Dr Parry Guildford, Professor of Biochemistry at the University of Otago is being funded by the National Science Challenge Healthier Lives – He Oranga Hauora to develop blood tests to detect DNA shed from cancerous tumours into the bloodstream.
Guildford, says the next step in his circulating tumour DNA (ctDNA) research is to trial using the simple blood test to help measure responses to chemotherapy or whether somebody’s cancer is still in remission.
Because Māori and rural cancer patients who live far away from a hospital with a CT scanner can face inequities – in getting their cancer treated and monitored – the trial is to first focus on working with Māori cancer and rural cancer patients, said Guildford.
More than 20 years ago Guildford and his research team worked with three Māori families to discover the gene that made the families’ young people susceptible to stomach cancer – including most recently Stan Walker.
Guildford said circulating tumour DNA (ctDNA) is being extensively researched worldwide but has been little used yet in New Zealand and he was keen for the new science to be trialled here first as a way of helping address inequities for vulnerable and remote populations. He has been working to adapt the technology to New Zealand conditions, develop ctDNA biomarkers for different types of cancer and make the diagnostic technology affordable.
By using biomarkers a simple blood test can detect whether a cancerous tumour is growing or shrinking by measuring whether the amount of ctDNA being shed by the tumour is increasing or decreasing.
Guildford said at present people starting chemotherapy treatment might have to wait 8-12 weeks and go through a number of fortnightly treatment cycles before having a CT scan or other monitoring to see whether the chemotherapy regime was making an impact on their tumour.
He said the vision of the ctDNA trial was that people had a simple fortnightly blood test that gave quicker feedback on whether their cancer treatment regime was working or whether other options should be pursued. For people living a distance from a hospital with a CT scan the blood test could also be an easier and cheaper way to monitor whether a person’s cancer was still controlled or in remission.
Guildford said using scans to monitor cancer had a number of limitations including only being available at the bigger hospitals which made it tougher for Māori who live in rural parts of the country. “That technology is also quite expensive, there’s a significant queue, and because of the radiation, you can only get them every eight to 10 weeks.”
Consultation with Māori is due to get underway shortly leading up to a trial probably next year, said Guildford. A second trial involving non-Māori patients living in rural communities was also to follow. He was also working on refining systems so blood samples could remain stable for up to two weeks so any transport problems from rural communities to urban laboratories are not an issue. “It means that sample can go on the bus from Ruatoria and if the bus breaks down along the way, it can still be used within two weeks.”
People interested in helping develop the technology are being encouraged to get into contact with Guildford who is the director of the University of Otago’s Cancer Genetics Laboratory.
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