MELBOURNE researchers have developed a “liquid biopsy” to more quickly and accurately gauge whether malignant tumours are shrinking.

The simple new test analysing cancer tumour DNA in the blood would replace invasive tissue biopsies.

Peter MacCallum Cancer Centre clinician researcher Dr Sarah-Jane Dawson said looking for this circulating tumour DNA in blood had been like “looking for the needle in the haystack”. But new-generation genetic sequencing allows a complete snapshot of the cancer to be captured as it evolves.

“As the cancer cells turn over they release their DNA into the bloodstream,” Dr Dawson said. “While we’ve known this for some time, it’s only been recently with advances in genomic technologies that we now have sensitive techniques that allow us to very precisely identify this small fraction of tumour DNA in the blood.

“We think this is a really exciting development and it does hold a lot of promise for making a big difference to the management of cancer patients.”

Dr Dawson came to Peter Mac in March from the University of Cambridge, where she was involved in a landmark study that showed levels of tumour DNA in the blood of breast cancer patients reflected whether those women were responding to treatment.

A clinical trial testing the liquid biopsy in Victorian breast cancer patients is due to begin next year. “In an ideal world, we would take regular biopsies during someone’s treatment. But often that’s not feasible, and it’s invasive,” Dr Dawson said.

“We know cancers evolve and become resistant to treatment over time,” she said.

“By repeating these blood tests regularly, they may give us a very accurate understanding of whether someone is responding to their treatment or not — which is very important for a woman to understand.

“She doesn’t want to be on a treatment that’s not working, or be exposed unnecessarily to side-effects, when she could be switched to a therapy that could be more effective,” Dr Dawson said.

“The hope is we can get that information quicker and more accurately than we can now.”

Story source: Herald Sun