Hormone replacement therapy increases breast cancer risk of death in postmenopausal women

The latest Women's Health Initiative study show that hormone therapy is associated with an increased the risk of death from breast cancer, as well as an increased risk of developing invasive breast cancer in postmenopausal women.

Women taking estrogen plus progestin are more likely to die from breast cancer and from other causes than women who did not take these hormones.  Also the breast cancers in these women had more lymph node involvement, which generally leads to a higher mortality rate and poorer prognosis.  Results showed that combined hormone therapy increases the incidence of invasive breast cancer and that, more commonly, the cancers had spread to the lymph nodes. There also were more deaths attributed to breast cancer in those taking hormone therapy. There also were more deaths from all causes in the women who had been diagnosed with breast cancer who were on hormone therapy.  The study also found that hormone therapy interfered with detection of breast cancer, leading to cancers being diagnosed at a more advanced stage.