Many women fear getting breast cancer, and now a newly identified set of genes may help predict which women at high risk could benefit from preventive medication.
A study by Northwestern Medicine is helping discern whether a woman at high risk is more likely to develop either hormone receptor-positive breast cancer or hormone receptor-negative breast cancer. Until now, it has not been possible to predict which type of breast cancer a high-risk woman might develop.
But the distinction is important because breast cancer prevention drugs like tamoxifen and raloxifene are effective only against breast cancer that is sensitive to estrogen — hormone receptor-positive breast cancer. The drugs don’t prevent breast cancer that is not sensitive to estrogen — hormone receptor-negative breast cancer, which is more common in young women and African American women.
Yet some women at high risk take the drugs not knowing if they will actually work, while other women opt not to take the drugs because of possible side effects. This new study may help women at high risk of breast cancer make a more informed decision about taking preventive medications.
"We now have the possibility of predicting if a preventive drug will work for a woman at high risk of breast cancer, so that we don't expose women to the risks and side effects of this drug if it won't help them," said Seema Khan, M.D., senior author of the study, published March 19, 2013, in the journal Cancer Prevention Research.
The newly discovered genes, many of which are involved in fat metabolism, were present at a higher level in the healthy breasts of women with hormone receptor-negative breast cancer.
The genes also provide potential targets to develop preventive therapy for hormone receptor-negative breast cancer, said Khan, who is co-leader of the breast cancer program at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University. "Once we understand what regulates these genes,” Khan said, “we can try to develop a therapy to switch them off."
Are you at high risk of breast cancer and taking preventive medication? Share your experience in the comments.