A new blood test for detecting pancreatic cancer has been shown to have an accuracy rate of more than 90 per cent in identifying early-stage cancers. The news is a potential game changer for a disease that until now has been very difficult to detect in its early stages, resulting in a very low survival rate.
Often called the “silent killer,” cancer of the pancreas — the large gland in the upper part of the abdomen that produces digestive juices — is a deadly disease, in large part because it is both an aggressive form of cancer and typically not detected until already at an advanced stage. According to the Canadian Cancer Society, the five-year net survival rate for pancreatic cancer is a dismal eight per cent.
Early detection of pancreatic cancer is the best defence but it has so far proven elusive, as early symptoms often do not present and the placement of the pancreas deep inside the abdomen makes diagnosis difficult through noninvasive methods such as ultrasound.
Now, in a new study published in the journal Nature – Biomedical Engineering, a research team led by Tony Hu of the Biodesign Virginia G. Piper Center for Peronalized Diagnostics at Arizona State University has created an effective, quick and inexpensive method for testing the blood for certain biomarkers connected to pancreatic cancer. The innovation relies on detecting the presence of extracellular vesicles or EVs in the bloodstream. EVs are tiny bits of materials emitted by live cells into the extracellular space and which from there enter into the circulation throughout the body.
Importantly, research has shown that EVs can play a role in tumour growth by transmitting signalling molecules from cancerous cells and tissues to other cells. But the trouble has been in devising a way to identify the EVs associated with tumour growth. “Translating tumour EVs into cancer biomarkers has been challenging due to the lack of simple methods for EV analysis and of biomarkers that distinguish tumour-derived EVs from normal EVs,” say the study’s authors.
The new technique involves taking a small, teardrop-sized amount of blood and mixing it with two nanoparticles, both of which bind specifically with pancreatic cancer-derived EVs. The binding causes a change of colour that can be easily visible when viewed with a dark field microscope.
In the study, researchers applied the test to 59 people with the disease and found that it correctly identified pancreatic cancer in 90 per cent of cases. The study also looked at 48 healthy people and 48 with pancreatitis, an inflammation of the pancreas that can often be difficult to distinguish from pancreatic cancer. The new blood test was able to make the distinction.
Dr. Hu sees the new technique as an important advance. “Pancreatic cancer is one type of cancer we desperately need an early blood biomarker for,” says Dr. Hu in a statement. He estimates that a clinical translation of the new technique will likely take two to three years for regulatory approval.
The Canadian Cancer Society reports that an estimated 5,200 Canadians are diagnosed with pancreatic cancer each year and every year 4,700 people die from the disease. One of the so-called lifestyle cancers, pancreatic cancer strikes men as often as women and has known risk factors such as obesity, diabetes and smoking, along with family history of the disease and genetic conditions.