Can I take HRT if I have a history of breast cancer?

Breast cancer is the second most common type of cancer in the UK: about one in seven women will develop the disease over their lifetime [1].

And what about HRT and breast cancer? If you have had breast cancer and are wondering whether you can take hormone replacement therapy (HRT) for menopausal symptoms and future health, this guide is for you.

The average age a woman in the UK experiences menopause is 51 [2]. However, it can occur earlier or later than this – health conditions, genetics, ethnicity and your socioeconomic background can influence the age you experience it, as well as treatment for cancer.

Your menopause may occur at a younger age as some treatments for cancer, such as chemotherapy or radiotherapy, affect ovarian function resulting in hormone levels reducing. This might be a permanent or temporary menopause depending on the type of treatment you have.

Can I be prescribed HRT if I have a history of breast cancer?

NICE guidance on early and locally advanced breast cancer states HRT should not be routinely offered women with menopausal symptoms and a history of breast cancer [3]. In exceptional circumstances, it adds, HRT can be offered to women with severe menopausal symptoms and with whom the associated risks have been discussed.

Some women may choose to accept an increased risk of relapse in exchange for relief from menopausal symptoms and an improved quality of life, and that preferences may vary according to individual circumstances and the absolute risk of relapse, which is uncertain due to lack of solid evidence and research in this area.

The lack of evidence from prospective studies and randomised controlled trials highlights the importance of shared decision making in this highly complex area.

HRT and breast cancer: what does the research show about HRT in women who have had breast cancer?

The research that has been undertaken regarding taking HRT after breast cancer shows conflicting results: many studies are of poor quality and so the results are difficult to interpret properly. In addition, the studies have often involved older formulations of HRT to the types often prescribed now.

Since 1980, there have been 26 studies published on this area (25 studies have shown no increased risk and five showed benefit; four reported decreased mortality) [4,5]. Only one, the Hormone Replacement After Breast Cancer – Is It Safe? (HABITS) trial, reported an increased risk of local recurrence, but not metastatic disease or breast cancer death [6]. This study also used older and synthetic types of HRT.

There is a lack of robust evidence on giving HRT and testosterone to women who have had a history of breast cancer and their risk of recurrence. There is some evidence that testosterone may be beneficial for women who have had breast cancer [7]. However, some women choose to take HRT and/or testosterone as their quality of life is suffering without it. They are also keen to obtain the future health benefits of taking natural, body identical HRT, as women who take HRT have a lower future risk of osteoporosis, diabetes, coronary heart disease, clinical depression, dementia and also some cancers [8].

What is key is that all treatment decisions are based on your individual circumstances, and if you decide you may want to take hormonal treatment, this should be a shared decision-making process with you and your healthcare team.

There are different types and doses of hormones. Testosterone has been shown in some studies to be beneficial to women who have had breast cancer, including those women who are also taking an aromatase inhibitor [9,10].

Hormones used in HRT are much lower that the doses of hormones in contraceptives and they are also natural (they are synthetic in all contraceptives) – so the same chemical structure as the hormones you produce when you are younger. They are also short acting in your body, so do not build up with time.

Some women decide to take HRT for a few months and then assess how they are feeling and how many of their symptoms improve. They feel reassured knowing that they can stop taking HRT at any time and the hormones will all be out of their body within a day of stopping them.

What are the risks of systemic HRT if I’ve had breast cancer?

It is not possible to quantify risks as they vary between different people and are likely to be different for different types of breast cancer in the past too. If you have had breast cancer, your healthcare team should explain any potential individual risks when it comes to taking HRT, so you can weigh up the pros and cons of any decisions around possible treatment.

It’s important you are informed about benefits and any potential risks and how treatment might impact your quality of life and future health, so you have enough information to make an informed decision.

Ductal Carcinoma in Situ (DCIS) and Lobular Carcinoma in Situ (LCIS)

It is unlikely that women taking HRT after DCIS and LCIS have increased risks, however studies have not been undertaken in this area.

ER-negative breast cancer

If you have had an ER-negative breast cancer in the past, then some women consider taking HRT as this cancer does not have receptors for oestrogen in it and so taking HRT is unlikely to be detrimental to future health or risk.

ER-positive breast cancer

If you have ER-positive breast cancer, you should talk to healthcare professionals who are experts in treating people for the menopause after breast cancer – it’s usually advisable to talk to a menopause specialist, as well as a breast specialist oncologist to talk about your individual circumstances.

HRT and aromatase inhibitors and tamoxifen

Tamoxifen works differently in different women and does not block oestrogen throughout your body. Research has shown that some women who take tamoxifen actually have more oestradiol in their bodies than women who do not take tamoxifen [11]. Some women take HRT with tamoxifen with benefit to both their symptoms and their future health.

