The risk of breast cancer due to HRT during menopause is lower than previously feared

Taking hormone replacement therapy to help with menopause is less risky than previously thought, according to the largest study on this problem to date.

HRT was first associated with breast cancer in 2002 and since then the safety of the treatment has been questioned, causing confusion and concern among millions of women.

Last year, a large study from the University of Oxford suggested that HRT use increases the risk of breast cancer by a third and is responsible for about one in 20 cases of the disease in the UK.

While new research confirmed the link between the medication and breast cancer, it found it to be safer than previously suggested.

The study, based on data from more than half a million British women, showed that HRT use was associated with a 20 percent increased risk of breast cancer. But the overall risk remained very low, the scientists said.

For every 10,000 women who are using HRT, about 26 are likely to develop breast cancer as a result of the medication.

The study also found that when people stop taking HRT, the increased risk of breast cancer quickly returns to that of non-users.

About a million British women are on HRT, which can be taken in the form of gels, patches or pills and which provide estrogen when levels produced by the body decrease during menopause.

Lead author Dr Yana Vinogradova, from the University of Nottingham, said: “This is the largest study of its kind ever and we hope it will provide reassurance and clarity to women who are afraid of using HRT.

“Our findings show that the total number of women who develop breast cancer as a result of HRT is small.”

The study compared about 98,000 women aged 50 to 79 who were diagnosed with breast cancer between 1998 and 2018, compared to about 457,000 women of the same age who did not develop breast cancer.

Overall, 34 percent of those with breast cancer had used HRT, compared to 31 percent of those who did not get breast cancer.

The study found that combined estrogen-progesterone HRT, the most common form of treatment, was associated with the greatest increased risk of breast cancer, at 79 percent. However, once treatment was stopped, the risk almost returned to normal.

The increased risk for women treated with estrogen alone, given to people who have had hysterectomies, was 15 percent.

Doctors said the benefits of HRT in relieving debilitating symptoms – such as depression and hot flashes – often outweigh the small increased risk of breast cancer.

Professor Martin Marshall, President of the Royal College of GPs, said: “There is a lot of compelling evidence to suggest that HRT is safe and effective, and current clinical guidelines recommend it as an appropriate treatment for some menopausal women.

“We urge patients not to worry about this trial and to continue taking HRT as prescribed.”

Dr. Edward Morris, President of the Royal College of Obstetricians and Gynecologists, said: “Unfortunately, many women still suffer in silence and are reluctant to seek advice and support because of concerns about the risks of breast cancer and HRT.

“We encourage all women who are concerned about their symptoms or the medications they are taking to speak with their primary care physician.” The study is published today in the British Medical Journal.