Hormone therapy may cut breast cancer risk in some

A breast cancer cell

By Will Dunham

WASHINGTON (Reuters) - Hormone replacement therapy, which raises breast cancer risk for some women, appears to reduce the risk for those with a certain genetic mutation linked to the disease, researchers said on Tuesday.

Dr. Steven Narod of Women's College Hospital in Toronto and colleagues looked at hormone replacement therapy or HRT in post-menopausal women with a BRCA1 gene mutation that greatly increases their chances of developing breast cancer.

Among 472 women from nine countries, those who used HRT were 42 percent less likely to develop breast cancer than those who did not, Narod's team reported in the Journal of the National Cancer Institute.

Many women with a BRCA1 mutation choose to have their ovaries removed in order to reduce their risk of getting breast cancer, but the operation brings on menopause. HRT can relieve menopausal symptoms such as hot flashes and night sweats.

Earlier studies raised alarms about HRT because it raised the risk of breast cancer, stroke and other heart conditions.

But the impact on the risk of breast cancer in post-menopausal women with a BRCA1 gene mutation was unclear, Narod's team said.

Narod said the findings should reassure women with the mutation who want to have their ovaries removed before menopause to lower their risk of getting breast or ovarian cancer, but are worried about using HRT to relieve the symptoms that will follow.

"Certainly in my practice in Toronto at Women's College Hospital, I have no hesitance whatsoever in prescribing hormone replacement therapy to young women who have a BRCA1 mutation and surgical menopause," Narod said in a telephone interview.

"We want to be able to get the benefit of the ovariectomy in terms of preventing cancer but maintain the best quality of life. And we think that the best way to maintain the quality of life is to use hormone replacement therapy," Narod added.

Hormone replacement therapy can involve estrogen alone or estrogen along with progesterone or progestin, a synthetic hormone with effects like those of progesterone.

Narod found no difference in risk reduction between estrogen-only or estrogen-progesterone hormone therapies.

Not everyone was convinced. Two experts who wrote a commentary in the same journal accompanying the study said the findings "provide some evidence for safety but are insufficient to reliably inform routine clinical practice."

"As a result, continued caution in prescribing hormone therapy to women with BRCA1 mutations who are at high risk for breast cancers remains prudent," Dr. Rowan Chlebowski of University of California Los Angeles and Ross Prentice of the Fred Hutchinson Cancer Research Center in Seattle wrote.

(Editing by Maggie Fox and Cynthia Osterman)