The message, from a stranger on Instagram, absolutely broke me. ‘Dear Liz,’ it began, ‘I need to tell you about a friend with advanced breast cancer. She has spent thousands on restrictive diets and supplements, instead of having surgery and chemotherapy.’

As a former breast surgeon who has had breast cancer three times, I’m used to people telling me about personal medical matters. I now write and speak regularly about the disease, trying to share evidence-based advice and help others navigate the minefield of misinformation online.

At the time of that Instagram message, I was researching The Cancer Roadmap, my book aimed at debunking myths about cancer treatment. I’d been discussing alternative therapies and the dangers of medical misinformation across my social media channels, so it wasn’t entirely a surprise to get a note like that. But as I kept reading, I felt a growing sense of dread.

The stranger wrote about her friend – let’s call her E – who found a breast lump just after her wedding day. She was frightened of chemotherapy and had refused all the treatment her doctors offered.

Instead she put her trust in an American herbalist who offers online consultations.

He instructed her to eat two kilograms (4.5lb) of raw fruit and vegetables a day and drink green tea, aloe vera juice and apple cider vinegar. She was told to buy a list of supplements: apricot kernels, turmeric, turkey tail mushroom, bitter melon and soursop.

Alongside this, she took off-label drugs: metformin, a diabetes medication, and ivermectin, the anti-parasitic ‘horse de-wormer’ falsely touted during the pandemic as a Covid cure. She was instructed to meditate, visualise herself healing and practise kindness to herself and others.

Within months, her cancer had spread to her liver and bones. She was in a wheelchair, in agonising pain, yet still clinging to the protocol. When tumours began to break through her skin, she added charcoal poultices, hoping they would ‘draw out toxins’.

Paloma Shemirani, daughter of former nurse Kate Shemirani, died from a heart attack linked to non-Hodgkin lymphoma aged 23 because she turned down chemotherapy – and, reportedly under her mother’s guidance, chose Gerson protocol instead

Only when it was far too late did she start palliative chemotherapy. She died weeks later.

By the end of the message, I was sobbing. A young woman was dead – not because there was no cure, but because she was persuaded to reject it. She believed lies dressed up as hope.

As a doctor, it makes me furious. But as a patient, I understand the fear that makes people turn to these false promises. I know how desperately you want control – to believe there’s a ‘natural’ path.

The problem is those peddling this kind of deadly bunkum prey on that desperation. They exploit it. It makes me shake with rage.

This all came flooding back when I was asked to appear in an episode of BBC One’s Panorama called Cancer Conspiracy Theories: Why Did Our Sister Die? The 30-minute show, which aired last week, brought us face to face with Kate Shemirani, a former nurse who lost her licence in 2021 for spreading dangerous theories during the pandemic.

It centred on the tragic story of her daughter, Paloma. Diagnosed in 2023 with non-Hodgkin lymphoma – a form of cancer with an 80 per cent survival rate when treated with standard care – Paloma turned down chemotherapy.

Instead, reportedly under her mother’s influence, she followed the Gerson protocol: daily juice cleanses, coffee enemas and supplements. It’s a scientifically discredited regime Shemirani has long promoted, claiming it cured her own breast cancer.

Paloma’s suffering and decline are painfully detailed in the show by her brothers Gabriel and Sebastian, who long ago severed ties with their mother due to her extreme beliefs.

In July 2024, Paloma, just 23, suffered a heart attack linked to her disease. She was put on life support but died days later.

Kate Shemirani has shifted the blame of her daughter’s death on to ‘medical interventions’, going so far as to claim on X: ‘Medicine is a lie… what we once believed to be healthcare is now a homicide service’

The brothers are now campaigning for stricter action against medical misinformation and awaiting an official inquest.

Sebastian told Panorama: ‘My sister passed away as a direct consequence of my mum’s actions and beliefs.’

Meanwhile, Kate Shemirani has shifted blame on to ‘medical interventions’, going so far as to claim on X: ‘Medicine is a lie… what we once believed to be healthcare is now a homicide service.’

