It is estimated that around a third of cancer patients die because of cachexia – a syndrome characterized by muscle-wasting, weight loss, and metabolic changes that cannot be treated just by increasing food intake. Now, researchers have compiled a diagnostic tool comprising readily available measures and tests that could potentially extend survival in advanced cancer patients by helping to diagnose cachexia in its early stages – before it becomes irreversible.
Dr. Antonio Vigano, director of the cancer rehabilitation program and cachexia clinic at the McGill University Health Centre (MUHC) in Montreal, Canada, and colleagues report their findings in the journal Clinical Nutrition.
Dr. Vigano, who is lead author of the paper, notes:
“We are losing many cancer patients, not because of their cancer, but because their bodies have undergone important metabolic changes. In other words, they have simply stopped functioning correctly.”
The cause is a condition called cachexia, which affects
Cachexia typically involves extreme weight loss and wasting of muscle. As it advances, it impairs many aspects of quality of life and raises the risk of infection and other potentially fatal complications.
Once it becomes severe, increasing food intake does not reverse cachexia. Nutrients can no longer be absorbed or used by cancer patients, Dr. Vigano explains.
It is only recently that scientists have started viewing cachexia as a distinct, treatable condition. Previously, the focus had been mainly on the primary illness.
In the case of cancer cachexia, the researchers note that because of its inconsistent features, it is very difficult to diagnose. Dr. Vigano adds:
“In order to save more lives, we need practical and accessible tools that can be effectively used by clinicians in their routine practice to identify patients with cachexia.”
In their paper, the researchers describe how they compiled and tested a tool to “stage cancer cachexia patients and predict important clinical, nutritional and functional outcomes.”
The tool comprises five criteria – available from routinely available clinical measures and laboratory tests.
These include: results from biochemical analyses; measures of food intake and weight loss; and an assessment of patient functioning or performance status.
The team hopes the tool will be available for clinical use within the next few years. Before then, however, more studies are required to validate the new findings.
As well as cancer cachexia, the researchers hope the tool can eventually be applied to weight loss and muscle-wasting that is typically also seen in the late stages of many major diseases. These include: heart failure, chronic obstructive pulmonary disorder (COPD), kidney disease, AIDS, multiple sclerosis (MS), and tuberculosis (TB).
Dr. Vigano notes, however, that treatments will only be useful if doctors can diagnose cachexia and understand the severity of each case.
“Research is still needed to understand all the causes of cachexia. Unless we can talk the same language in terms of what type of patients we are treating and the severity of their condition, it is often very difficult to make substantial progress.”
Dr. Antonio Vigano