Breast Cancer

Hormone replacement therapy and breast cancer risk

Hormone replacement therapy (HRT), also called oestrogen replacement therapy, menopausal hormone therapy, or post-menopausal hormone therapy, can effectively treat menopausal symptoms. Still, it’s essential to know that some types of HRT can increase your risk of breast cancer. HRT also can increase your risk of cancer returning (recurrence) if you’ve been diagnosed with breast cancer. Because of this risk, doctors usually recommend that women with a history of breast cancer not take types of HRT that affect the entire body (called systemic HRT). HRT has also been linked to cardiovascular risks, such as heart disease, stroke, and blood clots. However, all these risks vary and depend on many factors, including the type of HRT, the dose you take, your age when you start taking it, and how long you use it.

How we help

At Abbey Menopause, we can offer a lifestyle consultation to support you in making changes towards healthier living that will benefit you for years to come. Whether it helps with weight loss, exercise advice, sleep or exploring psychosexual problems, one of our clinicians will be able to help you. We use CBT and life coaching techniques to help you explore why these changes have been challenging to make or maintain in the past and to help develop achievable goals for the future. In addition, we can offer a general health screening blood test.

Does HRT increase my risk of developing breast cancer?

It depends on the type of HRT that you are taking.

Women without a womb (who have had a hysterectomy) may not need combined HRT and may be able to take oestrogen independently.

This does depend on the reason for the hysterectomy- women who have had severe endometriosis are likely to need two hormones for a time, even though they have no womb.

Oestrogen alone is not thought to incur any additional risk of breast cancer over five years.

The progestogen element of combined HRT has been shown to increase the risk of breast cancer to a minimal degree. This risk depends on the type of progesterone used- the risk is greater with synthetic progestogens and less with body-identical preparations.

The risk of developing breast cancer if you drink a glass of wine a night or are overweight is higher than the risk of breast cancer from taking HRT.

Smoking also increases your risk, and regular exercise reduces the risk of developing breast cancer.

It is important to remember that if a woman develops breast cancer, it is unlikely to be because they took HRT. For women with a low background risk of developing breast cancer (most of the population), the benefits of taking HRT for up to 5 years are likely to outweigh the risks.

Can I take HRT if I have had breast cancer myself?

The discussion around taking HRT after you have had breast cancer yourself is different from discussing the additional risk of developing breast cancer from taking HRT if you have never had breast cancer.

Many current treatments used to treat breast cancer block oestrogen and cause a woman to experience menopausal symptoms. Women are often advised to stay on these medications for many years.

Unfortunately, we do not have many studies looking at the risk of breast cancer recurrence when taking HRT, and our studies have been criticised. However, our studies show a small increased risk of recurrence of breast cancer in women taking HRT after breast cancer, and current guidance is that HRT is contraindicated in women with a history of breast cancer.

It is important to remember that a lack of solid evidence does not mean a lack of harm. The decision to take HRT following treatment for breast cancer needs to involve the cancer and breast teams and a menopause specialist. Changes may be made to a woman’s current breast cancer treatment that can improve menopausal symptoms.

Both pharmacological (medication) and non-pharmacological alternative therapies can effectively manage menopausal symptoms and are usually recommended first-line.

Vaginal irritation and dryness are common symptoms, which can be quite disabling and may not respond to moisturisers and lubricants. In these circumstances, a low dose of vaginal oestrogen can be highly effective and safe, as barely any oestrogen is absorbed around the body.

An important message here is that every case needs to be managed individually as the type, stage and grade of breast cancer changes the risk of a recurrence, along with the fact that the severity of a woman’s symptoms and response to other non-hormonal treatments varies. Shared decision-making is vital, and it is essential that every woman feels listened to and can fully explore treatment options and discuss the pros and cons with a specialist, thereby feeling fully informed and comfortable with any decision that is made around treatment.

Occasionally, a trial of HRT after breast cancer is the right decision for that individual due to the severity of symptoms and the impact of these symptoms on quality of life. This decision is generally made in a multi-disciplinary team setting after non-hormonal options have been explored and the risks of HRT have been carefully outlined and discussed.

Not if you have premature ovarian insufficiency or early menopause, we replace hormones you lost too early. We only start counting ‘years on HRT’ from the age of the natural menopause, around age 51. If you have had to start it at a younger age, the’ extra’ years on HRT are not thought to incur a cumulative risk of breast cancer.

What if I have a Family history of breast cancer?

Many women will have a relative with breast cancer because it is relatively standard.

It depends on the strength of the family history of certain cancers. For many women with a family history of breast cancer, this will not change their background risk of developing breast cancer much, and taking HRT is unlikely to contribute much to that risk.

In these women (the majority), the benefits of taking HRT will likely outweigh the risks.

Women with multiple family members or close family members who had breast cancer at a young age may require advice from the genetics team before they start HRT.