People with colorectal cancer, the fourth most common cancer in the US, are often given unnecessary chemotherapy long after the cancer is in complete remission.
There is hope that some patients may be saved once clinical trials of the high-tech treatments are finished and evaluated in a few years.
For decades, doctors removed people’s colorectal tumors and decided whether their patients needed further chemotherapy by considering various risk factors. This method was not precise, and sometimes people who did not need chemotherapy received it anyway.
Now there is a possibility to move forward. New genetic sequencing technology can detect previously undetectable levels of cancer with just a single blood draw. If a patient does not have cancer DNA, he may not need chemotherapy after surgery, new research from Australia has suggested.
“What we did know was that many of these patients were cured with surgery alone. We have no way of knowing,” said Dr. Mohammadtaqi Tejani, MD, medical oncologist and director of the Gastrointestinal Oncology Program at AdventHealth Cancer Institute and AdventHealth Research Institute. Who had microscopic cancer in their blood, who needed chemotherapy and who didn’t.”
In 2019, 10,496 Floridians were diagnosed with colorectal cancer, according to the Centers for Disease Control and Prevention. That number is likely to be inflated by people delaying colonoscopies during the pandemic.
Many end up getting chemotherapy, which uses powerful chemicals to kill cancer cells and costs thousands of dollars with insurance. The out-of-pocket cost for the insured can reach six figures. Normal, healthy cells often die even with treatment, and while they can recover, their absence causes symptoms such as nausea and vomiting, hair loss, tiredness, and fever.
According to the Mayo Clinic, infertility, lung disease, other cancers, heart problems, hearing loss, nerve damage, memory problems or early menopause may show up years after treatment ends.
Tejani directs the AdventHealth site to two National Cancer Institute clinical trials of this sequencing technology, called SIGNATERA, developed by DNA testing company Natera.
One clinical trial involved patients with stage III colon cancer, which is when the disease has spread to the tissue surrounding the lymph nodes.
Traditionally, these patients are given chemotherapy followed by surgery, although by some estimates, about 50% of stage III colon cancer patients are cured with surgery alone.
Tejani said the study will randomize chemotherapy on or off to stage III patients who test negative for circulating tumor DNA, and then follow their long-term outcomes. It started in March 2022 and will end around March 2030. Tejani’s AdventHealth site is currently enrolling participants.
Another clinical trial of phase IIA colon cancer patients is underway since 2019 and is targeted to end in 2027.
However, some researchers have reservations.
In a study by Canadian medical professionals published in May, they called the “Holy Grail” the potential applications of this technology for detecting hereditary cancer. But he was also concerned about the implications of false negative tests.
One unnamed medical professional said this could prompt patients to delay getting routine screening tests.
Several doctors, whose identities have been redacted, said in the survey that they were also concerned about how a positive result might affect a patient’s mental health.
“If you don’t do anything about what you’re already doing, you’ll just be a worried patient,” wrote one anonymous doctor.
To critics, Tejani points to another study involving AdventHealth that will track the blood test’s impact on patients’ quality of life, done by the company that makes it. Its expiry date is 2025.
In the future, Tejani hopes the test could also be used to detect signs of colon cancer in people who haven’t yet been diagnosed, and to screen for other types of cancer, such as gynecological or pancreatic. .
Tejani said, “I think there will come a day when we will all be tested and we will be able to see if we are prone to a particular type of cancer in our lifetime.” “Unfortunately, I meet people who already have it and try to help them live as long as possible.”