Cancer treatment just took a new turn. A blood test being trialled at hospitals in Australia and New Zealand to detect cancer cells in the body after surgery could transform follow-up treatment.
Once a tumour is removed, many patients are advised to undergo chemotherapy to ensure all cancerous cells have been removed. Until now.
Associate Professor Jeanne Tie, from the Walter and Eliza Hall Institute (WEHI) which is overseeing the Australian trial, explained that when cancer cells rupture and die, they release their contents, including cancer-specific DNA. If these cells are detected after surgery, it indicates there are still microscopic cancer cells in the patient.
If these cells are detected after surgery, the patient has close to a 100 per cent chance of the cancer returning; a negative test indicates less than a 10 per cent chance of a relapse, she said in a report for The Conversation.
The test was developed through a collaboration between the WEHI and Johns Hopkins Kimmel Cancer Centre in the US. More than 400 patients have joined in the trials, and Assoc. Prof. Tie says she hopes this will grow to more than 2000. The trials are expected to run until 2021 for bowel cancer and 2019 for ovarian cancer.
The same blood test is also helping to determine the dose for patients who need chemotherapy.
“Chemotherapy comes with a host of serious side-effects,” says Assoc. Prof. Tie. “Short-term, these include pain, fatigue, nausea and other digestive issues, bleeding problems and an increased susceptibility to infection. Long-term side-effects may include heart, lung, nerve and memory problems, and fertility issues.
“If you look at the literature, there are always deaths in treatment. It’s very low but when it has happened to your patient you’re really scarred.”
She said the decision as to whether to use chemotherapy for a bowel cancer patient had been based on a laboratory assessment of the cancer removed during surgery. “For example, if there are cancer cells in the lymph glands next to the bowel (a stage 3 cancer), there is an increased probability the cancer has already spread elsewhere,” she said.
For such cancers as ovarian and pancreatic, other methods determine whether chemotherapy is necessary. But they all lack precision, said Assoc. Prof. Tie. “Ultimately, some high-risk patients will not have cancer recurrence because their cancer has been cured by surgery alone, while other apparently low-risk patients will suffer from recurrence.”
In a case study reported in Fairfax Media, Hugh McDermott, a medical bionics professor who had surgery for bowel cancer, was able to avoid months of chemotherapy after a negative blood test indicated he was at low risk of his cancer returning.
“What I was very surprised about is I couldn’t get any clear and definite advice about whether chemotherapy would be likely to help me or not,” Professor McDermott told The Age.
As a result, he enrolled in the trial, received a negative test and has been recovering well, The Age reports.
Would you consider joining the trial? Have you ever participated in a medical trial?