Breast cancer mortality reduction outweighs radiation-induced risk inBRCAcarriers
02 feb 2009 -- For women carrying mutations in the BRCA gene, who are advised to begin mammography screening at as early as 25 to 30 years of age, the reduction in breast cancer mortality outweighs the risk of radiation-induced cancer mortality in women screened annually at 35 to 39 years of age but maybe not younger age groups, according to the results of a study published in the Feb. 4 issue of the Journal of the National Cancer Institute.
Amy Berrington de Gonzalez, from the Johns Hopkins Bloomberg School of Public Health in Baltimore, and colleagues developed a model to estimate the lifetime risk of radiation-induced breast cancer from mammography screening in young women (under 40 years old) carrying BRCA mutations, then estimated reduction in breast cancer mortality due to mammography compared with radiation risk.
The researchers found that the lifetime risk of radiation-induced breast cancer mortality due to annual mammography fell with increasing age at screening, from 26 per 10,000 women screened from 25 to 29 years old to 13 per 10,000 women screened from 35 to 39 years old. The reduction in breast cancer mortality needed to outweigh this risk also decreased with increasing age at screening, from 51 percent at 25 to 29 years of age to 4 percent at 35 to 39 years of age.
"If we assume that the mortality reduction from mammography is 15 percent to 25 percent or less for young women, these results suggest that there would be no net benefit from annual mammographic screening of BRCA mutation carriers at age 25 to 29 years; the net benefit would be zero or small at age 30 to 34 years, but there should be some net benefit at age 35 or older," the authors conclude.