TUESDAY, Sept. 23, 2008 (HealthDay News) -- Postmenopausal women carrying breast cancer-linked BRCA gene mutations who took hormone replacement therapy actually reduced their risk for breast cancer, researchers report.
The study's authors called the finding "reassuring."
"I have no reservation about recommending HRT to my patients who have a [BRCA] mutation and who have had an oopherectomy [removal of ovaries] and, particularly, young women with surgical menopause," stated Dr. Steven Narod, senior author of the study and chair of breast cancer research at Women's College Hospital in Toronto. "I feel completely, absolutely, 100 percent comfortable in recommending HRT to BRCA carriers."
The study was published in the Sept. 23 issue of the Journal of the National Cancer Institute.
In a prepared statement, Dr. Amos Pines, immediate past president of the International Menopause Society (IMS), said the results support "the IMS view that HRT in the early postmenopausal period is safe and may be prescribed without concerns when needed."
Other commentators, however, approached the subject more conservatively, including IMS Secretary General Dr. Regine Sitruk-Ware.
"Given the limitations of the design and size of the study, caution is still recommended for the use of HRT in women who are carriers of a genetic mutation that expose them to a higher risk of breast cancer in their life," Sitruk-Ware said, also in a prepared statement.
Another expert agreed.
"These observational studies are small and have misled before," said Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La. "I would still advise my patients who have a mutational BRCA status, if at all possible, to use as little exogenous estrogen as possible and for as little time as possible."
Some 3 percent of invasive cancers can be attributed to either a BRCA 1 or BRCA 2 gene mutation, which elevate a woman's lifetime risk of developing breast cancer to 60 percent to 80 percent. The National Cancer Institute puts the lifetime risk of developing breast cancer for an average American woman at 12.7 percent.
Many women with a BRCA mutation elect to have their ovaries removed at a relatively young age to reduce their breast cancer risk.
For this matched case-control study, researchers analyzed tumor samples from 472 postmenopausal women with a BRCA 1 mutation, some of who had undergone endocrine therapy (removing estrogen) before surgery for breast cancer. The other women also carried the BRCA1 mutation but had no history of breast cancer.
Women who had used HRT at some point in their lives had a 42 percent reduced risk of developing breast cancer compared with women who had never used hormone therapy, the researchers found.
Women who had undergone surgical menopause seemed to experience a greater risk reduction than women who had undergone natural menopause, the team noted.
It's not clear what mechanism is at play here, except that women with BRCA mutations are more likely to develop estrogen-receptor negative cancers, which are not fueled by estrogen.
A second study in the same issue of the journal describes a model, the preoperative endocrine prognostic index (PEP), which predicts the risk of relapse in women who have breast cancer.
This information should help clinicians identify appropriate treatments for individual patients, said researchers led by Matthew Ellis, of Washington University School of Medicine in St. Louis.
There's more on the BRCA 1 and BRCA 2 mutations at the National Cancer Institute.