Cancer cachexia is one of the most common and serious complications of cancer, yet it has long remained in the background of cancer care. Characterised by loss of appetite, weight loss, muscle wasting and profound fatigue, it affects between 50% and 80% of people with cancer, depending on the tumour type and stage. Researchers estimate that cachexia contributes to 20–30% of cancer-related deaths because it can weaken patients, reduce their ability to tolerate treatment and significantly affect their quality of life.
For many years, cachexia was considered an unavoidable consequence of advanced cancer. As long as the focus remained on treating the tumour, relatively little attention was given to understanding cachexia itself. According to a recent Nature feature, that view is now changing. Researchers increasingly see cachexia as a complex condition in its own right, leading to a surge of research aimed at understanding its causes and finding ways to treat it.
One of the biggest changes has been in how scientists understand the condition. Cachexia is no longer viewed simply as malnutrition or weight loss. Instead, research suggests it is a whole-body syndrome involving multiple organs and biological processes. This helps explain why nutritional support alone cannot reverse the condition. Scientists are finding that changes in metabolism, inflammation and signalling between different tissues all contribute to the syndrome.
This new understanding has fuelled major international research efforts. In 2020, the Cancer Grand Challenges initiative funded CANCAN, a collaboration bringing together clinicians, scientists and patient advocates to investigate the biology of cachexia, identify biomarkers and explore potential treatments. The project has already produced dozens of scientific publications, alongside growing contributions from research groups around the world.
Researchers are also beginning to test therapies based on these discoveries. One approach targets GDF15, a signalling molecule involved in appetite regulation. In a mid-stage clinical trial, patients receiving an antibody against GDF15 gained weight and reported improvements in appetite and physical activity compared with those receiving a placebo. However, researchers interviewed by Nature stress that larger phase III trials are still needed, and there are currently no approved treatments for cancer cachexia in most parts of the world.
Although many questions remain, researchers believe the field has reached an important turning point. Cachexia is no longer seen simply as an inevitable consequence of cancer progression, but as a condition that can be studied, better understood and, potentially, treated. That shift in perspective is giving scientists—and patients—new reason for hope.
Coordinator at la Verneda-Sant Martí Learning Community and adjunct professor at the University of Barcelona