Epidemiological study (observational study)

Extremely low-frequency electromagnetic fields exposure and female breast cancer risk: a meta-analysis based on 24,338 cases and 60,628 controls. epidem.

By: Chen C, Ma X, Zhong M, Yu Z

Published in: Breast Cancer Res Treat 2010; 123 (2): 569-576

Aim of study (acc. to author)

A meta-analysis was performed to evaluate the risk of female breast cancer associated with extremely low-frequency electromagnetic fields exposure.

Further details

15 case-control studies which were published in 13 publications over the period 2000 to 2009 were included in the meta-analysis: Zheng et al 2000, McElroy et al 2001, Wjingaarden et al 2001, Davis et al 2002, Kabat et al 2003 (including two different series of cases and controls), Schoenfeld et al 2003, Kliukiene et al 2003, Labreche et al 2003, London et al 2003 (including two different series of cases and controls), Zhu et al 2003, Kliukiene et al 2004, Forssen et al 2005, and McElroy et al 2007.
Different types of exposure assessment were used in the studies. The data of each study was categorized in the two categories magnetic field exposure less than 0.2 µT or more than 0.2 µT.

Endpoint/type of risk estimation

breast cancer

Type of risk estimation:

incidence

(odds ratio (OR))

Exposure

- electric blanket
- occupational
- residential

Exposure groups

Group	Description
Reference group 1	magnetic field exposure: < 0.2 µT
Group 2	magnetic field exposure: ≥ 0.2 µT

Population

Group:
- women
Age: 15–75 years
Characteristics: breast cancer
Observation period: 1976 - 2001
Study location: USA, Canada, Norway, and Sweden

Study size

Type	Value
Total	24,338

Statistical analysis method:

unconditional logistic regression
heterogeneity test, Funnel plot

Conclusion (acc. to author)

The results showed no statistical significant association between extremely low-frequency electromagnetic fields exposure and female breast cancer risk in total analysis (OR 0.988, CI 0.898-1.088). Also no statistical significant association was observed in all the subgroup analyses by exposure modes (residential, occupational, electric blanket use), menopausal status, and estrogen receptor status.
In conclusion, the meta-analysis suggests that extremely low-frequency electromagnetic fields exposure is not associated with the risk of female breast cancer.

Study funded by

National Natural Science Foundation (NSFC), China

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