New insights into how cancer spreads prompt rethink of metastasis care
A McGill University-led research collaboration has achieved a breakthrough in understanding how cancer spreads.
A clinical study of ovarian and colorectal cancer patients found cancer cells move in the bloodstream in clusters more commonly than was previously thought. The discovery could help doctors more quickly identify which cancer patients are at high risk of having their cancer spread to other organs, knowledge that could guide treatment decisions. The findings also potentially open new avenues for treatment.
The study, published in Communications Medicine, was conducted with researchers and clinicians Anne-Marie Mes-Masson and Dr. Diane Provencher at the Centre hospitalier de l’Université de Montréal, Dr. Peter Metrakos at the Research Institute of the McGill University Health Centre and Luke McCaffrey at the McGill-affiliated Rosalind and Morris Goodman Cancer Institute.
Cancer is responsible for about one-in-four deaths in Canada. In most cases, it is not the original tumour that proves fatal, but the cancer spreading to other organs, a process called metastasis. This occurs when circulating tumour cells (CTCs) break away from tumours, enter the bloodstream, and seed new tumours elsewhere in the body. On rare occasions, CTCs break away as a group of cells sticking to one another and forming a cluster.
“Our findings suggest these clusters may play an underappreciated role in metastasis. While clusters were recently found to be more effective at forming new tumours, they remained undetectable in most patients, and hence their contribution to disease dissemination was not considered,” said senior author David Juncker, Professor and Chair of McGill’s Department of Biomedical Engineering.
Breakthrough microfiltration method
The researchers made their discovery using a new microfiltration method they developed to capture cancer-cell clusters travelling through the bloodstream.
“We hypothesized that existing filtration methods might be breaking up the clusters during sample processing. So, we developed a gentler method to isolate these clusters from the blood without breaking them apart. Using this, we found many more CTC clusters than previously reported,” said Juncker.
The technology relies on an ultra-thin microfilter membrane – about one-fifth the thickness of a human hair – with tiny pores that trap cancer cells and cancer cell clusters while letting smaller blood cells pass through.
New treatment possibilities
The next phase of research will apply the new method as a diagnostic tool for detecting CTCs in colorectal cancer that has metastasized to the liver, one of the most difficult-to-treat forms of the disease.
CTC clusters could help stratify patients into low- and high-risk groups and help adjust the therapy accordingly. The researchers’ discovery could also open new avenues for treatment monitoring by tracking CTC clusters, and for developing new treatment strategies.
Mes-Masson added: “If clusters are key drivers of cancer spread, then breaking them up could help stop metastasis.”
About the study
“Gravity-based microfiltration reveals unexpected prevalence of circulating tumor cell clusters in ovarian and colorectal cancer” by Anne Meunier and David Juncker et al., was published in Communications Medicine.
The study was funded by the Canadian Institutes of Health Research, the National Science and Engineering Research Council of Canada and the Fonds de recherche du Québec.