Oestrogen-only hormone therapy may protect against breast cancer 

National women’s health organisation, the Jean Hailes Foundation for Women’s Health, reports on new evidence showing the risk of breast cancer is not increased for women on oestrogen-alone hormone therapy.

The latest news from the American Women’s Health Initiative provides greater clarity on the risks and benefits of hormone therapy. It shows women who have had hysterectomies and who use oestrogen-alone for menopausal symptoms are not at greater risk of breast cancer.

In fact, they may be protected from some forms of breast cancer. The study found oestrogen-alone hormone therapy “does not increase breast cancer incidence in postmenopausal women with hysterectomy, and may decrease the risk of early stage disease and ductal carcinomas”.

The findings were announced in the April 12 issue of the Journal of the American Medical Association (JAMA).

This information is relevant to more than 30,000 Australian women who have a hysterectomy each year. Hysterectomy is the surgical removal of the uterus or womb.

The findings are a direct contrast to the combined hormone therapy findings from 2002, which revealed a small but significant increased incidence of breast cancer in women who had used hormone therapy prior to commencing in the study, though there was no significant increase in risk in those who had not used hormone therapy beforehand. (see backgrounder, below)

Professor Helena Teede, Director of Research at the Foundation says: “This is reassuring for both clinicians and for women who have had a hysterectomy, when considering or using hormone therapy. This information needs to be considered in combination with additional individualised advice from their doctors to explain their risks and benefits.”

“I must emphasise these results are directly relevant only to women who have had hysterectomies. For women with a uterus considering, or currently taking hormone therapy, progesterone is necessary to protect their uterus from cancer,” Prof Teede says.

The Jean Hailes Foundation for Women’s Health supports the authors’ recommendations, and reconfirms short-term use of hormone therapy for the management of moderate to severe menopausal symptoms.

Backgrounder:

The Women’s Health Initiative (WHI) was a large study with two arms focusing on hormone therapy (HT). It began in the US in 1997 and looked at the long-term use of oral hormone therapy in women aged 50-79 years for the prevention of heart disease. The combined oral oestrogen plus progestin therapy arm of the study was stopped in 2002 after women had been monitored for five years. It stopped when researchers found a slightly greater rate of breast cancer in the women taking oestrogen-progestin HT, although the increase was seen only in women who had been prior users of hormone therapy before starting in the study.

In 2004, the oestrogen-only arm of the WHI was stopped after seven years – a year ahead of schedule - because a beneficial effect of hormone therapy on heart disease risk was not found. They did, however, reveal a small increase in the incidence of strokes, primarily in those participants who were over 60 years of age at commencement. Researchers also found no increase in breast cancer risk. The latest results confirm these findings and offer some good news for women taking oestrogen-only HT.

For more information please contact:

Aleeza Zohar – media communications (03) 9562 6771 or 0425 758 729

Page created April 12, 2006
Content April 12, 2006