Is mammography indicated for women with defective BRCA genes? Implications of recent scientific advances for the diagnosis, treatment, and prevention of hereditary breast cancer.

Abstract

About 5% of breast cancer patients have inherited their disease because of a mutation in genes encoding either the BRCA-1 or BRCA-2 proteins. Inheriting one of these mutations confers a 50% to 87% risk of breast cancer. Many physicians faced with such a patient would, at a minimum, suggest increased and earlier screening for breast cancer by routine mammography.[1] Normally, regular mammographic screening combined with appropriate and prompt treatment can reduce mortality from breast cancer by 30% in women aged 50-59 years and by about 14%-18% in women aged 40-49. There are no controlled clinical trials for screening young women who have multiple first-degree relatives developing breast cancer before age 45, or those known to carry BRCA-1 or BRCA-2 mutations. In fact, recent advances point out that BRCA-1 and BRCA-2 gene products are needed to repair radiation damage to DNA.[4,5] Based on this finding, I propose that women with defective BRCA genes are likely to have an inordinate sensitivity to radiation, and this raises a question about the advisability of routinely screening these women by frequent mammography.