Tag Archives: menopausal women

HRT linked to breast cancer

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Post-menopausal women should think twice before going in for hormone replacement therapy (HRT) because it is tied to breast cancer globally, reveals a study.

The study by McMaster University researchers, that found consistent evidence that use of HRT is linked to breast cancer globally, comes at a time when more women are asking for this medication to control hot flashes and other symptoms of menopause.

The rising trend is at odds with a US Women’s Health Initiative (WHI) study of 2002 which found a higher incidence of breast cancer, heart attack and stroke among women using HRT, the Journal of Epidemiology and Community Health reported.

Those findings led to a rapid decline in HRT use and a subsequent reduction in the incidence of breast cancer in many countries. However, HRT is now being offered to women in smaller doses and for a shorter period of time, according to a university statement.

Breast cancer

Breast cancer

McMaster researchers found convincing evidence for a direct association between decreased HRT use after the WHI study and the declining incidence of breast cancer.

“In our study we examined all studies that have reported breast cancer and rates of HRT use after the WHI study,” said Kevin Zbuk, assistant professor of oncology at the Michael G. DeGroote School of Medicine at McMaster, who led the study.


There is very clear evidence that the countries with the highest HRT rates had the largest decrease in breast cancer incidence when HRT use started to decline.

“Given the potential harms associated with HRT use, physicians and patients alike should be reminded of the lessons learned from the WHI trial. If HRT is needed, it should be used for the shortest time and at the lowest dose necessary to relieve symptoms,” concluded Zbuk.

Hormone link to breast cancer

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Raised levels of several hormones can triple the risk of breast cancer in post-menopausal women, a study has shown.

Scientists looked at the combined effect of multiple sex and growth hormones on a woman’s cancer chances.

They found that one hormone at higher than normal levels increased the breast cancer risk by 10% compared with having no elevated hormones.

But the risk for women with five or six hormones at raised levels was doubled, while having seven or eight tripled the odds of getting cancer.

The US researchers compared levels of eight hormones in blood samples collected from 33,000 nurses aged 43 to 69.

They included different types of oestrogen, testosterone and other “male” hormones, or androgens, and prolactin which stimulates the production of breast milk.

Levels of the growth hormone IGF-1 (insulin-like growth factor 1) and c-peptide, a biomarker for insulin, were also measured. Insulin acts as growth hormone as well as regulating the body’s use of sugar.

Breast cancer

Breast cancer

Over a period of nine years, the scientists identified 320 post-menopausal women who were diagnosed with breast cancer and not on hormone-replacement therapy.

Hormone levels in the cancer patients were matched against those of women who did not develop the disease.

The findings, published today in the journal Breast Cancer Research, showed that “ER positive” breast cancers with molecular receptors sensitive to oestrogen were the most influenced by hormone levels.

Study leader Dr Shelley Tworoger, from Brigham and Women’s Hospital in Boston, said: “Elevated oestrogens had the biggest effect on risk, especially for ER positive (oestrogen-sensitive) cancer. However, androgens, and prolactin also contribute to increasing risk of breast cancer.


“These hormones are known to stimulate the growth of breast cancer cells in the lab and, while androgens can be converted to oestrogen in the body, these hormones have also been found to stimulate cancer cell growth in the absence of ER (oestrogen receptors). Our results suggest that models used to assess breast cancer risk could be improved by taking into account multiple sex hormone and growth hormone levels.”

Women were ranked according to the number of hormones they had above average levels for their age.

On an individual basis, the highest levels of circulating oestrogens, prolactin or androgens roughly doubled the normal risk of breast cancer.

However the number of different hormones at raised levels also had a significant impact on risk.

Women with no hormones above average levels had a “substantially lower” risk of cancer, the study found.