A new cancer treatment which sees tiny radioactive balls fired at tumours dramatically hinders their growth, according to new research.
Use of the “resin microspheres” alongside chemotherapy on patients with bowel cancer that has spread to the liver was shown to halt the growth of liver tumours for almost eight months longer than chemo alone, the study found.
In 6% of cases it sent the cancer into remission, three times more frequently than using chemotherapy alone, the research discovered.
Each year around 41,600 people in the UK are diagnosed with bowel or colorectal cancer, which includes cancer of the colon and rectum, and 16,200 die from the disease. In about 60% to 70% of cases, the cancer spreads or “metastasises” to the liver.
The findings were presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago by associate professor Peter Gibbs.
Prof Gibbs, co-principal investigator and consultant medical oncologist at The Royal Melbourne Hospital in Australia, said: “This finding matters a great deal because the liver is almost invariably the organ where colorectal cancer spreads to first.
“While half the patients initially diagnosed with colorectal cancer survive thanks to surgical removal of the primary tumour before the disease has spread elsewhere in the body, liver metastases eventually cause the death of the majority of the remaining hundreds of thousands of patients each year whose tumours spread but are inoperable.”
The study, called Sirflox, examined the effectiveness of what is known as selective internal radiation therapy (SIRT) or “radioembolisation”.
It studied the effect on 530 people of using resin microspheres made by Australian firm Sirtex Technology Pty Ltd, which sponsored the research.
It found that using the radiation treatment with chemotherapy increased the median halt in tumour growth from 12.6 months to 20.5 months, an increase of almost eight months.
The microspheres used are about a third of the width of a human hair and contain the radioactive isotope yttrium-90. They are delivered via a catheter directly in to cancer-affected parts of the liver through the tumours’ own networks of blood vessels.
They then become permanently lodged in the small blood vessels surrounding a tumour and starve it while having a minimal impact on surrounding healthy tissue.
They continue to generate radiation for weeks after treatment.
The therapy is already approved in the European Union for treating certain types of liver cancer.
Sirflox is one of three trials of the technology in progress. A second was launched last month by Oxford University.