Breast cancer

Int J Epidemiol. 1982 Dec;11(4):345-55.

Adult cancer related to electrical wires near the home.
Wertheimer N, Leeper E.

Like childhood cancer, adult cancer was found to be associated with high-current electrical wiring configurations (HCCs) near the patient's residence. Such wiring can expose occupants of the residence to alternating magnetic fields (AMFs) at a level which, though very low, may produce physiological effects. Several patterns in the data suggest that HCCs and cancer may be causally linked: (1) a dose-relationship was found. (2) The association did not appear to be an artefact of age, urbanicity, neighbourhood, or socioeconomic level. (3) The association was most clearly demonstrable where cancer caused by urban/industrial factors was least apt to obscure the effect. (4) A distinct pattern of latency between first exposure to the HCC and cancer diagnosis was seen, which is consistent with a hypothesis of cancer promotion produced by AMF exposure.

Br J Cancer. 1986 Feb;53(2):271-9.

Mortality of persons resident in the vicinity of electricity transmission facilities.
McDowall ME.

Several studies have raised the possibility that exposure to electrical and/or magnetic fields may be injurious to health in particular by the promotion or initiation of cancer. To investigate whether the electricity transmission system presents a long term hazard to public health, the mortality of nearly 8,000 persons, identified as living in the vicinity of electrical transmission facilities at the time of the 1971 Population Census, has been followed to the end of 1983. All identified transmission installations within pre-defined areas were included in the study with the result that the greater part of the study group were believed to be resident near relatively low voltage sub-stations. Overall mortality was lower than expected and no evidence of major health hazards emerged. The only statistically significant excess mortality was for lung cancer (in women overall, and in persons living closest to the installations); this result is difficult to interpret in the absence of smoking data, and is not supported by other evidence but does not appear to be due to the social class distribution of the study group. The study did not support previously reported associations of exposure to electro-magnetic fields with acute myeloid leukaemia, other lymphatic cancers and suicide.

Int J Epidemiol. 1993 Feb;22(1):9-15.

Cancer mortality and residence near electricity transmission equipment: a retrospective cohort study.
Schreiber GH, Swaen GM, Meijers JM, Slangen JJ, Sturmans F.

Department of Epidemiology, University of Limburg, Maastricht, The Netherlands.

Several studies in recent years have raised the possibility that exposure to extreme low frequency (ELF) electromagnetic fields may be hazardous to human health, in particular by the promotion or initiation of leukaemia and other cancers. To determine if this exposure creates a long-term hazard to the public, the mortality of a group of people identified as having lived in an urban quarter of Maastricht in which two 150 kiloVolt (kV) powerlines and one transformer substation are located was investigated. Using the Dutch population registry it was possible to identify retrospectively 3549 inhabitants of the quarter who lived there for at least 5 years between 1956 and 1981. Of these 1552 study subjects lived within 100 m of the electricity transmission equipment and were exposed to magnetic field intensity of 1.0-11.0 milliGauss. The overall standardized mortality ratio and cancer mortality ratios were either not or only slightly elevated. The study does not support previously reported associations of exposure to ELF electromagnetic fields with leukaemia, brain cancer and breast cancer.

Am J Epidemiol. 2002 Mar 1;155(5):446-54.

Residential magnetic fields and the risk of breast cancer.
Davis S, Mirick DK, Stevens RG.

Program In Epidemiology, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North MP-474, Seattle, WA 98109-1024, USA.

Chronic exposure to 60-Hz magnetic fields may increase the risk of breast cancer by suppressing the normal nocturnal production of melatonin. This population-based case-control study investigated whether such exposure is associated with an increased risk of breast cancer in women aged 20-74 years from the greater Seattle, Washington, area. Cases were diagnosed between November 1992 and March 1995 (n = 813); controls were identified by random digit dialing and were frequency matched by 5-year age groups (n = 793). Exposure was estimated using magnetic field measurements in the home at diagnosis, wiring configuration of all homes occupied in the 10 years prior to diagnosis, and self-reported measures of at-home electric appliance use. Odds ratios and 95% confidence intervals were estimated using conditional logistic regression with adjustment for other potential risk factors. Risk did not increase with measured nighttime bedroom magnetic field level, wiring configuration of the home at diagnosis, weighted summary wire codes of all homes occupied 5 and 10 years prior to diagnosis, or reported use of common household appliances, including bed-warming devices. These data do not support the hypothesis that exposure to residential magnetic fields is associated with an increased risk of developing breast cancer.

Am J Epidemiol. 2003 Nov 15;158(10):969-80.

