Women with a certain gene mutation (BRCA 1/2) could be at greater risk of developing breast cancer if they undergo chest x-ray exams, and the risk is even greater if the exposure occurs before the age of 20, according to research conducted by a a consortium of European cancer centers. The research dubbed “International BRCA 1/2 Carrier Cohort Study (IBCCS)” was published in the Journal of Clinical Oncology.
The study evaluated 1,600 women at a genetically higher risk for breast cancer to better understand the impact of low-level x-ray exposure on the risk of developing the disease.
"This is one of the first studies to demonstrate that women genetically predisposed to breast cancer may be more susceptible to low-dose ionizing radiation than other women," said David E. Goldgar, PhD, one of the study’s lead authors, and chief of the Genetic Epidemiology Group at the International Agency for Research on Cancer in Lyon, France, at the time the research was conducted. "If confirmed in prospective studies, young women who are members of families known to have BRCA1 or BRCA2 mutations may wish to consider alternatives to x-ray, such as MRI," Goldgar added.
While all women were in the study were carriers of the gene mutation, not all had developed breast cancer. The study questionnaire asked whether participants received a chest x-ray, and also focused on the age at which the exam occurred -- before age 20, after age 20, or during both periods – and the amount of exams.
According to the responses, the study found that women who reported having a chest x-ray were 54 percent more likely to develop breast cancer than women who had never undergone the procedure. In comparison with women who had never been exposed, women who were before age 20 had a 2.5-fold increased risk of developing the disease before age 40.
"Since BRCA proteins are integral in repairing damage to breast cells, we hypothesized that women with BRCA 1/2 mutations would be less able to repair damage caused to DNA by ionizing radiation," said Goldgar. "Our findings support this hypothesis and stress the need for prospective studies."