Radioactive microspheres delivered directly to tumours in the liver offer new hope to those failed by conventional treatments.
A radical bowel cancer treatment that injects tiny glass bullets into liver tumours could cure those with no other hope, research suggests.
Doctors injected microscopic glass balls smaller than a speck of dust to target disease. Experts said they were excited by “very impressive” findings, including cases in which patients were effectively cured.
Bowel cancer is the fourth most common form of cancer in Britain, with the vast majority of deaths occurring when the cancer spreads to the liver and becomes inoperable.
The new findings, from the world’s largest interventional radiology cancer trial, tracked 530 patients who had reached this stage.
Half were injected with the microscopic radiotherapy, on top of the standard drug treatment given to all those in the trial.
In total, those given the pioneering treatment saw progression of liver tumours stall for 20.5 months, when the drugs alone secured just 12.6 months, the six-year study found.
Researchers said the findings, presented at the American Society of Clinical Oncology’s annual conference in Chicago, were “very encouraging” and could offer new hope to those failed by conventional treatment.
Some of those given the one-off treatment – which costs about £14,000 ($27,000) and takes just a few hours – had now lived for more than five years, with no trace of their tumours, researchers said. One of the first patients to receive the experimental treatment remained disease-free 13 years on, the study’s principal investigator said.
The microscopic glass balls used in the radiation therapy contain the radioactive isotope yttrium-90. The “bullets” are delivered directly into blood vessels in liver tumours, using a flexible catheter inserted via the groin.
Because the treatment is targeted directly into tumours, damage to surrounding healthy tissue can be limited, reducing the levels of side-effects. After one session, the microspheres continue to generate radiation for weeks after the treatment.
Dr Peter Gibbs, the study’s co-principal investigator, from The Royal Melbourne Hospital, Australia, said: “This is a very impressive result; it’s very encouraging.”
The cancer specialist said the study had shown that tumours entirely disappeared, for more than five years, after a session of treatment.
“One of the very interesting results is an increase in ‘complete responses’ – when tumours disappear,” he said. “Normally, you see that in about 1 per cent of chemotherapy cases. There was a higher incidence of that in this trial – around 5 per cent, and in about half of those cases the tumours didn’t regrow; treatment seemed to be curative.”
Dr Gibbs said one of the patients he treated as part of the trial – a man in his seventies – remained free of cancer, five and a half years later.
“We are quite optimistic, quite excited,” he said. “When you have a patient and it has been five years with no trace of the tumours, I would say they are cured.”
Dr Gibbs said one of his first patients to be given the experimental treatment, back in 2002, before the major trial, remained free of disease after 13 years.
Each year, about 41,600 people in Britain are diagnosed with bowel cancer, which causes more than 16,000 deaths annually. The new study found the targeted treatment did not significantly slow progression of tumours elsewhere in the body.
However, researchers said the findings with regard to liver disease were crucial, given the vast majority of bowel cancer deaths stemmed from tumours in this organ.
Mark Flannagan, chief executive of the charity Beating Bowel Cancer, said: “Any treatment that can stop liver tumours progressing for longer could give patients more precious time to spend with their loved ones.
“We are encouraged by the results of the study, which suggests possible tumour shrinkage as well as delays in regrowth. This could also maintain good quality of life for bowel cancer patients for a longer period.”
Andrew Langford, chief executive of the British Liver Trust, said: “The liver is the most common part of the body for bowel cancer to spread to, and once it’s there, the outlook for the patient is poor. The study shows real promise.”
About 10,000 of the 16,000 bowel cancer deaths in Britain each year are associated with liver failure.
Dr Harpreet Wasan, consultant oncologist at Imperial College Healthcare trust, said the new findings were better than he had hoped. “We expected four to six months, but it turned out to be an extra eight months of progression-free survival in the liver.”
CASE STUDY:
‘I’m back to my normal self’
Brian Brooks, 75, from Ely in Cambridgeshire, received the radical treatment in 2010 after cancer spread from his bowel to his liver.
Doctors had said the tumours were inoperable and he probably had less than a year to live.
However, the retired dog kennel owner heard about clinical trials for a new targeted treatment. The tumour in his liver was destroyed and doctors successfully operated on the disease in his bowel. Five years on, the pensioner remains disease-free and enjoys gardening and golf.
“I was last scanned three months ago and I’m all clear, and that’s five years on. I’m totally back to my normal self,” he said.
He added that the results of the treatment felt like a miracle.
“Life’s begun again,” he said.
The Telegraph, London