The truth is, these kinds of horrific stories are becoming increasingly common.

E’s story sent me down a dark online rabbit hole of so-called ‘cancer coaches’ – a world I hadn’t realised existed. These practitioners don’t offer treatment themselves, but recommend alternative cancer therapists that do, as well as diets and supplements – for a fee, of course.

They want patients to ditch conventional treatment and use, among many other things, supplements and herbs, vitamin infusions, detox programmes, infrared and electromagnetic therapy and parasite cleanses.

They sell their services based on glowing testimonials and write persuasive books that promise miracles, thanks to protocols ‘your doctor won’t tell you about’.

And mainstream medics like me? We’re simply peddling drugs made by pharmaceutical companies hell-bent on profiting by keeping us unwell.

Of course I was aware of alternative cancer therapies – most cancer patients try something ‘natural’ even if it’s just lavender on a pillow to aid relaxation. But I had no idea of the industrial scale of it.

The global health coach market is estimated to be worth over £13 billion a year, which is expected to soar to more than £20 billion by 2032.

So I contacted cancer coaches using a pseudonym but my real medical history – and what I discovered was a sprawling, lucrative industry built on vulnerable hope.

Most aren’t medical doctors. Some are chiropractors or alternative therapists. Others have no health qualifications at all. But they all offer the same seductive promise: by uncovering the mysterious ‘root cause’ of my cancer – stress, trauma, toxins – I could heal myself without chemotherapy or surgery.

I’ve had breast cancer three times. It was hard even for me to accept that the standard medical treatment was the best way forward each time. As a doctor, I know cancer is sneaky – it can mutate and develop resistance to chemotherapy drugs. And the patient in me has felt at times like medicine failed me.

But I also know that without chemotherapy and radiotherapy I wouldn’t be here today.

Paloma’s brothers Gabriel and Sebastian spoke of their torment on BBC One’s Panorama in a documentary titled Cancer Conspiracy Theories: Why Did Our Sister Die?

When you hear ‘you have cancer,’ your world falls apart. You want hope. Control. Certainty you will survive.

No medical doctor can give you that. We aim to give the best that science has to offer, but there are no guarantees.

So I see how people are persuaded to spend thousands of pounds, re-mortgaging their houses, cashing-in pensions and crowd-funding in search of a cure. Some delay surgery. Others refuse chemotherapy.

I found a Facebook group for the families of those who consulted cancer coaches, went to foreign clinics, and died.

Just like E, they trusted the wrong person. It’s grim reading. You don’t see these testimonials on the flashy cancer coach websites.

The problem is, there is little regulation. Anyone can call themselves a cancer coach. There are no legal standards. No licensing body. No complaints process.

Shortly after getting the message about E, another woman got in touch to tell me about her friend – who we’ll call W.

He had advanced bowel cancer and was having chemotherapy, but was terrified of dying so consulted a cancer coach overseas he had found online, who told W: ‘Nobody has ever died on my watch.’

W began a restrictive diet of mainly fruit and vegetables, with no dairy, as well as a cocktail of herbs and supplements, including sea moss.

He was told to rent a bioresonance machine at £1,000 a month to use for several hours a day. The theory is that it would manipulate energy waves emitted by cancer cells to help them vibrate at a healthy frequency. There is no evidence it works.

W’s cancer grew. The coach told him to double the time he spent using the machine and order more supplements.

W ended up in a hospice. His team took one look at the supplements and were horrified. The sea moss was damaging his liver and others interfered with chemo drugs.

The diet left his body less able to cope with treatment. W was switched to palliative care and died a few weeks later. It’s impossible to know whether the coach’s recommendations sped up his death. His website is filled with glowing testimonials.

This isn’t fringe wellness any more. It’s a booming, unregulated industry worth billions – fuelled by fear, slick marketing and pseudoscience.

And its victims? They’re often too ill to challenge it, too ashamed to speak out – or no longer here to tell their story.

The Cancer Roadmap: Real Science To Guide Your Treatment Path, by Dr Liz O’Riordan (HarperCollins), is out now.