Residential magnetic field exposure and breast cancer risk: a nested case-control study from a multiethnic cohort in Los Angeles County, California.
London SJ, Pogoda JM, Hwang KL, Langholz B, Monroe KR, Kolonel LN, Kaune WT, Peters JM, Henderson BE.

Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.

Some experimental and epidemiologic evidence suggests that residential exposure to power-frequency magnetic fields can increase breast cancer risk. This association was investigated in a nested case-control study of female breast cancer within a cohort of African Americans, Latinas, and Caucasians in Los Angeles County, California. Incident breast cancer was ascertained from 1993 to 1999 by linkage to county and state tumor registries. Controls were selected from a random sample of cohort members without breast cancer at baseline. Exposure was assessed in 1995-2001 by means of wiring configuration coding (an indirect measure of magnetic field exposure that has been associated with increased risk of childhood leukemia in Los Angeles and elsewhere in North America) in all homes occupied over the previous 10 years for 743 cases and 699 controls and by measurement of magnetic fields in the bedroom over a 7-day period for 347 cases and 286 controls. The estimated risk of breast cancer was not higher among women with wiring configuration codes associated with the highest magnetic fields (for a very high current configuration relative to very low, the adjusted odds ratio was 0.76 (95% confidence interval: 0.49, 1.18)). Stronger measured fields were not significantly associated with increased risk. These data suggest that residential magnetic field exposures commonly experienced by US women do not influence risk of breast cancer.

Am J Epidemiol. 2003 Jul 1;158(1):47-58.

Electromagnetic fields and breast cancer on Long Island: a case-control study.
Schoenfeld ER, O'Leary ES, Henderson K, Grimson R, Kabat GC, Ahnn S, Kaune WT, Gammon MD, Leske MC; EBCLIS Group.

Department of Preventive Medicine, School of Medicine, Stony Brook University, Stony Brook, NY 11794-8036, USA.

The EMF and Breast Cancer on Long Island Study (EBCLIS) was a case-control study designed to evaluate the possible association between exposure to electromagnetic fields (EMFs) and breast cancer. Eligible women were participants in the population-based Long Island Breast Cancer Study Project, were under 75 years of age at enrollment, were residentially stable, and were identified between August 1, 1996, and June 20, 1997. Of those eligible, 576 cases and 585 controls participated in EBCLIS (87% and 83%, respectively). In-home data collection included various spot and 24-hour EMF measurements, ground-current magnetic field measurements, wire mapping of overhead power lines servicing the home, and an interview. Odds ratios and 95% confidence intervals were based on multivariate logistic regression analyses. All odds ratios were close to 1 and nonsignificant. For the highest quartile of 24-hour EMF measurements, the odds ratio was 0.97 (95% confidence interval (CI): 0.69, 1.37) in the bedroom and 1.09 (95% CI: 0.78, 1.51) in the most lived-in room. For the highest exposure category of ground-current measurements, the odds ratio was 1.13 (95% CI: 0.88, 1.44) in the bedroom and 1.08 (95% CI: 0.85, 1.38) in the most lived-in room. These and other EBCLIS results agree with other recent reports of no association between breast cancer and residential EMF exposures.

Am J Epidemiol. 2004 May 1;159(9):852-61.

Residential and occupational exposures to 50-Hz magnetic fields and breast cancer in women: a population-based study.
Kliukiene J, Tynes T, Andersen A.

The Cancer Registry of Norway, Institute of Population-based Cancer Research, Oslo, Norway.

A case-control study was conducted to investigate whether residential and occupational exposures to magnetic fields increased the risk for breast cancer among women. Cases of breast cancer diagnosed during 1980-1996 were identified in a cohort of women living near a high-voltage power line in Norway in 1980 or between 1986 and 1996. Each case was matched by year of birth, municipality, and first year of entry into the cohort with two randomly selected controls without cancer. Residential exposure to magnetic fields was calculated as that generated by the lines before diagnosis, and occupational exposure was based on exposure matrix data. Women with residential exposure had an odds ratio of 1.58 (95% confidence interval (CI): 1.30, 1.92) when compared with unexposed women. The odds ratios for exposed women versus unexposed women with estrogen receptor (ER)-positive and ER-negative breast cancer were 1.33 (95% CI: 0.93, 1.90) and 1.40 (95% CI: 0.78, 2.50), respectively (ER status was available for 44% of the cases). Women with the highest occupational exposure had an odds ratio of 1.13 (95% CI: 0.91, 1.40) when compared with those unexposed at work. The findings suggest an association between exposure to magnetic fields and breast cancer in women.