Endometrial cancer incidence in relation to electric blanket use

Magnetic Fields and Cancer: Epidemiology, Cellular Biology, and Theranostics

Humans are exposed to a complex mix of man-made electric and magnetic fields (MFs) at many different frequencies, at home and at work. Epidemiological studies indicate that there is a positive relationship between residential/domestic and occupational exposure to extremely low frequency electromagnetic fields and some types of cancer, although some other studies indicate no relationship. In this review, after an introduction on the MF definition and a description of natural/anthropogenic sources, the epidemiology of residential/domestic and occupational exposure to MFs and cancer is reviewed, with reference to leukemia, brain, and breast cancer. The in vivo and in vitro effects of MFs on cancer are reviewed considering both human and animal cells, with particular reference to the involvement of reactive oxygen species (ROS). MF application on cancer diagnostic and therapy (theranostic) are also reviewed by describing the use of different magnetic resonance imaging (MRI) applications for the detection of several cancers. Finally, the use of magnetic nanoparticles is described in terms of treatment of cancer by nanomedical applications for the precise delivery of anticancer drugs, nanosurgery by magnetomechanic methods, and selective killing of cancer cells by magnetic hyperthermia. The supplementary tables provide quantitative data and methodologies in epidemiological and cell biology studies. Although scientists do not generally agree that there is a cause-effect relationship between exposure to MF and cancer, MFs might not be the direct cause of cancer but may contribute to produce ROS and generate oxidative stress, which could trigger or enhance the expression of oncogenes.

Campos magnéticos de frequência extremamente baixa e efeitos na saúde: revisão da literatura

A partir da publicação, em 1979, dos resultados de um estudo que apontava para o aumento do risco de leucemia em crianças associado à exposição a campos magnéticos, o interesse pelo tema vem aumentando, e diversos estudos foram publicados. O objetivo desta revisão é apresentar os diferentes métodos utilizados na avaliação da exposição aos campos magnéticos de frequência extremamente baixa, bem como as dificuldades enfrentadas na quantificação dessa exposição, além de relatar os resultados de estudos epidemiológicos publicados nos últimos 10 anos. A falta de um modelo fisiopatológico que explique uma possível influência dos campos magnéticos na saúde e a dificuldade para quantificar a exposição têm sido os maiores obstáculos da pesquisa na área. Leucemia e tumores do sistema nervoso central têm sido os efeitos mais estudados. Leucemia em crianças é o desfecho mais consistentemente associado à exposição a campos magnéticos. Estudos mais recentes apontam a associação entre esclerose lateral amiotrófica e campos magnéticos.

Use of electric blankets and association with prevalence of endometrial cancer

The objective of this study was to assess the relationship between electric blanket use and prevalence of endometrial cancer for women. Information relating to women enrolled in the Women's Health Initiative Observational Data Set (n=93 676) used to test the relationship factors associated with endometrial cancer included older age at screening, younger age at last menstrual period, region of domicile (highest prevalence in the South), less than a high school education, lower income, body mass index >25 kg/m, low parity, unopposed use of estrogen, never use of estrogen plus progesterone, past alcohol use, higher percentage of daily calories from fat and any electric blanket use. Following a univariate identification of factors significantly related to endometrial cancer, stepwise logistic regression analysis was performed for those factors with P values of less than 0.001 in the univariate analysis. Using electric blankets was associated with a 15% higher prevalence of endometrial cancer than never having used electric blankets (odds ratio=1.15, 95% confidence interval: 1.03-1.27). After controlling for variables significantly associated with endometrial cancer, use of electric blankets for 20 years or more was associated with 36% higher prevalence of endometrial cancer (odds ratio=1.36, 95% confidence interval: 1.16-1.59). Although we were unable to determine the duration of electric blanket use before diagnosis of endometrial cancer, we found that women using electric blankets for 20 years or more had a significantly higher prevalence.