Steps toward Conquering Cachexia
by Egidio Del Fabbro, MD
The term cachexia 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. Consuming more calories will not reverse the loss of muscle and fat. And unlike starvation, which is always accompanied by an increased appetite, people with cachexia often have a poor appetite despite weight loss.
The combination of muscle wasting and loss of appetite that characterizes cachexia is driven by 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 by decreasing a person’s sensitivity to hormones that stimulate appetite and muscle growth.
Cachexia often has profound effects on a person’s quality of life. Changes in physical strength, appearance, and body image due to weight loss can provoke anxiety toward, and perhaps even inhibit, intimacy.
If you’re experiencing cachexia, meal times may become a source of frustration and conflict for you and your family. Your family members may have the false impression that you’re not trying, particularly when you feel full after just a few bites of food. Helping your family understand that early satiety and poor appetite are consistent with the condition of cachexia often helps to alleviate family anxiety and conflict.
If you’re experiencing cachexia, meal times may become a source of frustration for you and your family.
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, people with lung cancer or pancreatic cancer are more likely to lose weight than those with breast cancer, prostate cancer, or leukemia. Predicting a person’s risk of developing cachexia is a focus of on-going research, and early results suggest there may be a genetic predisposition. Identifying those who are at risk will enable physicians to introduce effective anti-cachexia therapies prior to chemotherapy. Many studies have shown that people are more likely to complete chemotherapy and experience fewer side effects if they are able to preserve their muscle mass.
Over the past five years, many advances have been made in our understanding of the complex mechanisms that cause cachexia. This scientific progress has stimulated the discovery of promising new therapies that are now in the final stages of placebo-controlled clinical trials.
Exciting anti-cachexia therapies on the horizon include an oral drug that mimics the effects of ghrelin, our main appetite-stimulating hormone. Other drugs specifically aimed at preserving muscle include selective androgen receptor modulators (SARMs) and myostatin inhibitors. SARMs are oral medications designed to produce some of the same benefits as testosterone, such as increased muscle size and strength, but without unwanted side effects, like increased hair growth and prostate enlargement. Myostatin inhibitors are drugs that target a protein that decreases muscle size and growth. When these new therapies complete final trials and demonstrate that they are both effective and safe, they could greatly benefit the estimated five million people in the United States coping with cachexia.
However, any new anti-cachexia medication will still need to be combined with comprehensive multidisciplinary treatment that includes expert symptom control, an individualized exercise program, and dietary counseling. This will require a team approach that may include a physician, dietitian, physical therapist, and psychologist.
Poorly controlled side effects, such as depression, constipation, pain, and nausea, can result in a decreased appetite and inadequate calorie intake. Fortunately, there are readily available, inexpensive therapies that can manage these issues effectively. Nutritional counseling has been shown to have a pronounced effect on individuals treated with radiotherapy for colorectal cancer or head and neck cancer. People who received nutritional advice from a dietitian enjoyed improved nutrition and quality of life, with fewer radiation side effects.
Any anti-cachexia program that aims to improve appetite, preserve muscle, and raise energy should also be combined with an exercise regimen for the best results. Because cachexia is still under-recognized by the medical community, you should alert your healthcare provider to any weight loss or decreased appetite you experience while undergoing cancer treatment.
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Dr. Egidio Del Fabbro is an associate professor and director of the palliative care program in the division of Hematology, Oncology, and Palliative Care at Virginia Commonwealth University in Richmond, VA.
This article was originally published in Coping® with Cancer magazine, September/October 2013.