World-first liquid biopsy for blood cancers

The more than 12,000 Australians diagnosed with blood cancers each year could soon have access to a simple blood test to monitor their disease thanks to a world-first ‘liquid biopsy’ developed by a veski innovation fellow at Peter MacCallum Cancer Centre.

The liquid biopsy for blood cancers developed by Associate Professor Sarah-Jane Dawson and veski innovation fellow Professor Mark Dawson, promises a new era of less invasive, more precise and effective management of blood cancers, in place of painful bone marrow or lymph node biopsies.

Published this month in both Nature Communications and Blood, the latest innovation from the Dawson Laboratories shows how liquid biopsies can be applied in clinical cases of chronic lymphocytic leukaemia and myelodysplastic syndromes.  

The test monitors tiny fragments of DNA emitted from cancer cells into the blood stream, called circulating tumour DNA (ctDNA). Unlike traditional biopsies, ctDNA tests track disease status throughout the body; can be used at any time over the course of cancer treatment; and enables rapid adjustments if a patient relapses or fails to respond to a particular therapy.

Associate Professor Sarah-Jane Dawson, who relocated to Australia with her husband in 2015, has helped pioneer the development of ctDNA tests for solid tumours in breast and other cancer types, which now guide the treatment of some 500 patients from across Victoria and Australia who are part of her research program at Peter Mac. 

She says this world-first ctDNA test for blood cancers will also help to more rapidly advance the availability of new precision medicines and targeted therapies as these are developed.

“Not only does this new test promise clinicians and patients a more timely and accurate understanding of whether a cancer treatment is working, it gives scientists the ability to quickly and effectively evaluate how clinical trial patients are responding to new life-saving therapies.

Professor Mark Dawson says the liquid biopsy also addresses one of the major limitations of the current approach to managing blood cancers.

“We know that a single tissue biopsy from the bone marrow or lymph node does not accurately reflect the composition of the whole tumour as there is significant variation – so called intra-tumour heterogeneity – that exists between the individual cells that make up any cancer.  

“Because cancer cells from all disease sites within the body shed their DNA into the bloodstream, we found that ctDNA collected from a routine blood sample more accurately mirrors the disease across all parts of the body. 

“This ctDNA test for blood cancer therefore provides a much more comprehensive picture of how a patient is responding to their treatment,” Professor Dawson said. 

The emergence of liquid biopsies as precision cancer trackers has the potential to significantly reduce costs to our health system. For example, Peter Mac currently conducts some 800+ bone marrow biopsies each year at around $2,500 per procedure, with patients undergoing the procedure required to stay in hospital for up to six hours each time.

Leukaemia Foundation’s General Manager, Research, Advocacy & Services, Caroline Turnour has reinforced the benefits of the liquid biopsy for the thousands of people living with blood cancers:

“This new test means patients will receive more personalised treatment rather than what historically is known to work for a disease but maybe not the individual,” she said. 

“This is a breakthrough that will contribute to less treatment-related toxicity and more patient-driven clinical care.”

The ctDNA tests from Peter Mac will be available to patients within Australia from late 2017 and are expected to become a standard clinical tool in the near future. Peter Mac will continue to develop its ctDNA expertise and technology so that the tests can be further refined and applied across more cancer types.

The ctDNA tests have been developed through collaboration across Peter Mac’s Pathology, Research and Clinical teams with initial and ongoing support from the Peter MacCallum Cancer Foundation and its supporters since 2013.