Researchers at Fred Hutchinson Cancer Research Center in Seattle compared 537 women ages 50 and older who had had breast cancer (diagnosed between 1988 and 1990) with 492 similar women who did not have the disease. They found a 2.6-fold higher incidence of lobular breast cancer among women who had taken hormone replacement therapy containing estrogen and progestin for at least six months; their HRT use averaged four years. The majority of breast cancer cases occur in the ducts, which carry milk to the nipple. The lobules produce the milk. Only about 10 percent of breast cancers are lobular cancers. The findings, researchers say, make them wonder if certain women carry characteristics that may make them more vulnerable to lobular cancer when using HRT. Lead researcher Dr. Christopher Li says there was a 35 percent increase in lobular cancer from 1988 to 1995. Other studies, including two published earlier this year, also found a connection between combination HRT and breast cancer, but there was no link among women who just took estrogen and breast cancer risk.
SOURCE/REFERENCE: Cancer, June 1, 2000
