Does HRT cause Breast Cancer? We put the risks in to perspective...

Many women taking HRT will have been listening to the news over the last 48 hours worrying that their HRT is going to cause them to have breast cancer.

But do not worry, nothing has changed.

Dr Sally Louden - Menopause Specialist

Dr Sally Louden - Menopause Specialist

The data that has been published in the Lancet is old data, collected from 1992. It has included 58 studies, and looked at 110,00 women, of which 51,000 used HRT. The report showed an increase in breast cancer with HRT use, and the risk appeared to be higher with combined oestrogen/progesterone compounds, but was also increased slightly with oestrogen only preparations (used in women who have had a hysterectomy).

The risk of breast cancer remained slightly elevated for more than 10 years after stopping the HRT, and appeared to be related to the duration of use. Starting HRT between 40 and 50 years of age was also associated with an increased risk of breast cancer, but the numbers of women who were studied were very small.

Professor Janice Rymer, who is the Vice President of the College of Obstetricians and Gynaecologists,  said that women should be reassured that the findings of this study do not add anything new to the known effects of HRT. For most women, HRT relieves the dreadful symptoms of menopause and is safe. There is a small increase in the risk of breast cancer, but this needs to be weighed up against the benefits of taking the HRT to relieve the debilitating symptoms of the menopause, and the reduction in the risk of cardiovascular disease and the protection against osteoporosis. It must also be remembered that cardiovascular disease (heart attacks and strokes) kill far more women than breast cancer. It must also be remembered that a woman has a far greater risk of breast cancer if she is overweight, or drinks 2 units of alcohol each day, and that regular exercise offers a great protective effect.

It may be that continuous combined preparations (no bleed therapies) may be more of an issue in obese women, but this regime offers the best protection against endometrial cancer, of which rates are rising dramatically. The study did not look at micronized progestogen (utrogestran), which is a new plant based progestogen, that is thought to be the safest progestogen available. 

Ultimately, women taking HRT should be reviewed at least annually to reassess their risk profile with a blood pressure and weight assessment, to ensure they are on the lowest possible dose to control their symptoms, and that the HRT is stopped at an appropriate time. Women should ensure they take advantage of the three yearly mammogram screening whilst taking HRT, and if you are worried, talk to your doctor, who can give you individualized advice. 

Dr Sally Louden

August 2019

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