Taking HRT containing oestrogen will not usually have any benefit to your symptoms if you are taking an aromatase inhibitor. However, some women take testosterone with their aromatase inhibitor with beneficial effects to their symptoms and possibly their future health [12].

Spotlight on vaginal hormones

Vaginal hormones, also known as local hormones, are different to systemic HRT as they are very low dose and do not get absorbed into your body. They can usually safely be prescribed for women who have had any type of breast cancer [13,14,15,16].

Vaginal hormones can improve symptoms of vaginal dryness, soreness, irritation, pain as well as improve urinary symptoms such as cystitis, recurrent urinary tract infections, increased frequency of passing urine, incontinence and urgency.

They can be given as an oestrogen pessary, vaginal tablet, gel, cream or ring, or as a daily pessary called prasterone. The prasterone pessary contains a hormone called dehydroepiandrosterone (DHEA), which converts to both oestrogen and testosterone in the vagina and surrounding tissues. Vaginal hormones can often be beneficial in women who take aromatase inhibitors or tamoxifen [17].

If you are wondering what treatment options are right for you, you can book an appointment to speak to a Newson Clinic clinician here.

References

1. Cancer Research UK: ‘Breast cancer statistics’
2. National institute for Health and Care Excellence (NICE) (2024), ‘Menopause: what is it?’
3. NICE (2024) ‘Menopause: identification and management’
4. Cold, S, Cold, F, Jensen, M, Cronin-Fenton,D, Christiansen, P, Ejlertsen, (2022), ‘Systemic or Vaginal Hormone Therapy After Early Breast Cancer: A Danish Observational Cohort Study’, JNCI: Journal of the National Cancer Institute. doi.org/10.1093/jnci/djac112
5. Bluming, A, (2022) ‘Hormone replacement therapy after breast cancer: it is time’, The Cancer Journal, 28 (3), pp. 183-90, doi: 10.1097/PPO.0000000000000595
6. Holmberg L, Anderson H, (2004), ‘HABITS steering and data monitoring committees. HABITS (hormonal replacement therapy after breast cancer–is it safe?), a randomised comparison: trial stopped’, Lancet, 7;363(9407) pp.453-5. doi: 10.1016/S0140-6736(04)15493-7. PMID: 14962527
7. Glaser R.L., York A.E., Dimitrakakis C. (2019), ‘Incidence of invasive breast cancer in women treated with testosterone implants: a prospective 10-year cohort study’, BMC Cancer, 19(1):1271. doi: 10.1186/s12885-019-6457-8
8. Gambacciani, M., Cagnacci, A., Lello, S. (2019), ‘Hormone replacement therapy and prevention of chronic conditions’, Climacteric, 22(3), 303–306. doi.org/10.1080/13697137.2018.1551347
9. Glaser R.L., Dimitrakakis C. (2013), ‘Reduced breast cancer incidence in women treated with subcutaneous testosterone, or testosterone with anastrozole: a prospective, observational study’, Maturitas, 76(4):342-9. doi: 10.1016/j.maturitas.2013.08.002
10. Glaser R., Dimitrakakis C. (2015), ‘Testosterone and breast cancer prevention’, Maturitas, 82(3):291-5. doi: 10.1016/j.maturitas.2015.06.002
11. Berliere M. et al. (2013), ‘Tamoxifen and ovarian function’, PLoS One. doi: 10.1371/journal.pone.0066616
12. Glaser R., Dimitrakakis C. (2015), ‘Testosterone and breast cancer prevention’, Maturitas, 82(3):291-5. doi: 10.1016/j.maturitas.2015.06.002. Epub 2015 Jun 24. PMID: 26160683.
13. Agrawal P. et al. (2023), ‘Safety of vaginal estrogen therapy for genitourinary syndrome of menopause in women with a history of breast cancer’, Obstet Gynecol,142(3):660-668. doi: 10.1097/AOG.0000000000005294
14. McVicker L. et al (2024), ‘Vaginal estrogen therapy use and survival in females with breast cancer’, JAMA Oncol, 10(1):103-108. doi: 10.1001/jamaoncol.2023.4508
15. The 2022 hormone therapy position statement of the North American Menopause Society advisory panel (2022), ‘the 2022 hormone therapy position statement of The North American Menopause Society’, Menopause, 29(7):767-794. doi: 10.1097/GME.0000000000002028
16. Hussain I., Talaulikar V.S. (2023), ‘A systematic review of randomised clinical trials – the safety of vaginal hormones and selective estrogen receptor modulators for the treatment of genitourinary menopausal symptoms in breast cancer survivors’, Post Reprod Health, 29(4):222-231. doi: 10.1177/20533691231208473
17. Mension E. et al (2022), ‘Safety of prasterone in breast cancer survivors treated with aromatase inhibitors: the VIBRA pilot study’, Climacteric, 25(5):476-482. doi: 10.1080/13697137.2022.2050208