Cachexia (wasting syndrome)

Cachexia is a complex change in the body, causing you to lose weight despite eating normally.

What is cachexia?

Cachexia (kak-ex-ee-a) is also called wasting syndrome or anorexia cachexia syndrome.

It is a complex problem that is more than a loss of appetite. It involves changes in the way your body uses proteins, carbohydrates, and fat. You may also burn calories faster than usual. People with cachexia lose muscle and often fat as well.

Cachexia is very different to general weight loss. Doctors can’t reverse it fully despite you being able to eat. Feeding through a tube is not effective either.

What happens in cachexia?

Scientists still don't know what exactly happens in cachexia. It is a complex process that involves several organs and systems in the body.

With cachexia, the cells in your muscles, fat and liver might not respond well to insulin. This is called insulin resistance. Insulin helps to take glucose from your blood. So your body can't use glucose from your blood for energy.

Scientists also think that cancer causes the immune system to release certain chemicals into the blood. This causes inflammation. These chemicals are called cytokines and contribute to the loss of fat and muscle.

The chemicals may make your metabolism speed up so that you use up calories faster. Because your body is using up energy faster than it is getting it, you can have severe weight loss. This can happen even if you are eating normally.

Symptoms of cachexia

Cachexia is more common in people with lung cancer or with cancers anywhere in the digestive system. The main symptoms are:

  • severe weight loss, including loss of fat and muscle mass
  • loss of appetite
  • anaemia (low red blood cells)
  • weakness and fatigue

Who gets cachexia?

People with early stage cancers don’t usually get cachexia. Up to 8 out of 10 people with advanced cancer (80%) develop some degree of cachexia.

Cachexia in advanced cancer can be very upsetting. You can feel very weak and less able to do things.

Cachexia isn't just associated with cancer. It is common in the advanced stages of other illnesses such as heart disease, HIV and kidney disease.

Losing muscle and fat can make it look as though you are wasting away. The side effects of your cancer treatment could make this worse. If you are worried or upset about changes to your body and cachexia, talk to your healthcare team. They will support you.

Research into cachexia

Researchers are trying to understand what causes cachexia and find new ways to treat it.

Causes of cachexia

Scientists still don’t fully understand why cachexia affects some people with cancer. Researchers are collecting information and blood samples from people with cancer and cachexia. They are trying to understand how and why it happens.

Treatment for cachexia

Some people with cachexia will be given medicines such as appetite stimulants. But these don’t work for all people. 

Ghrelin is an appetite regulating hormone found in the stomach lining. Anamorelin is a drug that mimics this hormone and improves appetite. Researchers have found that anamorelin might help people with cachexia. They found that it:

  • is safe
  • improved appetite
  • increased body weight and body mass
  • improved other symptoms

The results from research on anamorelin are promising so far. More research is continuing.

  • ESMO Handbook of Nutrition and Cancer (2nd edition) 
    A Jatoi, S Kaasa and M Strijbos
    ESMO Press, 2023

  • Quality standard for nutrition support in adults 
    National Institute for Health and Care Excellence (NICE), November 2012

  • Pharmacological management of cachexia in adult cancer patients: a systematic review of clinical trials
    S Advani and others
    BMC Cancer, 2018. Volume 18, 1174 

  • Cancer-associated cachexia
    VE Baracos and others
    Nature Reviews Disease Primers, 2018. Volume 4, 17105

  • Cancer-mediated muscle cachexia: etiology and clinical management
    T Siff and others
    Trends in Endocrinology and Metabolism, 2021. Volume 32. Pages 382-402

  • Cancer cachexia in adult patients: ESMO clinical practice guidelines
    J Arends and others
    Annals of Oncology, 2021. Volume 6, 100092

Last reviewed: 
14 Sep 2023
Next review due: 
14 Sep 2026

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