HRT and Breast Cancer: Understanding the Risks and Benefits
HRT and Breast Cancer: Understanding the Risks and Benefits
Menopause can bring a range of challenging symptoms, and for many women, hormone replacement therapy (HRT) is the most effective treatment. However, concerns about breast cancer risk often leave women uncertain about whether HRT is a safe option for them. Understanding the difference between relative risk and absolute risk can help clarify what the evidence actually says about HRT and breast cancer.
Does HRT Increase the Risk of Breast Cancer?
It is widely reported that HRT can increase the risk of breast cancer, but the level of risk depends on multiple factors, including the type of HRT, the duration of use, and individual risk factors such as genetics and lifestyle.
It’s important to look at risk in two ways:
Absolute risk – The actual number of additional cases occurring in a group of people.
Relative risk – A comparison of risk between two groups, such as HRT users and non-users.
Relative Risk vs. Absolute Risk: A Key Distinction
Statistics can sometimes be misleading if relative risk is emphasized without understanding the absolute risk. Let’s break this down with a clear example.
A common statistic used in research shows that for women aged 50–59, the approximate number of women developing breast cancer over the next five years who will develop breast cancer is 24 cases per 1,000, taking all types of HRT will increase that number to 27 cases per 1,000 women.
Relative risk increase: The additional 3 cases per 1,000 women is a 12.5% relative increase (27 is 12.5% higher than 24).
Absolute risk increase: The actual increase is only 3 additional cases per 1,000 women, or 0.3% per woman.
While a 12.5% relative increase might sound concerning, the absolute increase is small, meaning that for most women, the added risk is very low in real terms.
What About Different Types of HRT?
HRT comes in various forms, and the type used can influence breast cancer risk.
Oestrogen-only HRT (for women who have had a hysterectomy) does not increase breast cancer risk.
Combined HRT (estrogen + progesterone) is associated with a small increase in breast cancer risk, but this risk disappears once HRT is stopped.
Micronised progesterone (Utrogestan) is considered the most ‘breast-friendly’ progesterone and there is not evidence it increase your risk of breast cancer for the first five years of treatment
Understanding the Context: Other Risk Factors for Breast Cancer
To put HRT risk into perspective, other lifestyle factors contribute to breast cancer risk as well:
Drinking two or more units of alcohol per day ( a large glass of wine) increases breast cancer risk by about 5 additional cases per 1,000 women – more than the increase linked to HRT.
Being overweight after menopause is associated with a higher risk than HRT- 24 additional cases per 1,000 women
Regular exercise and a healthy diet can help reduce breast cancer risk- 7 less cases per 1,000 women
Should You Avoid HRT Because of Breast Cancer Risk?
The decision to take HRT should be based on a balance of benefits and risks.
HRT is the most effective treatment for menopause symptoms such as hot flushes, night sweats, sleep disturbances, and mood changes.
It provides long-term benefits for bone health, reducing the risk of osteoporosis and fractures.
HRT can also lower the risk of heart disease and type 2 diabetes when started early.
For many women, the benefits of taking HRT far outweigh the small absolute risk increase in breast cancer.
Final Thoughts
When considering HRT, it’s important to:
Understand the difference between absolute and relative risk – while relative risk figures may sound high, the actual absolute increase is often very small.
Look at the bigger picture – other factors like weight, alcohol consumption, and lifestyle choices play a much larger role in breast cancer risk.
Have an informed discussion with your doctor – if you are concerned, discuss your personal risk factors and options for different types of HRT.
Ultimately, HRT remains a safe and effective option for many women, and the decision should be based on individual needs rather than fear-driven headlines. By understanding the real risks in context, you can make the best choice for your long-term health and well-being.