KVA
31st October 2023
Helen Newman, Healthcare Director

Hormone replacement therapy in women with breast cancer – what next?

Hormone replacement therapy (HRT) is widely used and celebrated amongst the general female population. There has been much debate over the benefits and risks of HRT and there remains confusion about who these therapies are suitable for.

As we know, HRT aims to help supplement women with hormones that are lost during the menopausal transition. These therapies may help to relieve the symptoms associated with menopause, such as:1

  • Hot flushes and night sweats
  • Genital dryness, burning and irritation
  • Painful urination and urinary tract infections
  • Prevention of osteoporosis

In Breast Cancer Awareness month, we ask where do women who have come through breast cancer fit? Especially younger women who have recovered and then move towards menopause, as well as those who experience menopause or menopausal-like symptoms during treatment for their breast cancer.

A recent UK study demonstrated that HRT use was associated with an increased risk of breast cancer by approximately x1.21 compared with women who had never used HRT. This increase was most attributable to oestrogen-progesterone therapy, with therapies uniquely consisting of oestrogen only showing a very small risk increase (x1.06).2 

As a result of this increased risk in breast cancer, oral or transdermal (systemic administration through the skin) oestrogen-based therapies must not be taken in women with a known, suspected or a history of breast cancer, or in those with a history of other oestrogen-based cancers (such as uterine cancer).1

So, what is available for these women who are advised not to take any HRT for their menopausal symptoms? Are there any hormone therapies that can be used for these women?

The answer is yes… while oral and transdermal HRTs are contraindicated due to their potential risks, women with breast cancer or a history of the condition can use transvaginal-based oestrogen creams as they hardly increase oestrogen levels in the bloodstream.1,2 In addition, transvaginal-based oestrogen therapies have not been associated with an increased risk of breast cancer.2

Studies have shown that vaginal oestrogen creams are effective in alleviating some vaginal symptoms and they tend to be generally well tolerated. However, it is important to note that oestrogen creams will not address the whole-body symptoms associated with the menopause, such as hot flushes or mood swings.3,4   

So while women with breast cancer or a history of the disease are not suitable for HRT, they can still use effective topical oestrogen creams that reduce some menopause-type symptoms.1–4

Nevertheless, there remains an unmet need to develop specific medications that can also reduce systemic menopause symptoms for these brave women, without increasing their risk of breast cancer. Let’s continue to support and acknowledge these women as we approach the end of the month and keep working towards the development of novel, effective and well tolerated therapies.

 

 References:

  1. Harper-Harrison G, Shanahan M. Hormone Replacement Therapy. Treasure Island (FL): StatPearls Publishing. 2023.
  2. Vinogradova Y et al. BMJ. 2020;28:371:m3873.
  3. Biehl C et al. Menopause. 2019;26(4):431–453.
  4. NHS. Available at:https://www.nhs.uk/medicines/hormone-replacement-therapy-hrt/vaginal-oestrogen/about-vaginal-oestrogen/. Date accessed: October 2023.