Article

Is low selenium status a risk factor for lung cancer?

National Public Health Institute, Helsinki, Finland.
American Journal of Epidemiology (Impact Factor: 4.98). 12/1998; 148(10):975-82. DOI: 10.1093/oxfordjournals.aje.a009574
Source: PubMed

ABSTRACT The hypothesis that low selenium may in some circumstances be a risk factor for lung cancer was investigated in a case-control study nested within a longitudinal study. Serum samples from 9,101 cancer-free individuals were collected and stored at -20 degrees C by the Finnish Mobile Clinic in 1968-1971 and 1973-1976. During follow-up until the end of 1991, 95 cases of lung cancer were diagnosed. Selenium concentrations were determined from the serum samples of the cases and 190 controls, individually matched for sex, age, and place of residence. Mean levels of serum selenium in cases and controls were 53.2 microg/liter and 57.8 microg/liter, respectively. The relative risk of lung cancer between the highest and lowest tertiles of serum selenium, adjusted for smoking, serum alpha-tocopherol, serum cholesterol, serum copper, serum orosomucoid, and body mass index (kg/m2), was 0.41 (95% confidence interval (CI) 0.17-0.94). The association was stronger at lower levels (<5.9 mg/liter) of alpha-tocopherol (relative risk=0.24, 95% CI 0.07-0.85). The association was also pronounced among current smokers and at higher levels of serum orosomucoid and serum copper. The relative risk for smokers who were twice ranked in higher selenium tertiles, at an interval of 4-7 years, in comparison with smokers who remained in the lowest tertile was 0.16 (95% CI 0.04-0.74). In accordance with the hypothesis, the findings suggest that very low selenium status may contribute to the risk of lung cancer.

0 Followers
 · 
51 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE:Selenium is a fundamental nutrient to human health that might have anticarcinogenic effects. Previous studies have assessed the possible relationship of selenium status to colorectal adenomas with controversial results. We primarily aimed to assess the relationship of serum selenium status with the presence of large size colorectal adenomas in subjects living in a poor selenium region. The serum selenium status in colorectal cancer was also evaluated.METHODS:Serum selenium levels were measured in 28 patients with large size sporadic adenomatous polyps, 24 patients with colorectal adenocarcinomas, and 35 age-matched healthy individuals. A logistic regression analysis was performed to assess the relationship of serum selenium to colorectal adenomatous polyps after adjusting for confounding variables (age, sex, smoking habit, and alcohol drinking).RESULTS:Among subjects aged ≤60 yr, mean serum selenium levels were significantly lower in both patient groups (adenoma, 57.9 ± 4.3 μg/L; cancer, 43.7 ± 6.6 μg/L) than in healthy controls (88.9 ± 8 μg/L) (p = 0.0001). There were no difference among subjects >60 yr old. A significant inverse association between selenium status and the diagnosis of large size adenomatous polyps after adjusting for confounding variables was found (adjusted p = 0.029). Subjects with higher selenium status (≥75th percentile value of 82.11 μg/L) had a lower probability (OR = 0.17, 95% CI = 0.03–0.84) to be in the adenoma group than subjects with lower selenium status (<82.11 μg/L). This association was more marked in subjects aged ≤60 yr (adjusted p value = 0.04, OR = 0.08, 95% CI = 0.007–0.91), and was not significant in older subjects.CONCLUSIONS:Results suggest that high selenium status may decrease the risk of large size adenomas in a low selenium region, and that this preventive effect seems to be exclusive to subjects ≤60 yr. These results will need to be confirmed in additional epidemiological studies before recommending selenium supplementation in patients with colon adenomas.
    The American Journal of Gastroenterology 01/2002; 97(8):2103-2108. DOI:10.1016/S0002-9270(02)04287-9 · 9.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Selenium has been shown to prevent cancer in animal models, and recent data indicate it is likely to be effective in humans as well. One selenium-containing protein, the cytoplasmic form of glutathione peroxidase (GPx-1), has been implicated in cancer risk and development by genetic studies identifying at-risk alleles and loss of heterozygosity in tumors. In order to evaluate the biological consequences of GPx-1 overexpression, human MCF-7 cells were stably transfected with a GPx-1 expression construct and the effects of GPx-1 on protein kinases associated with stress responses were determined. GPx-1 overexpression affected phosphorylation of p70S6K, whereas Erk1/2 and p38 MAPK were not affected. Site-specific phosphorylation of Akt declined and the levels of Gadd45, a DNA damage response protein, increased significantly as a consequence of elevated GPx-1 expression. Effects on p70S6K and Gadd45 after selenium supplementation have been reported, and given previous data demonstrating a role for GPx-1 in cancer etiology, these results support the concept that the chemopreventive properties of selenium may be due, at least in part, to its role in regulating GPx-1.
    Free Radical Biology and Medicine 05/2004; DOI:10.1016/S0891-5849(04)00384-3 · 5.71 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Individuals exposed to fibrogenic mineral dust may exhibit an impaired antioxidant system and produce high levels of reactive oxygen and nitrogen species through immune cells, contributing to the perturbation of immune cell function, inflammation, fibrosis and lung cancer. The lung diseases which are caused by inhalation of fibrogenic mineral dust, known as pneumoconioses, develop progressively and irreversibly over decades. At the moment there is no known cure. The trace element selenium has potent antioxidant and anti-inflammatory properties mediated mainly through selenoproteins. Research has demonstrated that selenium has the ability to protect against cardiovascular diseases; to kill cancer cells in vitro and reduce cancer incidence; and to immunomodulate various cellular signaling pathways. For these reasons, selenium has been proposed as a promising therapeutic agent in oxidative stress associated pathology that in theory would be beneficial for the prevention or treatment of pneumoconioses such as silicosis, asbestosis, and coal worker's pneumoconiosis. However, studies regarding selenium and occupational lung diseases are rare. The purpose of this study is to conduct a mini-review regarding the relationship between selenium and exposure to fibrogenic mineral dust with emphasis on epidemiological studies. We carried out a systematic literature search of English published studies on selenium and exposure to fibrogenic mineral dust. We found four epidemiological studies. Reviewed studies show that selenium is lower in individuals exposed to fibrogenic mineral dust. However, three out of the four reviewed studies could not confirm cause-and-effect relationships between low selenium status and exposure to fibrogenic mineral dust. This mini-review underscores the need for large follow-up and mechanistic studies for selenium to further elucidate its therapeutic effects. Copyright © 2015 Elsevier Ltd. All rights reserved.

Full-text (2 Sources)

Download
14 Downloads
Available from
Jun 1, 2014