Hormone replacement therapy has once again been demonstrated to be a risk factor for hormone-positive breast cancer but not for triple negative (estrogen negative, progestin negative, and Her2 negative.)
Some details from a study published in the August 10, 2010 issue of Cancer Epidemiology, Biomarkers & Prevention as part of the California Teachers Study:
• Combined estrogen-progestin therapy was far more toxic than estrogen therapy alone. Those with combined therapy faced an 83 percent increase in risk of breast cancer while those with estrogen alone fact a 19 percent increase.
• Continuous use was more risky than intermittent.
• Neither combined estrogen-progestin or estrogen alone significantly affected the risk of triple negativeRead more on Medpage.
Source: Saxena T et al. "Menopausal hormone therapy and subsequent risk of specific invasive breast cancer subtypes in the California Teachers Study" Cancer Epidemiol Biomarkers Prev 2010; DOI: 10.1158/1055-9965.EPI-10-0162.