HRT and Risk of Breast Cancer

[Badri]

HRT was widely prescribed for women suffering from menopausal symptoms of hot flushes, sweating and depression. An International Study now finds that hormone replacement therapy for menopause is twice as likely to cause cancer as previously thought. Researchers say there is now about 3,000 cases of breast cancer in Britain each year, instead of the 1,400 previously cited. HRT was likely to be responsible for one million out of the 20 million breast cancer cases in western nations since 1990, the research said.

The study, published in The Lancet, analysed results from 58 studies following more than 500,000 women over a 26-year period. It revealed that cancer risk was not only raised while women were taking HRT but that they were at an increased risk for at least 10 to 15 years after treatment ceased.

There was an increased risk from all types of HRT but the more hormones that were taken, and the longer they were taken for, the greater their risk, it showed.

Doctors believed previously that any increased breast cancer risk largely fell away once treatment had stopped and that it was mainly confined to combined oestrogen and progesterone forms of HRT, instead of also affecting women taking oestrogen-only therapies.

The National Institute for Health and Care Excellence (Nice) previously recommended its use for menopause symptoms. It has now indicated that it was reviewing the guidelines and would take the new research into account. The UK medicines watchdog, the Medicines and Healthcare products Regulatory Agency (MHRA), issued a warning for women to “be vigilant for signs of breast cancer, even after stopping HRT”.

The latest study, an international collaboration led by Oxford University and funded by Cancer Research UK, found that 6.3 in every 100 women who had never taken HRT would get breast cancer over the 20 years from the ages of 50 to 69.

For women who took oestrogen and daily progesterone for five years, this increased to 8.3 in every 100, equivalent to an extra case of cancer for every 50 women taking HRT.

There was an extra case of cancer in every 70 women who took oestrogen with intermittent progesterone, typically 10 to 14 days per month, and an extra case in every 200 women who took oestrogen-only HRT.

These risks doubled for women who used HRT for ten years, but there appeared to be little or no risk in women who took the treatment for less than a year.

Although the study was observational, evidence from clinical trials suggested that the findings did show cause and effect, Paul Pharoah, professor of cancer epidemiology at Cambridge University, said.

Janice Rymer, vice-president of the Royal College of Obstetricians and Gynaecologists, said that women should bear in mind that HRT still had several health benefits, adding: “These findings should not put women off taking HRT if the benefits — such as protection of bones and decrease in cardiovascular risk — outweigh the risks.”

Based on a report by Rosie Taylor in The Times.