We hear a lot in the news about new tests for cancer but there is a reason that a potential new test for pancreatic cancer is something to get really excited about.
Based on data from 2009-2013, the estimated 5 year survival rate for pancreatic cancer is shocking, just 7.7 per cent.
We all know that cancer kills but with other types of cancer, particularly more common cancers, we have a better understanding and more ways to treat the disease. For example the 5 year survival rate for breast cancer is 90 per cent and for prostate cancer is 95 per cent.
So, why is pancreatic cancer difficult to diagnose?
Firstly, as with many cancers, pancreatic cancer may not lead to symptoms in the early stages. Those that may appear are often non-specific such as nausea, a change in bowel habits and loss of appetite. These could be caused by other common conditions, for example indigestion or irritable bowel syndrome so it is difficult for doctors to make a fast cancer diagnosis, and they will need to rule out other, more likely, causes first.
The location of the cancer within the pancreas can also determine how quickly it may be diagnosed. Cancers at the top of the pancreas that cause interference with the bile duct for example, may lead to symptoms quicker than those located at the other end of the pancreas – meaning there is more chance they will be picked up at a more treatable stage.
Pancreatic cancer is diagnosed by first using medical imaging such as ultrasound, CT scans, MRIs to locate the tumour and then confirming the presence of cancer through analysis of a tissue sample in a pathology laboratory. The sample may come from a tumour removed during surgery or via a biopsy.
Because pancreatic cancer is not common and due to the nature of the disease, we don’t have widely available screening tests like those available for other cancers – think mammograms and pap smears.
Why is pancreatic cancer so hard to treat?
As most patients don’t experience symptoms until their cancer is in a late stage, the cancer may have grown large and can also have spread (metastasized) to other organs such as the liver or lymph nodes.
Surgery to remove a tumour is most effective in the early stages of the disease as once the tumour has grown to other areas it can interfere with major blood vessels and other organs making it harder to remove.
An exciting development in testing
A team in California have been working on a blood test that could help to increase early diagnosis and therefore improve outcomes for pancreatic cancer patients.
Researchers from UC San Diego developed a method where a drop of blood is a placed on a small electronic chip, the current is then turned on and after a wait of several minutes, fluorescent labels are added, and the sample is examined under a microscope. If the blood sample tests positive for the pancreatic cancer protein biomarkers glypican-1 and CD63, then bright fluorescent circles will appear.
The research is published in journal ACS Nano, and first author Jean Lewis, an assistant project scientist in the Department of Nanoengineering at UC San Diego said;
“An important step towards being able to cure diseases that come out of nowhere, like pancreatic cancer, is early detection. We envision that in the future, physicians might perform this type of test using a quick finger stick to diagnose patients who may not know they have the disease yet.”
It may be early days, but this is an encouraging first step towards the possibility of an accessible screening test for those at higher risk, which would help to catch pancreatic cancer early.
*Image credit: Pancreapedia https://www.pancreapedia.org/reviews/anatomy-and-histology-of-pancreas