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Blood tests are being used more frequently in the diagnosis of cancer. Santi Nuñez/Stocksy
  • Researchers say a new liquid biopsy blood test can help determine if a person needs chemotherapy after having colorectal cancer surgery.
  • They say the test could help some people avoid the negative side effects of chemotherapy.
  • The researchers also plan to study the test’s effectiveness with other types of cancer.

Liquid biopsies, the blood tests that can detect small pieces of DNA, RNA, or other molecules released by tumor cells, continue to show progress in cancer research.

Researchers have learned through years of study, for example, that these molecules can identify cancer at its early stages.

They can also reportedly identify new targets in the blood that can conceivably lead to new treatments.

These tests have also shown the ability to determine cancer staging and can help assess how aggressive the cancer regimen should be.

And they can evidently help oncologists decide what cancer treatments will work best as well as what treatments are not needed.

A new study from Japan published in the journal Nature Medicine details the ability of a liquid biopsy test called Singatera to identify people with stage 2 to 4 colorectal cancer who are at an increased risk of recurrence and are predicted to likely benefit from adjuvant chemotherapy.

Using this liquid biopsy test from Natera, a diagnostic and genetic testing company based in the United States, researchers determined whether or not those in the study needed chemotherapy after their surgery.

The protocol in treating colorectal cancer for years has been to surgically remove the cancer, then give the person additional chemotherapy.

But most of the time doctors can’t predict if this treatment will help.

The paper describes results from the GALAXY arm of the ongoing CIRCULATE-Japan trial, which is one of the largest and most comprehensive prospective studies of minimal residual disease (MRD) testing in resectable colorectal cancer.

In the study, 1,039 people with stage 2 to 4 resectable colorectal cancer were monitored prospectively using the Signatera MRD test.

In an interview with Healthline, Dr. Minetta Liu, the chief medical officer for oncology at Natera, said the findings from this study demonstrate the predictive and prognostic power of circulating tumor DNA testing in early-stage colorectal cancer.

“Signatera works by measuring tiny amounts of tumor DNA in the blood. GALAXY provides evidence to support its ability to reliably identify patients who are most likely to benefit from chemotherapy after surgery and those who may safely avoid additional treatment, potentially sparing thousands of individuals from the harmful side effects of chemotherapy,” Liu said.

“This is one of the most exciting developments to happen in oncology over the past year, and it will soon change the way oncologists treat patients with early-stage disease, ushering in a new era of personalized cancer management,” she added.

Liu said Natera plans to demonstrate Signatera’s clinical utility in multiple other tumor types with several peer-reviewed studies planned for publication this year.

Oncologists see this blood test as a new and effective way for people with colorectal cancer to avoid further chemotherapy for some people.

Dr. Michael Choi, a medical oncologist at UC San Diego Health who was not part of the study, told Healthline that he is impressed with the results.

“This is a legitimate use for this liquid biopsy,” Choi said. “It may still be a ways off for certain use. Specifically, these tests are not yet good enough to replace colonoscopy testing. But for this, I do believe this is a good and appropriate use.”

Meanwhile, the study’s principal investigator, Dr. Takayuki Yoshino of the National Cancer Center Hospital East, Kashiwa, Chiba, Japan said in a press release that “until now, oncologists did not have adequate tools to determine which colorectal cancer patients are likely to benefit from adjuvant systemic therapy.”

“This study provides strong evidence that Signatera MRD-positive patients will benefit significantly from adjuvant therapy, while MRD-negative patients may be safely observed, regardless of clinical or pathological stage,” he added.