New treatment could save the sight of children with eye cancer

Times Online
Mark Henderson, Science Editor

Children with eye cancer are being offered a new treatment that could spare them the distressing side-effects of chemotherapy while improving the chances of saving their sight, The Times has learnt.

The procedure, which allows doctors to target tumours with toxic chemotherapy drugs while avoiding healthy tissues, has been given to 12 children with retinoblastoma at Great Ormond Street Hospital in London.

It involves passing a catheter through the patient’s blood vessels from an incision in the groin to the ophthalmic artery, which supplies the eye with blood. Chemotherapy drugs are then administered via the catheter.

As the drugs are infused directly into the eye, tiny doses can be used — as little as 5 per cent of the amount that would be given in standard chemotherapy — while still getting more to the site of the tumour than with conventional, body-wide treatment. Healthy tissues are not exposed to toxic drugs, avoiding serious side-effects such as sickness and nausea, hair loss and suppression of the immune system.

The entire procedure takes about an hour, with the child under a general anaesthetic.

Research in the United States has indicated that the technique, called intra-arterial chemotherapy, is at least as effective as standard treatments for retinoblastoma and may even lead to better outcomes.

As higher quantities of drugs reach the tumour than in ordinary chemotherapy fewer cycles of treatment are generally needed, which can raise the chances of saving a patient’s sight.

“This treatment gets the drugs directly to the place where they need to be soaked up,” said John Hungerford, a consultant ocular oncologist at St Bartholomew’s Hospital in London, who has pioneered its introduction to Britain. “It is proving to be a very good approach.”

Stefan Brew, a consultant neuroradiologist at Great Ormond Street, who inserts the catheters used in the procedure under X-ray guidance, said: “The advantage to doing it this way is that the drug is quite toxic and if you can deliver the entire dose to where the tumour is, you can get a high dose to the tumour and low dose to other tissues.

“The logic is to deliver the chemotherapy directly to the tumour in a targeted way, rather than the traditional blunderbuss approach.”

Retinoblastoma, a type of eye cancer that affects about 40 to 50 children — usually under the age of 3 — each year, is generally caused by a genetic mutation and can affect one or both eyes.

It usually responds well to treatment but is often diagnosed late. The main symptom is a white pupil that becomes visible only when the tumour fills one third of the eye.

Retinoblastoma is usually treated with systemic chemotherapy, in which the patient’s whole body is exposed to drugs so that some reach the eye. This causes severe side-effects and if it fails, the affected eye must sometimes be removed in a procedure called enucleation.

The intra-arterial approach was developed by teams led by Akihiro Kaneko, of the National Cancer Centre in Japan, and David Abramson, of Memorial Sloan-Kettering Cancer Centre in New York, to deliver a powerful chemotherapy drug called Melphalan directly to the tumour.

At present, it is used only when patients have already failed to respond to chemotherapy or when the cancer has returned and patients have already lost an eye to the disease. If chemosurgery continues to achieve good results, however, it could become a frontline treatment.

“All the children we have treated have responded well, though it is early days with some of them,” Dr Brew said. “At the moment it’s for children who have failed conventional treatment but what I’m hoping is that, as long as we can demonstrate that it is safe and effective, the next step would be to widen the criteria for use.”

Judith Kingston, a consultant paediatric oncologist at Great Ormond Street, said: “The biggest advantage is that the child doesn’t become systemically ill. He or she can have a normal life between treatments.”

The procedure is available on the NHS on a case-by-case basis, although only one of the children treated so far in Britain was an NHS patient. It costs £10,000-£15,000. Dr Kingston said that while this was more than standard treatment, there were savings on the follow-up care of patients suffering chemotherapy side-effects.

Libby Halford, the chief executive of the Childhood Eye Cancer Trust, said: “We are involved with the children and families affected by retinoblastoma right from diagnosis and all through their treatment and it can be extremely gruelling. The effects of chemotherapy can be very distressing.

“It’s important that new treatments such as this are in the armoury: to have it available in the UK is wonderful. You’ve been able to travel to the US, but the cost is huge and the families get immensely stressed. Losing both eyes is such a dreadful thing for parents to come to terms with when another treatment is available.”


Copyright 2009 Times Newspapers Ltd.