According to a combined analysis of previous studies, low-dose radiation from annual mammograms may increase the risk of breast cancer among women with genetic or familial predisposition to the disease. These results were presented at the annual meeting of the Radiological Society of North America.
Mammograms (X-ray images of the breasts) are commonly used to screen women for breast cancer. The age at which screening should begin varies by a woman’s risk of breast cancer; women at high risk of breast cancer are usually advised to begin screening at a younger age than average-risk women.
Because mammograms involve exposure to low doses of radiation, it’s possible that repeated exposures over many years could lead to some cases of radiation-induced breast cancer.
To explore the risk of breast cancer among women who were and were not exposed to low-dose radiation, researchers in the Netherlands evaluated information from six previous studies. All of the studies focused on women who were considered to be at high risk of breast cancer as a result of genetic predisposition or family history.
- Overall, risk of breast cancer was 1.5 times greater among women who had been exposed to low-dose radiation than among women who had not been exposed.
- A 2.5-fold increase in risk was observed among women who had been exposed to low-dose radiation before the age of 20 or who had five or more exposures.
In a prepared statement, the lead researcher noted: “For women at high risk for breast cancer, screening is very important, but a careful approach should be taken when considering mammography for screening young women, particularly under age 30. Further, repeated exposure to low-dose radiation should be avoided.”
The researcher stated that these results should be interpreted with caution. It’s also important to keep in mind that these results may apply only to certain groups of high-risk women (average-risk women were not evaluated).
Women who have questions about how and when they should be screened for breast cancer are advised to talk with their healthcare provider.
Reference: Jansen-van der Weide MC, de Bock GH, Greuter MJW et al. Mammography screening and radiation-induced breast cancer among women with a familial or genetic predisposition: a metaanalysis. Presented at the 2009 annual meeting of the Radiological Society of North America. November 29-December 4, 2009, Chicago, IL. Abstract R022-04.