Pictured: Research team lead Dr. Michael Sawyer and co-author Dr. Judith Meza-Junco.
Patients waiting for liver transplants may be prioritized differently in the future, thanks to new research from the Faculty of Medicine & Dentistry.
Michael Sawyer, Judith Meza-Junco and Aldo Montano-Loza led an investigation of sarcopenia, the deterioration of muscle mass, in liver cancer patients who are waiting for liver transplants. Their research centred around the effects of lean body mass on chemotherapy toxicity. Sawyer and Meza-Junco work in the Department of Oncology while Montano-Loza works in the Division of Gastroenterology, Department of Medicine.
"We wondered if low amounts of muscle were the cause of the advanced liver cancer patients not tolerating the drug sorafenib," Michael Sawyer, research team lead, said referring to a new treatment reserved for patients with well-functioning livers. "We wondered if we could identify patients who could tolerate treatment from a group that were declared too sick by current testing methods."
Two methods are currently used to determine how far a patient's liver disease has advanced: the Child-Pugh and the Model for End-Stage Liver Disease (MELD) scores. The MELD test is also used to prioritize patients for transplant lists. Patients who receive low scores on these tests have a higher chance of survival and are given lower transplant priority.
Using CT images, Meza-Junco determined the lean body masses of 116 liver cancer patients who were being evaluated for transplant. While the results did not successfully identify patients for treatment, a pattern emerged. CT scans revealed that patients with very low amounts of lean body mass lived roughly half as long as their more muscular counterparts. The exact numbers were, on average, 16 months versus 28 months for patients with normal amounts of muscle mass.
When CT scan results were compared with patients' MELD and Child-Pugh test scores, the data suggested a different wait list ranking. Some of the patients with low test scores, suggesting they would be the healthiest, had less muscle mass than some patients with higher test scores.
"Some of these people would have appeared lower on the list for a transplant. When you look at them this way, they're actually much sicker and should be transplanted earlier," Sawyer said, also noting that livers for transplant are difficult to obtain.
Nutritional status, which is marked by dietary habits and fitness level, is not used to evaluate a patient's need for transplant due to potential biases in perception. CT scans, on the other hand, produce exact information and do not expose patients to any superfluous testing - liver disease patients have regular CT scans to follow the progress of their illness.
"This is the first published information about liver cancer and sarcopenia. It's a very good start and we need to continue," co-author Meza-Junco said of the results, noting that more research is needed before low amounts of lean body mass can be used as a factor to determine transplant priority. "The MELD and Child-Pugh are very old scores and have been used for decades. The MELD score is used everywhere in the world so it's probably going to be very hard to add the sarcopenia or low body mass form. I do think it's going to be something very important to consider in patients who could receive transplants."
This study was published in the Journal of Clinical Gastroenterology.