“There are some cases where there isn’t the evidence that this is a beneficial treatment.”
Dr Michael Marsh, 1 September 2014
The parents of five-year-old brain tumour patient Ashya King are being detained after taking him to Spain against the wishes of his British doctors.
A Spanish court is considering an extradition request from Britain.
Hampshire Police got an international arrest warrant issued after Ashya’s parents Brett And Naghmeh took their son from Southampton General Hospital and travelled to Spain.
Ashya’s parents say they want their son to be given proton beam therapy to treat his medulloblastoma, a rare fast-growing brain tumour.
They say they disagree with doctors who have told them the treatment will not help Ashya.
For the first time today, Southampton General has defended the way it handled the case, with medical director Dr Michael Marsh saying: “We have discussed proton beam radiotherapy with Ashya’s family and there are some tumours that respond well to this type of treatment, but there are some cases where there isn’t the evidence that this is a beneficial treatment.
“Where the evidence supports this treatment, we have made a referral and patients have been treated abroad.”
What do we know about the effectiveness of proton beam treatment and why is it not available for most UK patients?
Proton beam therapy has been around since the 1950s. Conventional radiotherapy uses X-rays to zap cancer cells and stop them multiplying.
A stream of protons – the positively charged particles found in the nucleus of an atom – can be used to do the same job, and protons have the crucial advantage that they deliver less radiation to healthy tissue.
Due to a phenomenon known as the Bragg Peak, the stream of protons will stop at the tumour instead of carrying on moving through the rest of the body.
This has led fans of proton therapy to predict that patients who get the treatment will suffer from fewer complications and other medical conditions later on in life.
The technique is already on offer in the UK for patients with rare types of eye cancer at the Clatterbridge Cancer Centre in Merseyside.
Last year, the government announced it had earmarked £250m of funding for two new proton treatment centres at University College Hospital and The Christie in Manchester, which are due to be operational from 2018.
The news was greeted positively by doctors at those hospitals and charities like Cancer Research UK.
Others questioned whether the high cost of the project would deliver value for money. The Labour MP Grahame Morris has raised this several times, alleging on one occasion that private sector organisations had “lobbied incrediby hard” for the Department of Health to make the £250m spending commitment.
Richard Douglas, a senior civil servant at the Department of Health, told him: “I don’t think that any private sector body has been involved in the decision on the spending. I am not aware of the detailed lobbying that you described, but the decisions on spending are made by the department, the secretary of state and the Treasury, not by any private sector organisation.”
Some medical experts have questioned whether the available evidence actually proves that protons work better than X-rays.
There are few randomised trials – where patients are randomly assigned to different groups who get different treatments – on proton therapy.
In fact doctors have deliberately avoided doing randomised trials because they don’t think it would be ethical to deny a group of cancer sufferers access to a treatment they are already convinced is better.
High-profile critics of this approach include Fergus Macbeth, a cancer expert who helped developed guidelines on treating the disease for Nice, the independent body that advises the NHS on new medicines and treatments.
In a 2008 article, Dr Macbeth wrote: “Widespread introduction of proton therapy for an ever increasing range of indications would be folly without better evidence of effectiveness.”
Others critics have said that governments’ enthusiasm for high-tech proton treatment facilities tends to be based on flawed logic rather than hard evidence.
In 2009, the American Society of Radiation Oncology completed a review of the evidence, and the conclusions were mixed.
The researchers concluded that current data did not provide sufficient evidence to recommend proton beam therapy to treat cancers of the lung, head, neck and gastrointestinal tract, or any non-central nervous system cancer in children.
The study said there was no suggestion that proton therapy worked better than other types of radiotherapy in treating liver or prostate cancer.
It found that proton therapy did appear superior to earlier techniques in treating cancer of the central nervous system in children “but more data is needed”.
The society concluded cautiously: “(Proton beam therapy) is an important new technology in radiotherapy. Current evidence provides a limited indication…more robust prospective clinical trials are needed to determine the appropriate clinical setting.”
In Britain, a Cochrane Review – a gold-standard systematic review of all the available evidence on proton therapy – is underway right now.
Dr Marsh’s statement that “where the evidence supports this treatment, we have made a referral” is borne out by Department of Health figures.
British cancer patients are currently referred abroad (usually to clinics in America) for proton therapy if a panel of doctors decide they would benefit from it. The latest figures from the Department of Health were released in an answer to a parliamentary question:
Various cancer specialists have said in recent days that protons can be used to treat medulloblastoma, but it depends on the individual circumstances.
Oncologist Professor Karol Sikora said: “Brain tumour and spinal cord tumour in children is one of the prime benefits of this type of treatment but it is not for everyone, just a minority.”
If a tumour is too widespread, proton treatment would have no benefit, he added.
The only people who can say for sure that Ashya would benefit from proton therapy are those who have access to his case notes.
It’s impossible to second-guess the doctors without knowing more about the details of Ashya’s condition.
We know that doctors can and do recommend that patients are given proton beam therapy abroad – but doctors agree that not everyone will benefit from the treatment.
Some sceptics say evidence for the effectiveness of the technique is generally weak, despite the fact that it arouses strong emotions and attracts hundreds of millions of pounds worth of public money.