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
