BY AMBER SMITH
One of the reasons liver cancer is so deadly is that people rarely discover the disease at an early stage, when it’s treatable.
What might help would be a screening test, similar to the one that exists for lung cancer. People at high risk for liver cancer could undergo medical imaging, and the resulting images could give doctors a peek at the liver without need for biopsy. Unfortunately, ultrasound, computerized tomography and magnetic resonance imaging cannot detect most liver cancer lesions, which are generally less than an inch big.
“An urgent need exists to develop new molecular imaging tools for diagnosis, response to therapy assessment and detection of recurrence of hepatocellular carcinoma,” the scientists write in a description of their work.
They want to use an imaging scan technique called PET, short for positron emission tomography. This is a sensitive quantitative molecular imaging method already in use for many types of cancer and other diseases. Most commonly, a fluorine-containing sugar (glucose) tracer molecule is injected into the patient, and a short time later the PET scan allows visualization of glucose metabolism in the patient’s body.
Cancer cells appear as bright spots on these PET images because they have higher metabolic rates, or burn more glucose, than do normal cells. But because the healthy liver cells metabolize lots of sugar, a PET scan using this tracer is not an effective test for liver cancer. The bright spots don’t discern cancer cells from normal cells.
The trick to being able to use PET for liver cancer will be to find a different tracer molecule, a task Krol says scientists have been working on for years.
He and Korendovych propose in their project to use a biological molecule that would be specific to liver cancer. The small fluorine-containing sugar molecule commonly used for PET would hitch a ride inside a larger molecule that already knows how to locate liver cancer cells, and it would remain attached to the liver cancer cell while a PET image is taken.
Krol says in the future, a PET scan for liver cancer could potentially provide an early warning system and replace the need for a biopsy to confirm liver cancer. Such an approach could possibly be used for other cancers, as well.
This article appears in the summer 2016 issue of Cancer Care magazine.