A new blood test that targets tumour DNA in people with colorectal cancer is shaping up to be a game changer when it comes to early detection of disease recurrence.

Flinders University researchers have developed a ‘two gene’ test that picks up early recurrence at twice the rate of the standard test currently used.

The authors, including Professor Graeme Young, Professor of Global Gastrointestinal Health at the university and Chairman of the Governing Council (board) of the Flinders Centre for Innovation in Cancer, and senior researcher Dr Erin Symonds, will present their findings at the Australian Gastroenterology Week Conference in Adelaide this week.

Speaking to the limbic on the eve of the conference, Professor Young said the new test had the potential to fill an urgent and unmet clinical need and save more lives and surpass the efficacy of the current carcinoembryonic antigens (CEA) monitoring regime.

“It’s been really important to get a better test and especially one that is capable of detecting tumour-derived DNA,” he said.

“This is potentially very exciting.”

The test found methylated BCAT1 and IKZF1 DNA in blood in almost 70% of patients with recurrence, while only 32.1% tested positive for CEA, a common test offered to colorectal cancer patients who have undergone surgery.

Professor Young said the study findings would be published in the journal Cancer Medicine later this month.

“Given that 40% or more of patients in remission from CRC following initial treatment will develop recurrence, improved surveillance methods that accurately detect recurrence are essential for improving outcomes for patients,” Professor Young said.

“Data from this study reinforce previous findings that circulating tumour-derived DNA can be reliably detected in CRC patients with recurrence.

Furthermore, the results suggest that when used in ongoing surveillance of cases in remission, a positive BCAT1/IKZF1 test has the potential to establish a new approach for earlier detection of recurrent CRC by detecting more unsuspected recurrences and triggering earlier imaging studies.”

More studies are currently underway to move the test closer to being commercially available. Professor Young said he expected this would take between one and two years, however he was quietly confident it could ultimately replace the CEA test in the clinical guidelines.

“There doesn’t seem to be any downside to this test,” he said. “I think it’s reasonable to say that’s our hope (having it replace the CEA test).”

A role in colorectal cancer screening

Professor Young said there might also be a use for the test in colorectal cancer screening, and in detecting other cancers.

When diagnosed early, before cancer has spread, the relative five-year survival rate for CRC is 90%, but only approximately four out of 10 CRC cases are detected early, making this new test a potential game changer for survival odds.

Among individuals undergoing surgical treatment for CRC, recurrence occurs in 30 to 40% of all cases, the majority of which present in the first two to three years following initial diagnosis and treatment.

This study compared the sensitivity and specificity of the two-gene blood test for tumour-derived methylated BCAT1 and IKZF1 with those of CEA in patients undergoing surveillance for recurrent CRC following induction of remission.

“We believe the two-gene test has the potential to fill an urgent and unmet clinical need, and are committed to advancing its clinical development as a new tool for improving patient outcomes,” Professor Young said.

Professor Young is the Convenor of the Colorectal Cancer Screening Symposium, Australia’s first multi-disciplinary symposium on colorectal cancer screening, mooted as a highlight of this year’s Australian Gastroenterological Week Conference.

ABC journalist and broadcaster, Richard Aedy, will facilitate the symposium on Monday, October 10, from 6.30-7.30pm.

Panellists will include Professor Young AM, and the University of Melbourne’s Associate Professor Alex Boussioutas and Professor Finlay Macrae.

Experts from all over the world are expected to attend the conference, organised by the Gastroenterological Society of Australia (GESA).