New screening test could reduce high mortality rates in patients with liver cancer

Primary liver cancer is one of the most common types of cancer in the world. Unfortunately, it is usually diagnosed far too late for treatment. As a result, it is the third most common cause of cancer-related death worldwide. Primary liver cancer occurs when tumours develop in the liver itself and have not spread from other parts of the body.

Dr. Jorge Filmus is a Senior Scientist at Sunnybrook Health Sciences Centre in Toronto. He has spent much of the last decade developing a revolutionary new test to proactively screen patients for liver cancer. This test would find tumours while they are still small enough to be removed, significantly reducing the disease’s high mortality rates.

“There is currently no effective cure for advanced liver cancer,” says Filmus. “By the time patients feel symptoms of the disease, the cancer has spread and there is almost no chance of curing it. But if we can use this test to detect a tumour when it is small, before it has spread, a surgeon can then go in and easily remove it. At that point a patient can make a full recovery.”

Filmus’ test uses antibodies to detect the presence of the biomarker glypican-3 in a patient’s blood. Patients at risk for liver cancer are people living with chronic hepatitis B or C or those with cirrhosis of the liver. They would have a blood test every six months to one year. Detection of glypican-3 would indicate that liver cancer is probably present in the body. Doctors could then locate the tumour and remove it.

Currently, most doctors use the alpha-fetoprotein (AFP) blood test or an ultrasound to diagnose the disease. “Neither are very good at detecting small lesions, which are the ones that we want to detect,” Filmus explains. “Looking for Glypican-3 is a good way to detect liver cancer because it is not produced by a normal liver. It is also not produced by a liver infected with hepatitis virus, or a liver that has non-cancerous lesions. Glypican-3 is only produced by malignant cells.”

The test could be easily adopted worldwide: it is simple and straightforward to perform and the technology is quite minimal. Filmus estimates that the final test could cost as little as $25 per patient. “The test is a very simple one that any clinical laboratory, even in developing countries, could perform with ease. Patients won’t have to go to a major hospital to get it.” An estimated $1 billion is spent each year worldwide on screening for liver cancer; this test could provide a better and inexpensive way to detect liver cancer at an early stage.

Chronic hepatitis leads to cirrhosis of the liver, which makes the liver prone to cancer. About 80 per cent of people who develop primary liver cancer have chronic hepatitis B or C. While hepatitis rates in North America are low compared to other parts of the world, the rate here has doubled in the last 15 years. Over 300 million people worldwide currently live with chronic hepatitis.

“We know who is at high risk of developing liver cancer. So we have a target population for screening that is quite large. Even if we make a conservative guess and say we will only be able to detect liver cancer at an early stage in 0.1 per cent of these people tested with the glypican-3 blood test, we’re still talking about saving many lives.”

The Ontario Institute for Cancer Research (OICR) recently awarded Dr. Filmus’ lab $280,000 to help commercialize the test for distribution. “Dr. Filmus’ research could change how liver cancer is diagnosed,” says Dr. Tom Hudson, OICR’s President and Scientific Director. “We could see this disease go from being one of the most deadly to one that, with the proper care, can be effectively managed. We are happy to support the development of this test and help to get it to patients sooner.”

Filmus says there is still some work to be done before the test is ready for clinical use. His lab is working with two companies, BioMosaics and Amorfix Life Sciences, to optimize the sensitivity of the test. “It’s one thing to have this work in a lab, but in an actual clinical laboratory it is much more complicated,” Filmus says. “You don’t want small errors to lead to misdiagnoses. But we are optimistic. We have identified new antibodies that will allow us to develop a better test.

“Better hepatitis vaccines may ultimately prevent much liver cancer,” Filmus adds, “but until that happens we need to diagnose it at an early stage before it spreads and becomes incurable.” That may sound like a small difference, but it’s a difference that could ultimately save millions of lives around the world.