Hormone Replacement Therapy Linked to Breast Cancer
Adding to evidence that hormone replacement therapy (HRT) can potentially raise a woman's risk of breast cancer, a new US study links recent, long-term HRT with a heightened risk of the disease.
Researchers found that HRT with estrogen alone or estrogen-plus-progestin was associated with a 70% increase in breast cancer risk when the therapy was taken for 5 years within the 6 years preceding the cancer diagnosis.
The findings build on previous research showing a link between long-term HRT and breast cancer and help clear up the question of whether combination HRT and estrogen-only HRT carry similar risks.
In addition, the study of about 1,300 women found that HRT use had a particular link to lobular breast cancer, the form of the disease that begins in the breast's lobules. It is far less common than ductal breast cancer, which begins in the milk ducts.
Women who were recent, long-time users of HRT faced a three-fold risk of lobular cancer compared with women who never used HRT.
These women also had about a 50% increase in the risk of ductal cancer.
