Patients with inoperable head and neck cancer have seen their tumours “drop off” after treatment with a new form of laser therapy, doctors say.
The technique involves no surgery, can be carried out in a few minutes and does not harm healthy cells.
Doctors at University College Hospital in London have tested the latest form of photodynamic therapy on 11 patients with advanced head and neck cancers, all of whose tumours have shrunk or died away.
Although initial trials aimed to test only the safety of a new drug, which makes cancer cells sensitive to light and boosts the effects of chemotherapy, early results are so impressive that they have been submitted to a leading journal for publication this year.
Colin Hopper, a head and neck surgeon at the hospital, is leading the study. He said that patients with advanced or recurring cancers who had stopped responding to chemotherapy had experienced benefits.
One patient with an inoperable tumour on his tongue saw it disappear completely, while another, with advanced sarcoma on his jaw, lived for six months, far longer than doctors predicted.
Mr Hopper said: “This was a phase-one, dose-escalation study — you don’t normally expect the first patients to have a response, but with the first person we treated the tumour turned black and then dropped off, there was a quick clinical response in the targeted area. That’s been consistent in the 11 patients we have treated.”
During photodynamic therapy a drug is injected into the patient’s bloodstream that makes the cancer cells extremely sensitive to light. Those involved in the trial were injected with a new drug — known as Amphinex, a photosensitising agent — three to four days before being given standard chemotherapy. Because tumours have high metabolic activity and are surrounded by a proliferation of new blood vessels, the drug accumulates in cancer cells in preference to healthy tissue. When a low-powered red laser is shone on the tumour, directly or through the skin, the light triggers a chemical reaction that disrupts the harmful cells and boosts the action of a chemotherapy drug, bleomycin. “The results are quite impressive,” Mr Hopper said. “You can see the tumour turn black and die, not quite before your eyes, but over a matter of days.”
Although one patient died during the trial, this was not related to the therapy. No other serious side-effects have been reported.
If further trials are successful, Amphinex, made by the Norwegian company PCI Biotech, could be available on the NHS within five years.
Although the National Institute for Health and Clinical Excellence recommended photodynamic therapy as a treatment for head and neck cancer more than six years ago, it is still under-used and more commonly available to patients with skin cancer.
Out of 8,000 head and neck patients treated in 2008, only 180 received the therapy, nearly all at University College Hospital. The Department of Health commissioned a review of photodynamic therapy in 2007, but it is not expected to be published until this year.
Lesley Walker, of Cancer Research UK, said: “It is a promising treatment option which may be very useful for helping to treat some cancers, but it is unlikely that photodynamic therapy would ever be suitable for treating all types of cancer.”
