If you are an Health Care Professional

What causes Cancer Cachexia?

share via e-mail

What causes cancer cachexia?

In recent years, there has been much progress in our understanding of this complex syndrome.1 If you’ve already read the overview section ‘What is cancer anorexia-cachexia?’, then you will remember that this condition is due to two major processes acting together. The first is related to reduced food intake, or anorexia. The second involves metabolic changes due to cachexia, or wasting syndrome.

Why patients with cancer eat less

It is common knowledge that many patients with cancer often eat less than they did before their cancer. In fact, some families exhaust themselves trying to fight visible loss of weight and strength, urging them to eat even if there is no appetite, which is a source of frustration, helplessness, and fear.1 However, reduced food intake is likely to be the result of many different factors. While one of these may be loss of appetite, other problems such as difficulty in swallowing, nausea, and depression may be involved.2 Some people will also experience changes in taste and aversion to food.2

Depending on the type of cancer that an individual has, the symptoms associated with the cancer itself can also lead someone to eat less. These include discomforts such as abdominal fullness and constipation.3 Lastly, loss of appetite is a common side effect of many types of chemotherapy: people receiving chemotherapy may eat less than usual, not feel hungry at all, or feel full after eating only a small amount. Thus, reduced food intake is related to a variety of factors in patients with cancer.

More than just reduced food intake

One common impression is that cancer treatments in themselves cause weight loss, and indeed separating cancer anorexia-cachexia from the effects and complications of cancer therapy is often difficult.1 The loss of weight and muscle can be caused by surgery and many types of cancer therapies. For this reason, the progressive decline in health and weight can often be neglected.1 New studies have shown, however, that the cancer itself causes many profound metabolic changes.4 In fact, the cancer alters the body’s metabolism by modifying the synthesis and breakdown of amino acids and fats.5 Furthermore, it alters how the body responds to insulin, leading to changes in glucose levels. All these processes contribute to a reduction in muscle, body weight, and overall deterioration of general health and strength.5

Metabolic process Effect of cancer cachexia
Synthesis of muscle proteins Decreased
Breakdown of muscle protein Increased
Muscle Strength Decreased
Fat mass No change or decreased
Metabolic rate Increased
Response to insulin Increased

The metabolic consequences of cachexia5

A combination of factors

From the above, it should be clear that cancer anorexia-cachexia is a complex metabolic disorder characterized by weight loss and a change in body composition, and which is further worsened by reduced food intake.5 In fact, cancer cachexia may also be present in individuals who are overweight, which makes it difficult to diagnose in an increasingly obese population.1 This aspect will be further explored in the next section on how cancer anorexia-cachexia is recognized.


open references

This website contains resources related to healthcare professionals (HCP), for educational purposes only ("information"). This is a free service not linked to products or services, and provides no legal or contractual relationships.The information takes into consideration international rules and laws. This area may experience content changes at any time without prior notice to its users. In no event this fact will result in obligations or liabilities to the site. By clicking "Yes, I confirm I am a HCP" you confirm to be a healthcare professional and agree to comply with all the conditions detailed herein.

Yes, I confirm I am a HCP
Go Top