Managing Cachexia During Cancer Treatment

by Egidio Del Fabbro, MD

The word cachexia has Greek origins and generally means “poor condition.” As a medical term, it refers to a specific condition characterized by involuntary weight loss, poor appetite, and muscle wasting. It is important to note that cachexia is quite different from starvation. During starvation, our bodies attempt to preserve muscle by using fat for energy, but in cachexia, both muscle and fat are lost. Unlike starvation, which is always accompanied by an increased appetite, individuals with cachexia may have a poor appetite despite weight loss.

The dominant mechanism that produces muscle wasting and poor appetite is a deviant inflammatory response. Proteins called pro-inflammatory cytokines are produced in excess and activate enzymes that break down muscle cells. Cytokines also hinder the muscles’ efforts at rebuilding, and they decrease sensitivity to ghrelin, the main appetite stimulating hormone produced by our bodies. Appetite may also be diminished by a variety of treatable symptoms, including depression, constipation, pain, early satiety, and altered taste. The majority of people referred to our cachexia clinic have at least two or more of these treatable symptoms.

Cachexia may have profound effects on one’s quality of life. Instead of a time of warmth and togetherness, meal times may become a source of frustration and conflict for individuals and their families. Families may have the false impression that their loved one is not trying, particularly when the individual experiences a “full feeling” after just a few bites of food. An understanding that early satiety and poor appetite are consistent with the condition of cachexia helps alleviate family anxiety and conflict.

Cachexia is characterized by involuntary weight loss,
poor appetite, and muscle wasting.

The changes in appearance and body image as a result of weight loss may provoke anxiety in the individual and perhaps even inhibit intimacy. Individuals may need to make their healthcare providers aware of these concerns, as well as others related to decreased strength and difficulty performing tasks at home or work.

It is unclear why some people experience cachexia and others do not, although the type of cancer does seem to play a role. For example, individuals with lung cancer or pancreatic cancer are more likely to lose weight than those with breast cancer, prostate cancer, or leukemia. The size of the tumor does not necessarily correlate with increased weight loss, and individuals may experience fatigue and muscle loss long before the diagnosis of cancer is made. Trying to predict a person’s risk of developing cachexia is a focus of ongoing research and would enable physicians to introduce therapies soon after diagnosis for those with an increased risk.

Cachexia challenges not only people battling cancer, but also some with rheumatoid arthritis, congestive heart failure, and chronic infections such as HIV, tuberculosis, and malaria. Treatment directed at the cause of the illness, whether it be a cancer cell, bacterium, or virus, will reverse cachexia. Muscle wasting and weight loss are likely to improve when a cancer responds to therapy. In turn, people are more likely to complete chemotherapy and experience fewer side effects if their cachexia is not severe. Therefore, treatment directed at muscle preservation and appetite should be started soon after diagnosis and be seen as complementary to cancer therapies such as chemo or radiation.

Fortunately, the increased scientific interest in cachexia has stimulated the creation of promising therapies that could halt the breakdown of muscle, encourage muscle growth, and increase appetite. These new drugs and hormones have only completed small preliminary trials and need to be tested in larger placebo controlled trials. Since there are so many factors that contribute to the development of cachexia, it is likely that more than one medication will be required.

An individualized exercise program is likely to be an important aspect of any treatment since multiple studies have shown that exercise is an effective therapy for the severe fatigue experienced by people with cancer. Studies that are more recent suggest resistance training may help preserve muscle size and strength.

Comprehensive multidisciplinary therapy of cachexia may require treatment by an oncologist, a dietician, a physical therapist, a psychologist, and a physician experienced in symptom management. This multimodality approach should be initiated as early as possible in order to provide the best chance of preventing muscle loss, decreasing fatigue, and completing cancer treatment.

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