Urgent warning issued to cancer patients over dodgy 'cure' claims spreading online

England's top doctor has urged patients not to be fooled by "fairy tales" about quack cures, after experts warned of a boom in online misinformation. Medics at the world's largest cancer conference in Chicago said patients were turning down treatment and, in the worst cases, dying after pursuing dodgy alternative therapies.

Common myths that have spread like wildfire online include claims that juicing, following a ketogenic diet, taking mushroom , or positive thinking can cure the disease. Professor Sir Stephen Powis, England's medical director, said social media could provide a supportive community for those facing a diagnosis. But he warned: "At the same time we're also seeing an alarmingly high level of misinformation on some of these platforms.

"I would urge people to be sceptical of any 'miracle cures' you may see on social media around cancer, and use trusted, credible sources like the NHS website or your care team to verify anything you are unsure on - because these fairy tales aren't just misleading, they can be harmful."

Experts at the American Society for Clinical Oncology's (ASCO) annual conference in Chicago raised concerns that medics are "losing the battle for communication" online.

Dr Fumiko Chino, an oncologist at the University of MD Anderson Cancer, said the problem was fuelled by the pandemic, when there was "a proliferation of information available online".

She added: "We're losing the battle for communication. I think never more apparent right now is it obvious that evidence-based medicine has lost and we need to regain that battlefield."

ASCO chief medical officer Dr Julie Gralow said doctors were "feeling more than ever that we have to make the case for science and research and evidence".

She said of some patients: "They go online and search for something natural and they find a clinic in Mexico which promises an all natural treatment for cancer, which includes caffeine colonics, vitamin C infusions and other things."

In such cases, Dr Gralow said she lays out the evidence so patients can make an informed decision. Some who opt for an alternative approach return a few months later because they "didn't feel any better".

But she added: "A few times, they didn't come back. And then I would learn within nine months they tragically had died in some cases."

As well as social media sites such as , X and , Dr Gralow said AI search engine features - which scour the internet for answers to a user's query - were becoming a problem.

They allow people to "just type in questions and get answers spit out, and you wouldn't know where they came from", she explained.

Recent research by Macmillan Cancer Support found more than half of Brits believe misconceptions about cancer.

Richard Simcock, the charity's chief medical officer, said online misinformation had "exponentially increased the problem".

He added: "I have recently seen two young women who have declined all proven medical treatments for cancer and are instead pursuing unproven and radical diets, promoted on social media.

"A person is perfectly entitled to decline that therapy but when they do that on the basis of information which is frankly untrue or badly interpreted it makes me very sad."

Dr Liz O'Riordan is a retired UK surgeon and patient who shares content online to raise awareness and combat misinformation.

Speaking in Chicago, she said: "Every day I get messages from scared women who want to know if they need to stop eating dairy, soy, flaxseeds.

"Do they need to stop wearing underwired bras or using deodorants? Is it true that juicing can cure cancer? What about miracle supplement cures like mushrooms and CBD?

"There are celebrities pushing alternative or naturopathic beliefs - like cancer is our fault because we have negative emotions and toxic thoughts and that if our cancer comes back it's because we didn't have enough gratitude."

Earlier this year, Hollywood star Mel Gibson claimed on a podcast that three of his friends had overcome stage four cancer after taking ivermectin and fenbendazole. There is no scientific evidence the antiparasitic drugs are effective against cancer.

Dr O'Riordan was diagnosed with breast cancer aged 40 in 2015, and suffered recurrences in 2018 and 2023.

She said many doctors were "clueless about the vast amount of cancer misinformation online", adding: "I was, as a surgeon.

"I never went into that space. And then I got cancer and suddenly the algorithm changed and my eyes were opened.

"The more reels you click on, the more you're shown and suddenly it is easy to believe that soursop extract cures cancer and you need to detox daily."

Alternative medicine often portrays cancer doctors as "the bad guys, poisoning patients", Dr O'Riordan said. And it can be difficult for accurate information to gain traction online and be "heard above the noise".

She added: "What we're saying isn't sexy or exciting. We can't promise a cure. The drugs we give have side effects and some people still die.

"We need to get more doctors talking to patients on social media, explaining what cancer is and how it's treated, shouting from the rooftops about all the success rates and the latest developments in layman's friendly terms."