Blood testing to monitor cancer

Professor Sarah Jane Dawson and Professor Mark Dawson

Photo credit: Peter MacCallum Cancer Centre

Associate Professor Sarah-Jane Dawson and Professor Mark Dawson

Peter MacCallum Cancer Centre | 2016 | $876,950

Finding cancer DNA in your blood is the latest test promising to be less invasive and more precise for enhancing treatment.

More than 12,000 Australians are diagnosed with blood cancers—such as leukaemia and lymphoma each year1—meaning monitoring and treatment decision-making is more important than ever.

Associate Professor Sarah-Jane Dawson, her husband Professor Mark Dawson and a team of clinicians are working together to develop a liquid biopsy—a simple blood test—as an alternative to invasive bone marrow or lymph node tissue biopsies to monitor blood cancers.

‘It was a natural transition where we thought we could combine our skills—using his clinical expertise in haematology and my experience in genomics to develop a liquid biopsy test in this area,’ said Associate Professor Dawson.

The team at the Peter MacCallum Cancer Centre, in Melbourne, Victoria are using more sophisticated and sensitive genomic technologies to measure tiny amounts of cancer DNA found in patients’ blood streams.

‘We have known for a long time that many cancers can shed small amounts of their DNA into the blood stream. This is called circulating tumour DNA,’ she said.

‘Measuring and then following this circulating tumour DNA can give us some understanding of how patients are responding or not to treatment.’

From a simple blood test they have been able to follow the changes of the cancer DNA and the amount of those changes overtime. A key advantage of the liquid biopsy is that it can be repeated frequently.

‘We are not going to replace the need for all tissue biopsies but if we could reduce the frequency of these tissue biopsies and gain real-time information about how the cancer is behaving from a simple blood test then that would be a very important thing to do,’ A/Professor Dawson added.

‘If we have earlier information telling us a patient is not responding to therapy then we can do something about it. We can hopefully make a positive change and switch them onto a therapy that may be more effective.

‘Often these tests can be turned around very quickly. If it’s a single mutation that is followed then it can be turned around within a few hours,’ she explained.

In comparison, patients need to be admitted and stay in hospital for over six hours for observation after a bone marrow biopsy.

‘These are not trivial procedures. They are invasive procedures—they are challenging and painful for patients,’ she said.

‘By replacing some of the tissue biopsy testing with a blood test we can better monitor the patient by being less invasive and less painful. Also from a health economic perspective there is a potential to save large sums of money.

‘Patients can really speak to the difficulties with tissue biopsies and how excited they are to potentially participate in something that means less invasive testing. It is also a very stressful and anxious waiting time,’ she explained.

Associate Professor Dawson has received an NHMRC Project Grant to investigate cancer DNA of chronic lymphocytic leukaemia—a type of blood cancer.

‘Unquestionably, the funding has allowed us to grow and explore the application of this testing across tumour streams,’ she said.

‘Without that funding we would never have been able to extend our testing to look at the range of different cancer types that we have.

‘I think one of the strengths about this test is that it is relevant across many different cancer types,’ she explained.

This type of NHMRC grant helps to create new knowledge by funding the best investigator-initiated research project plan between one and five years in any area relevant to human health.

‘I think we’ve progressed this field a long way but there is still a lot of work to be done to see the clinical application of this technology,’ A/Professor Dawson added.

‘We need to understand how to best use these tests, how often we should be doing testing in patients, and at what level do we change treatment decisions for patients based on circulating tumour DNA results.

‘There are still several questions to be answered in terms of how to immediately apply this technology in the clinic to improve our outcomes for patients with cancer. There is a lot of work to be done across many different tumour types.’

“Measuring and following this circulating tumour DNA can give us some understanding of how patients are responding or not to treatment”

1 AIHW (2012) Cancer in Australia