Could a simple blood test tell you if your cancer will spread? CCS-funded researcher Dr Shana Kelley is developing a new blood test for cancer and recently published a new way to find and study cancer cells in the blood.
Cancer cells can be found in blood
Cancer is much easier to treat when it is discovered early, before it has had a chance to spread to other sites in the body. To catch cancers sooner, we need to develop new tests to diagnose and monitor the disease.
Researchers are studying whether liquid biopsies, or blood tests, could be simple, non-invasive alternatives to traditional tests for cancer. These blood tests look for cells in the bloodstream that have been released from cancerous tumours. These cells are called circulating tumour cells (CTCs). CTCs provide a telltale sign that cancer is present, and they could even be the cause of cancer spread (metastasis).
The challenge of using CTCs to study cancer is that they are very rare in the bloodstream. In fact, normal cells outnumber cancer cells 1 billion to 1 – it is like finding a needle in a haystack!
Blood test detects cancer cells
Previous technologies have only been able to count CTCs in the blood without considering any of their individual properties. Much like the cancer cells in tumours, CTCs have different properties that make them more or less aggressive and determine whether or not they will be able to spread in the body and form new tumours.
Dr Kelley and her team at the University of Toronto, developed a new technology that isolates and counts CTCs, as well as determines their individual features, or markers.
They were able to capture CTCs from blood samples using magnetic nanoparticles – 1,000 times smaller than a red blood cell – that bind specifically to protein markers on the surface of CTCs. They also grouped the CTCs depending on how much of the protein marker was on the cell surface. They are now trying to use these groups of cells to figure out how likely these tumour cells are to spread and grow in the body.
Blood test will help guide cancer treatment
The researchers developed this new method by using both mouse models of cancer and studying blood samples collected from prostate cancer patients, with both approaches showing that the technology could play an important role in the clinic.
Researchers will be able to use liquid biopsies to find and study CTCs to uncover new ways to diagnose and treat cancer as well as monitor disease progression and predict the aggressiveness of a cancer. All of this information will help cancer biologists and doctors understand how to use these cells to better treat patients.
Katherine Wright, PhD