Hormone replacement therapy (HRT) and breast cancer risk

Hormone replacement therapy (HRT) is a combination of estrogens, with or without progestins, that can be prescribed during menopause to replace the physiological decline in these hormones. Dr. Elisa Llurba discussed the truths and myths surrounding this medical treatment in the article:“Hormone replacement therapy (HRT) during menopause: When is it necessary?, But… is there a link to breast cancer? Dr. Elisa Llurba tells us.

Some numbers

If we have 1,000 women between 50 and 60 years old, 23 of them will develop breast cancer in the next 5 years. If they take TSH, it has been shown that instead of 23, this number would be 27. That is, it does increase slightly (4 more women out of a total of 1,000). Although this risk is very low, it is important to note that the risk of death does not increase in the women who took it.

But it's very important to note that in women who only took estrogen without progestin (because for some reason they didn't have a uterus), this risk not only doesn't increase but actually decreases to 19 women per 1000 (4 fewer than the baseline risk). This suggests that estrogen appears to be protective. Therefore, the risk doesn't seem to be due to estrogen itself, but rather, if anything, is attributed to the progestin taken to prevent uterine bleeding and endometrial cancer. 

These studies have been done with synthetic progestins and now micronized progesterone is given orally or an intrauterine device with progesterone can also be inserted (it will protect the uterus without affecting the risk of cancer). 

This risk, however, is reduced if only one of the two HRT hormones is taken.

Comparing other risks

• In obese women, if we have 1000 women, the risk doubles, that is, from 23 to 47 women.
• Drinking two units of alcohol a day: we went from 23 women to 28
• Smoking increases from 23 to 26 women.

How can we reduce these figures? 

By exercising for two hours a week, the risk drops from 23 to 16 women. In other words, the slight risk of breast cancer that appears to be associated with combined hormone replacement therapy is clearly counteracted by lifestyle changes such as avoiding weight gain, avoiding toxins, and exercising for two hours a week.

Remember that when making a decision about whether or not to take HRT, a reduction in the risk of obesity, death from cardiovascular disease, osteoporosis, and probably dementia has been demonstrated.

We recommend that you bring all this information to the table when you consult a professional to assess whether HRT is right for you.

And if you have any questions about this, don't hesitate to contact us. beDona team