A team of researchers from Hospital del Mar in Barcelona has confirmed the utility of a liquid blood biopsy test for detecting colorectal cancer, with performance similar to current non-surgical detection options. The work, published in the journal Annals of Oncology, uses liquid biopsy technology to detect tumor markers in peripheral blood. The results showed that the test had a sensitivity of more than 90% in tumors and 23% in pre-tumor polyp lesions. The team believes the tool could be used to increase population participation in screening programmes, which now amounts to less than half of those invited to participate.
The study analyzed 623 blood samples, 318 of which were from people who underwent colonoscopy between 2017 and 2018 at Hospital Del Mar after the result of a fecal occult blood test, the test used in the colon cancer screening program, came back positive. The remainder were people diagnosed with colon cancer.
The test looks for DNA from a tumor in the colon, using different strategies each time. The test analyzes the presence of DNA mutations, methylations, or the presence of tumor-associated proteins.
“Multi-marker analysis makes it possible to increase sensitivity in detecting tumor DNA, which may be very sparsely present in blood samples in the early stages of the tumor,” explains Beatrice Bellosello, Head of the Department of Molecular Diagnostics. From the pathological autopsy service.
In this way, the liquid biopsy is developed “a step forward” from what is currently done, “turning it into a useful tool for detecting cancer at very early stages,” according to Joanna Vidal, the study’s author. He adds that it is about “looking for cancer before it shows its face.”
The work reveals that the blood test has similar sensitivity to the test used to screen the population in Catalonia, which relies on detecting traces of blood in stool. Both tests have high sensitivity, detecting more than 80% of cases, while their effectiveness for pre-neoplastic lesions and pre-neoplastic polyps is as low as one in four cases. Now a study is being conducted on thousands of people in the United States to confirm these results.
The authors of the paper believe that this new type of test would increase population participation in the colon cancer screening program. Currently, as indicated by Hospital del Mar, this program does not exceed 50% of the population invited to participate in Catalonia.
In this regard, Clara Montagut, Head of the Digestive Oncology Department at Del Mar Hospital, calls for participation in these programs, because early detection of tumors makes their treatment “easier” and increases the chances of recovery.
The study was conducted in cooperation with the US biotechnology company, Guardant Health, which is responsible for developing the test. The DEBI Biomedical and Imaging Network also participated, as well as researchers from the Cyber Cancer Center (Ciberonc).
Finally, Hospital Del Mar notes that colorectal cancer is most common in people over the age of 50. It represents 15% of diagnosed cancer cases in the state. It develops inside the large intestine from small lesions that can be removed before the tumor appears.
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