HRT and breast cancer risk, in proportion

Breast cancer is the worry that stops more women considering HRT than any other. The honest position is that there is a small increase in risk with some types of HRT, that it is smaller than many people fear, and that it has to be weighed against real benefits. This article lays out the numbers plainly so you can think about them clearly.

These are population figures to give you a sense of scale. Your own risk depends on your history, and that is what an assessment is for.

What the risk actually is

For combined HRT, oestrogen plus progesterone taken by a woman with a womb, the best estimate is around five extra cases of breast cancer per thousand women over about seven and a half years of use. To put that the other way around, the large majority of women who take combined HRT will not develop breast cancer because of it. The risk is real, but it is small in absolute terms.

The type of HRT matters

The risk is not the same for every kind of HRT. Oestrogen-only HRT, taken by women who have had a hysterectomy, carries little or no additional breast cancer risk, and by some measures may slightly lower it. The small increase is associated mainly with the combined regimens, and the type of progestogen used appears to matter, with micronised progesterone looking more favourable than older synthetic ones. This is part of why body-identical HRT is the usual choice.

Putting it next to everyday risks

The added risk from combined HRT is in a similar range to some ordinary lifestyle factors. Drinking a couple of glasses of wine a day, carrying excess weight, or being physically inactive each raise breast cancer risk by a broadly comparable amount. This is not to dismiss the HRT risk, but to place it on the same scale as risks women weigh up all the time without alarm.

The risk falls when you stop

The increase in risk is linked to how long you use HRT and declines after you stop, returning towards your background level over the following years. It is not a permanent step up. This is one reason HRT is reviewed regularly rather than simply continued indefinitely without thought, so that the ongoing need is checked against the small ongoing risk.

The other side of the ledger

Risk is only half the picture. HRT is the most effective treatment for menopausal symptoms, and the relief it brings to quality of life, sleep and mood is significant for many women. Started within ten years of menopause it also helps maintain bone strength and reduces fracture risk. A sensible decision weighs the symptom relief and these benefits against the small, type-dependent risk, rather than looking at the risk in isolation.

Lowering your risk while on HRT

Whatever you decide, the everyday measures help: keeping alcohol modest, staying active, maintaining a healthy weight, and attending your breast screening appointments. Being breast aware and reporting any new lump or change promptly matters for every woman, on HRT or not. Regular review means your individual risk and benefit are reconsidered over time, not set once and forgotten.

How we work out your individual risk

The population figures give you a sense of scale, but your own risk is what matters, and it is more than a single number. A close family history of breast cancer, your alcohol intake, your weight, your breast density and your age all feed into it. Some of these you can change and some you cannot, but together they shape whether the small added risk from combined HRT is one you are comfortable with.

This is the conversation an assessment is built around. The aim is not to talk you into or out of HRT, but to set the type-dependent risk next to the benefit you would expect from treatment, so the decision is yours and it is informed. We review it again at least once a year, because both your symptoms and your risk factors change over time.

The honest summary

HRT carries a small increase in breast cancer risk that depends on the type, is comparable to common lifestyle factors, and falls after stopping. For most women with troublesome symptoms, that risk is outweighed by the benefits, but the right answer is personal and depends on your history. The point of laying out the numbers is to let you decide with facts rather than fear.

Ready to start?

If you want to move from reading to acting, the next step is a short assessment with a doctor on the GMC GP Register. It takes about ten minutes and tells you whether HRT is right for you.

Begin your assessment at this link. Online or in person at Westfield London.