Hormone replacement therapy warning after rise in women referred for urgent womb cancer checks

Surging use of hormone replacement therapy (HRT) and risky high dose prescribing has triggered a rapid rise in women being sent for urgent cancer tests, says a report by Britain's top menopause specialists.

The drugs, given to alleviate some of the worst symptoms of the menopause, are safe and effective for the majority of women but can cause side effects including irregular bleeding.

Although common within the first six months of starting HRT, after that irregular bleeding in post-menopausal women can be a symptom of womb cancer so must be investigated without delay, NHS guidelines state.

Over the past three years, rising numbers of patients on HRT reporting irregular bleeding have resulted in a 43 per cent increase in patients being tested for womb cancer, the top women's health doctors have claimed.

Such is the concern that last week the British Menopause Society (BMS) issued new guidance on HRT prescribing and management of bleeding side effects.

Timothy Hillard, a consultant gynaecologist at University Hospitals Dorset NHS Trust, Poole and one of the authors of the new BMS guidance, said: 'These figures will come as no surprise to anyone working in gynaecology.'

Since 2018 there has been an explosion in demand for HRT driven by celebrity campaigners – including TV presenter Davina McCall – who have been pushing for greater awareness.

The number of patients being prescribed HRT in England rose by almost a third in just a year – from 1.8million in 2021 to 2.3million in 2022, according to official figures from the NHS Business Services Authority, leading to intermittent drug shortages.

Along with a general rise in the use of HRT, Mr Hillard said another reason bleeding is increasing is because women are being prescribed HRT at a younger age: during the perimenopause, the years prior to the menopause when hormones fluctuate.

'During this time, women are still having periods so there may be confusion about who requires an urgent referral to investigate bleeding,' he said.

'In post-menopausal women, there's a one in ten chance that irregular bleeding is a sign of cancer, but for younger women in perimenopause that risk is lower.' Part of the reason for new guidance – which has been drawn up with input from the Royal College of Obstetricians and Gynaecologists and other leading women's medical bodies – was to address that, so that patients were not referred for unnecessary investigations, he added.

The BMS guidance also cites 'an increasing tendency for off-licence prescribing of higher dose oestrogen with sub-optimal dosages of progestogen' as a reason for the problems.

HRT contains female hormones oestrogen and progesterone that wane in middle age.

Typically, women are prescribed oestrogen in patch, gel or spray form, and the drug is absorbed through the skin. Progesterone is usually given as a capsule.

Both hormones can be combined in a pill, too. Oestrogen is safe when prescribed within licensed doses but experts believe excessive amounts, along with insufficient doses of progesterone, cause the womb lining to thicken abnormally – known as endometrial hyperplasia.

This can lead to heavy bleeding and an increased risk of womb cancer, which is why it's necessary to investigate hyperplasia if it is discovered.

A Mail on Sunday investigation, published in April last year, revealed concerns about one private clinic, Newson Health, prescribing higher than licensed doses of HRT to one in five of its patients.

The firm, which sees roughly 4,000 women a month all seeking treatment for the menopause, is led by Dr Louise Newson, a GP and advocate of high-dose prescribing. 

She insists women may need double the licensed amount of oestrogen if they are struggling with mental health symptoms of the menopause, and that her approach is not risky.

However, following our article, the British Menopause Society (BMS), the Royal College of General Practitioners, the Royal College of Obstetricians and Gynaecologists and others all signed a joint alert, warning that oestrogen HRT should not be prescribed in doses higher than the licensed limits 'to ensure patient safety'.

Experts we spoke to say that until a few years ago they rarely, if ever, saw women taking such high HRT doses.

'We've all seen a huge rise in patients coming to us for cancer investigations,' said BMS chair Dr Paula Briggs, who is a consultant in reproductive and sexual health at Liverpool Women's NHS Foundation Trust.

'Most don't have cancer but it's really worrying for the woman and the tests aren't pleasant.'