A test designed in
Dunedin which could lead to more effective treatment for some
bowel cancer cases worldwide is about to be granted a New
Zealand patent.
The test, which should be through clinical trials in New Zealand and Germany early next year, is being developed by Dunedin biotechnology company Pacific Edge Biotechnology.
Company chief scientific officer Associate Prof Parry Guilford said by studying the genes in samples of grade two tumours (where the cancer had not been found beyond the bowel wall, in lymph nodes or other areas of the body), a test had been developed which could help determine which cancers were likely to progress.
About 20% of people treated for cancer at the stage 2 level would have the cancer reappearing within five years, with it eventually spreading to the liver.
In New Zealand, there were about 2500 new cases of colorectal cancer annually, with about 875 of them being found to have the cancer at stage 2.
Generally, patients at stage 2 were treated with surgery and not offered adjuvant chemotherapy, designed to kill off any cancer cells which could be lurking.
Prof Guilford said chemotherapy was offered once the cancer had spread to stage 3.
At this stage, lymph nodes are affected, but not other parts of the body.
The prognosis test was expected to be able to determine, in about 85% of cases, which cancers would progress and which were unlikely to.
This meant patients would not undergo unnecessary treatment and those patients considered at higher risk could be treated earlier, making their treatment more effective.
The test would involve sending a sample of a removed tumour to the laboratory, so it could be checked for presence or absence of the gene signature which would predict a relapse.
Early development of the test involved looking at the genes from frozen tumour samples gathered in New Zealand by surgeon John McCall, who "had the vision" to do this some years ago.
Other samples were also provided from Germany, where the company has been collaborating with the University of Munich.
Pacific Edge chief executive Dr David Darling said the cost of the test had not yet been established, but a similar prognostic test for breast cancer recurrence used in the United States cost $3650.
While this might seem expensive, it could avoid the spending of thousands of dollars on more surgery and would allow chemotherapy treatment to be used when it might be most effective.
Pacific Edge's first product, an early diagnostic and monitoring test for bladder cancer, which uses a urine test, is expected to go on sale early next year in New Zealand and Australia, following the completion of clinical trials in both countries and Russia.
Dr Darling said the test was expected to cost around $300, compared with the cost of up to $980 for a cystoscopy .
With an expected accuracy of about 85% to 90%, a negative test could mean many patients would avoid an invasive cystoscopy.
The test could also be used by clinicians as a surveillance measure for their patients, over time, who might be tested every three to six months.
Cystoscopy is a test used to examine the bladder by inserting a tube through the urethra.
elspeth.mclean@odt.co.nz