beta-carotene and Endometrial-Neoplasms

Antioxidant vitamins may reduce cancer risk by limiting oxidative DNA damage. To summarize and quantify the current epidemiologic evidence of an association between antioxidant vitamin intake and endometrial cancer, we conducted a systematic literature review and meta-analysis. One cohort and 12 case-control studies presenting relevant risk estimates were identified by conducting bibliographical searches through June 2008. Dose-response meta-analyses were conducted for beta-carotene, vitamin C, and vitamin E from food sources. Intake from supplements was not considered in the meta-analyses because of the few studies that reported relevant information. Based on case-control data, the random-effects summary odds ratios (OR) were, for beta-carotene: 0.88 (95% CI: 0.79-0.98) per 1,000 mcg/1,000 kcal (I2: 77.7%; p < 0.01); for vitamin C: 0.85 (95% CI: 0.73-0.98) per 50 mg/1,000 kcal (I2: 66.1%; p < 0.01); and, for vitamin E: 0.91 (95% CI: 0.84-0.99) per 5 mg/1,000 kcal (I2: 0.0%; p: 0.45). In contrast, the only prospective study identified provided little indication of an association. Although the current case-control data suggest an inverse relationship of endometrial cancer risk with dietary intakes of beta-carotene, vitamin C, and vitamin E from food sources, additional studies are needed, particularly cohort studies, to confirm an association.

Topics: Adult; Antioxidants; Ascorbic Acid; beta Carotene; Case-Control Studies; Dose-Response Relationship, Drug; Endometrial Neoplasms; Female; Humans; Male; Middle Aged; Prospective Studies; Risk Factors; Vitamin E; Vitamins

To examine the relation between the plasma concentration of antioxidant micronutrients and endometrial cancer risk in Korean women.. Hospital-based case-control study.. Seven tertiary medical institutes in Korea.. Incidence of 28 endometrial cancer cases were identified and 140 age-matched controls selected for the same period.. Preoperative plasma concentrations of beta-carotene, lycopene, zeaxanthin plus lutein, retinol, alpha-tocopherol, and gamma-tocopherol were measured by reverse-phase, gradient high-pressure liquid chromatography. Conditional logistic regression was used to evaluate micronutrient effect after adjustment for body mass index (BMI), menopause, parity, oral contraceptive use, smoking status, and alcohol consumption status.. Effect of micronutrients on endometrial cancer risk.. The mean concentration of plasma beta-carotene (p=0.001), lycopene (p=0.008), zeaxanthin plus lutein (p=0.031), retinol (p=0.048), and gamma-tocopherol (p=0.046) were significantly lower in endometrial cancer patients than in controls. Plasma levels of beta-carotene (p for trend=0.0007) and lycopene (p for trend=0.007) were inversely associated with endometrial cancer risk across tertiles. Women in the highest tertile of plasma beta-carotene and lycopene had a 0.12-fold (95% confidence intervals (CIs) 0.03-0.48) and 0.15-fold (95% CIs 0.04-0.61) decreased risk of endometrial cancer compared to women in the lowest tertile, respectively. Other micronutrients such as zeaxanthin plus lutein (p for trend=0.142), retinol (p for trend=0.108), alpha-tocopherol (p for trend=0.322), and gamma-tocopherol (p for trend=0.087) showed no association with endometrial cancer risk.. Plasma levels of beta-carotene and lycopene are inversely associated with the risk of endometrial cancer in Korean women.

Topics: Analysis of Variance; Anticarcinogenic Agents; Antioxidants; beta Carotene; Body Mass Index; Carotenoids; Case-Control Studies; Chromatography, High Pressure Liquid; Contraceptives, Oral; Dietary Supplements; Educational Status; Endometrial Neoplasms; Female; Humans; Logistic Models; Lycopene; Micronutrients; Middle Aged; Risk Factors; Smoking

The antiproliferative properties of lycopene, the major tomato carotenoid, were compared with those of alpha- and beta-carotene. Lycopene, delivered in cell culture medium from stock solutions in tetrahydrofuran, strongly inhibited proliferation of endometrial (Ishikawa), mammary (MCF-7), and lung (NCI-H226) human cancer cells with half-maximal inhibitory concentration of 1-2 microM; alpha- and beta-carotene were far less effective inhibitors. For example, in Ishikawa cells, a 4-fold higher concentration of alpha-carotene or a 10-fold higher concentration of beta-carotene was needed for the same order of growth suppression. The inhibitory effect of lycopene was detected after 24 hours of incubation, and it was maintained for at least three days. In contrast to cancer cells, human fibroblasts were less sensitive to lycopene, and the cells gradually escaped growth inhibition over time. In addition to its inhibitory effect on basal endometrial cancer cell proliferation, lycopene also suppressed insulin-like growth factor-I-stimulated growth. Insulin-like growth factors are major autocrine/paracrine regulators of mammary and endometrial cancer cell growth. Therefore, lycopene interference in this major autocrine/paracrine system may open new avenues for research on the role of lycopene in the regulation of endometrial cancer and other tumors.

Topics: Anticarcinogenic Agents; beta Carotene; Breast Neoplasms; Carotenoids; Cell Division; DNA; Dose-Response Relationship, Drug; Endometrial Neoplasms; Female; Humans; Insulin-Like Growth Factor I; Lung Neoplasms; Lycopene; Tumor Cells, Cultured