. The goal was to determine if oxidation of the carotenoid lycopene would occur to a greater extent in smokers. Subjects were drawn from a prospective cohort study and matched on seven demographic factors. Serum levels of alpha-carotene, zeaxanthin, and 2,6-cyclolycopene-1,5-diol A, an oxidation product of lycopene, were all lower in smokers versus non-smokers (18%, 22%, and 8%, respectively) while beta-carotene, beta-cryptoxanthin, and lutein were about the same in the two groups. Levels of lycopene, gamma-tocopherol, and alpha-tocopherol were higher in smokers, and notably serum alpha-tocopherol was 48% higher in smokers. The majority of vitamin E intake was from supplements. The higher levels of alpha-tocopherol in smokers were interesting in that higher alpha-tocopherol levels have been associated with higher mortality in head and neck cancer. Although this was a pilot investigation, there was no evidence that 2,6-cyclolycopene-1,5-diol A formation was appreciably affected by smoking status, but alpha-tocopherol levels were higher in smokers.

Topics: Adult; Aged; alpha-Tocopherol; beta Carotene; Carotenoids; Case-Control Studies; Cohort Studies; Cryptoxanthins; Diet Records; Female; gamma-Tocopherol; Head and Neck Neoplasms; Humans; Lutein; Lycopene; Male; Micronutrients; Middle Aged; Neoplasms, Squamous Cell; Oxidative Stress; Pilot Projects; Prospective Studies; Smoking; Xanthophylls; Zeaxanthins