Canadian researchers are exploring a liquid biopsy test that could lead to early diagnosis of malignant mesothelioma.
The test is based on mesothelial precursor cells (MPC). The researchers say these cells – in combination with mesothelin and some kinds of stem cells – “could be implicated” in the development of mesothelioma.
A liquid biopsy detects cells in blood instead of tissue. The University of Toronto scientists think MPC in blood may be a new mesothelioma biomarker. If it proves to be true, this kind of biopsy might be able to identify mesothelioma patients even before they have symptoms.
How Liquid Biopsy Works
Patients with suspected mesothelioma may have many tests. Imaging scans and blood tests can help tell if a biopsy is warranted. Right now, tissue biopsy is the only way to know for sure if a person has mesothelioma.
Most people associate the word “biopsy” with removing some tissue. But a biopsy is just a procedure to take a sample of cells from the body. If those cells are in the blood, it is a liquid biopsy.
Liquid biopsy has some advantages over tissue biopsy for patients. It is less invasive, less expensive, and less painful. It also produces faster results. Because a blood test is easy to repeat, doctors can use it to tell if a treatment is working.
There is no diagnostic blood test for mesothelioma. But the new Canadian research could change that.
A Blood Test for Early Mesothelioma?
It is rare to find MPC in the blood. Most conventional blood tests cannot find these cells. That is why the Canadian researchers developed their own liquid biopsy for mesothelioma. They call it MesoFind.
“MesoFind…utilizes an immunomagnetic, mesothelin capture strategy coupled with immunofluorescence to identify rare populations of cells at high sensitivity and precision,” they write.
They tested MesoFind on 23 pleural mesothelioma patients, 23 asbestos-exposed people, and 10 healthy people. The goal was to see how well the test picked up diagnostic and prognostic markers.
The new liquid biopsy showed MPC were higher in people with mesothelioma than in healthy people. Two other markers (mesothelin and CD90+ stem cells) were high in asbestos-exposed people. People with advanced mesothelioma had high mesothelin and CD34+ stem cells. The results suggest that MesoFind could be useful for mesothelioma diagnosis and prognosis.
“The identification of circulating MPC presents an attractive solution for screening and early diagnosis of epithelioid mesothelioma,” writes University of Toronto researcher Bill Duong. “The presence of different subtypes of MPC have a prognostic value that could be of assistance with clinical decisions in patients with MPM.”
Duong, B, et al, “A liquid biopsy for detecting circulating mesothelial precursor cells: A new biomarker for diagnosis and prognosis in mesothelioma”, October 9, 2020, EBioMedicine, Epub ahead of print, https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(20)30407-2/fulltext