Abstract
Background: The effects of low-dose medical radiation on breast cancer risk are uncertain, and few studies have included genetically susceptible women, such as those who carry germline BRCA1 and BRCA2 mutations. Methods: We studied 454 BRCA1 and 273 BRCA2 mutation carriers ages younger than 50 years from three breast cancer family registries in the United States, Canada, and Australia/New Zealand. We estimated breast cancer risk associated with diagnostic chest X-rays by comparing mutation carriers with breast cancer (cases) with those without breast cancer (controls). Exposure to chest X-rays was self-reported. Mammograms were not considered in the analysis. Results: After adjusting for known risk factors for breast cancer, the ORs for a history of diagnostic chest Xrays, excluding those for tuberculosis or pneumonia, were 1.16 [95% confidence interval (CI), 0.64-2.11] for BRCA1 mutations carriers and 1.22 (95% CI, 0.62-2.42) for BRCA2 mutations carriers. The OR was statistically elevated for BRCA2 mutation carriers with three to five diagnostic chest X-rays (P=0.01) but not for those with six or more chest X-rays. Few women reported chest fluoroscopy for tuberculosis or chest X-rays for pneumonia; the OR estimates were elevated, but not statistically significant, for BRCA1 mutation carriers. Conclusions: Our findings do not support a positive association between diagnostic chest X-rays and breast cancer risk before the ages of 50 years for BRCA1 or BRCA2 mutation carriers. Impact: Given the increasing use of diagnostic imaging involving higher ionizing radiation doses, further studies of genetically predisposed women are warranted.
Original language | English |
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Pages (from-to) | 1547-1556 |
Number of pages | 10 |
Journal | Cancer Epidemiology Biomarkers and Prevention |
Volume | 22 |
Issue number | 9 |
DOIs | |
State | Published - Sep 2013 |
Keywords
- Adult
- Australia/epidemiology
- Breast Neoplasms/diagnostic imaging
- Canada/epidemiology
- Diagnostic Tests, Routine
- Female
- Genes, BRCA1
- Genes, BRCA2
- Genetic Predisposition to Disease
- Humans
- Middle Aged
- Mutation
- New Zealand/epidemiology
- Radiography, Thoracic/statistics & numerical data
- Risk Assessment
- Risk Factors
- United States/epidemiology