"The finding they report is consistent with [previous] observations that suggested there was a drop in incidence of breast cancer in about 2003 and it coincided with when the Women's Health Initiative reported that estrogen-plus-progesterone use was associated with an increased risk of heart attacks as well as a slight increased incidence of breast cancer risk," said Dr. James Liu, chairman of obstetrics and gynecology at MacDonald Women's Hospital, Case Medical Center, University Hospitals in Cleveland. "The association caused many women to either question their need to be on [hormone therapy] or stopping it."
But, cautioned Liu, "the data is not strong enough to say this observation was caused by [a decline in hormone use] but it is a very strong association."
There's more on hormone therapy and cancer at the U.S. National Cancer Institute.
SOURCES: Diana Miglioretti, Ph.D., senior investigator, Group Health Research Institute, Seattle; Jay Brooks, M.D., chairman, hematology/oncology, Ochsner Health System, Baton Rouge, La.; James Liu, M.D., chairman, department of obstetrics and gynecology, MacDonald Women's Hospital, Case Medical Center, University Hospitals, Cleveland; November 2009, Cancer Epidemiology, Biomarkers & Prevention