MELBOURNE, Oct. 22 (Xinhua) -- A simple blood test detecting traces of tumor DNA could change how doctors decide which patients with colon cancer need chemotherapy, an Australian-led study finds.
The DYNAMIC-III clinical trial found testing for tiny fragments of cancer DNA in the bloodstream, known as circulating tumor DNA, or ctDNA, can reveal if cancer is present after surgery, and help tailor treatment accordingly, said a statement released Wednesday by Australia's Walter and Eliza Hall Institute of Medical Research (WEHI).
Published in Nature Medicine, the DYNAMIC-III trial involved more than 1,000 patients with stage 3 colon cancer from Australia, New Zealand and Canada, and had their blood taken about six weeks after surgery to remove their primary colon cancer.
Participants were then randomly assigned to receive either standard chemotherapy or treatment, guided by their ctDNA results, researchers said, adding that the findings show how ctDNA could bring true precision medicine to colon cancer.
"ctDNA is a powerful tool that can help guide treatment choices and identify which patients might safely receive less intensive treatment and those who might need to seek alternative options," said WEHI Professor Jeanne Tie.
"Right now, we give most stage 3 patients the same chemotherapy, but ctDNA testing can help tailor treatment based on individual risk," she said, adding that for some patients, a less intensive chemotherapy approach could be as effective while reducing side effects like oxaliplatin-induced toxicity and improving quality of life.
The study shows that a blood test can help give patients "more personalized, risk-adapted chemotherapy by identifying who may benefit from full-intensity chemotherapy and who can safely receive a reduced regimen," Tie said.
Those without detectable ctDNA had an 87-percent cancer-free survival rate after three years while receiving less chemotherapy and experiencing fewer side effects, researchers said, adding patients with detectable ctDNA after surgery faced higher recurrence risk, indicating a need for new treatments. ■
