Researchers have found that low dose radiation from annual mammography screening for women with genetic or familial predisposition to breast cancer may increase the risk.
The research suggested that women, who are at high risk for breast cancer, need to begin screening at a younger age, because they often develop cancer earlier than women at average risk.
"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," said Dr. Marijke C. Jansen-van der Weide, epidemiologist in the Department of Epidemiology and Radiology at University Medical Center Groningen in the Netherlands.
However, Jansen-van der Weide and colleagues said that young women with familial or genetic predisposition to the disease might want to consider alternative screening methods to mammography, because the benefit of early tumour detection in this group of women may be offset by the potential risk of radiation-induced cancer.
There are conflicting reports regarding the benefits of mammography for women under 40. Alternative screening methods such as ultrasound and MRI may be made available to younger women, but are generally used as an adjunct to mammography.
The researchers conducted an analysis of peer-reviewed published medical research, to determine if low-dose radiation exposure affects breast cancer risk among high-risk women.
Out of 47 articles found on the topic, six were selected by the reviewers for inclusion in their analysis.
Four studies looked at the effect of exposure to low-dose radiation among breast cancer gene mutation carriers, and two studies researched the effect of radiation on women with a family history of breast cancer.
Using data from these studies, the researchers were able to calculate pooled odds ratios to estimate radiation-induced breast cancer risk.
The results showed that among all high-risk women in the study, average increased risk of breast cancer due to low-dose radiation exposure was 1.5 times greater than that of high-risk women not exposed to low-dose radiation.
High-risk women exposed before age 20 or with five or more exposures, were 2.5 times more likely to develop breast cancer than high-risk women not exposed to low-dose radiation.
"Our findings suggest that low-dose radiation increases breast cancer risk among these young high-risk women and a careful approach is warranted," said Jansen-van der Weide.
The study was presented at the annual meeting of the Radiological Society of North America (RSNA).