(NaturalNews) Hormone replacement therapy (HRT) increases women’s risk of lobular breast cancer by four times after only three years, according to a study published in the journal Cancer Epidemiology, Biomarkers and Prevention.
“Previous research indicated that five or more years of combined hormone-therapy use was necessary to increase overall breast cancer risk,” said lead researcher Christopher Li of the Fred Hutchinson Cancer Research Center. “Our study … suggests that a significantly shorter length of exposure to such hormones may confer an increased risk.”
Researchers suggested that the longer time period found in prior studies arose from the fact that those studies looked only at breast cancer in general, while the current study looked specifically at lobular cancers.
Lobular breast cancer accounts for approximately 10 percent of invasive breast cancers, while ductal breast cancer, in which tumors form in the breast’s milk ducts, accounts for much of the rest.
In the current study, researchers questioned 1,500 post-menopausal women in western Washington about their use of HRT. Women who were currently taking HRT had three times the cancer rate as women who were not undergoing the therapy. Those who had been taking HRT drugs for three years or more had four times the risk.
The researchers noted that the occurrence of lobular cancer in the United States increased by 52 percent between 1987 and 1999, while the incidence of ductal-lobular cancer rose by 96 percent. In the same time period, the occurrence of ductal cancer rose by only 3 percent.
In 2002, the results of the Women’s Health Initiative study first showed a link between HRT and increased breast cancer risk, leading to a sharp drop in the prevalence of HRT. Between 2001 and 2004, the researchers noted, breast cancer rates in the United States fell by 8.6 percent.
Health professionals say that younger menopausal women who are experiencing severe symptoms should still use HRT, because doctors now know to use lower doses for short time periods.
