People with advanced cancer are using new technology to detect cancer recurrence or the mutation status of tumours. The three DYNAMIC trials are using liquid biopsies, blood tests that determine whether circulating tumour DNA (ctDNA) is present in the bloodstream. This new technology is also being explored in LIBERATE to detect the mutation status of tumours, which affects the treatments they can have.
In the DYNAMIC-III trial, people with bowel cancer are treated with surgery to remove their cancer. Then half of the patients will have a ctDNA blood test to determine their treatment. The other half will receive the current standard treatment.
People who have a positive ctDNA result, meaning that tumour DNA is present in the blood, will be treated with stronger chemotherapy than the standard treatment. People with a negative result will be treated with milder chemotherapy than the standard.
The trial is being led by Principal Investigators Associate Professor Jeanne Tie and Professor Peter Gibbs.
“Overall in terms of survival, screening will deliver the biggest impact,” says Professor Gibbs. “Ultimately if you can detect cancer that would not otherwise have been found in time then the patient may have the opportunity to go on to have curative surgery.”
DYNAMIC-Rectal is a trial investigating the presence of ctDNA for people with locally advanced rectal cancer, led by Associate Professor Jeanne Tie. People with locally advanced rectal cancer will have ctDNA tests to inform the decisions about their chemotherapy.
“We are hoping this helps avoid over-treatment of patients with unnecessary chemotherapy and identify those patients at high risk of recurrence who actually need chemotherapy treatment,” says Associate Professor Tie.
Pancreatic cancer is an aggressive form of gastro-intestinal cancer, with just 8.7% of people living for five years past their initial diagnosis.
After surgery for pancreatic cancer, liquid biopsies will be used to determine the presence or absence of ctDNA in the bloodstream. Surgery can cure pancreatic cancer, but the cancer often returns. Being able to determine the likelihood of recurrence will enable more effective treatments in the future.
Principal Investigator Dr Belinda Lee says, “I hope that ctDNA analysis will enable us to more accurately define recurrence risk and allow us to adjust treatment according to the individual patients’ risk of relapse.”
The study is testing the accuracy of liquid biopsies when compared to tumour tissue samples in determining the RAS mutation status of people with advanced bowel cancer.
The study is comparing different types of liquid biopsy technology.
“There have been a lot of changes in the technology to analyse liquid biopsies,” says Associate Professor Niall Tebbutt, Principal Investigator of the trial. “Some have pros and cons, and some are more expensive than others.”
This trial could improve the accuracy of test results for some patients.
“Some people have two primary tumours and when you’re doing the RAS test, it’s okay if the RAS mutation status is the same in both tumours, but if they’re different, we don’t actually know what the status is of that patient,” says A/Prof Tebbutt. “Perhaps in that situation blood testing would actually be better, because the blood is a reflection of the whole body.”
A person’s RAS mutation status can help to determine their treatment options. Liquid biopsies could help their treatment to be determined more quickly and with more accuracy, if they are proven to be effective.