The following is a list of articles and abstracts that address the risk of breast cancer with conventional hormone replacement therapy. The synthetic chemical, progestin, is often used as part of hormone replacement therapy and is thought to be the major culprit in the increased incidence of breast cancer.
Some of the following studies show a slight increase in the incidence of breast cancer with estrogen alone, others do not (even with up to fifteen years of use).
Estrogen versus Estrogen plus Progestin
Hormone Replacement Therapy, Risks and Benefits
The WHI Estrogen-Alone Trial
Million Women’s Study
The following review of ‘Post menopausal Hormone Replacement Therapy’ explains the benefits and
risks of conventional HRT which includes Progestins.