9th January 2024

Anorexia and Cachexia

Patients with malignancy often suffer from anorexia, or reduced appetite, and cachexia, which is the progressive loss of skeletal muscle and sometimes adipose tissue. Anorexia and cachexia often occur in parallel, and this is termed cancer anorexia-cachexia syndrome (CACS). CACS occurs in 15-40% of patients with cancer, increasing to 80% in those with advanced disease. It is especially common in those with pancreatic and gastric cancers. The resulting malnutrition is associated with reduced survival, as well as reduced benefit from treatments, including chemotherapy and reduced overall quality of life.

Cachexia can be broken down into primary causes, i.e., metabolic changes brought about by the cancer itself and secondary causes, i.e., dietary factors causing reduced oral intake, such as nausea, vomiting, chemotherapy-induced changes in smell and taste, constipation and obstruction from tumours, e.g., oesophageal.

When assessing patients with CACS, it is important to ensure reversible causes of anorexia are excluded and treated, e.g., pain, depression, anxiety, heartburn, ascites, medications, oral pain and biochemical abnormalities, including hypercalcaemia and uraemia.

Management of CACS

Treatment of cancer-associated cachexia is best achieved by removal of the malignancy, but this is unfortunately not always possible.

Involvement of the MDT is essential, with dieticians having a key role.

Non-Pharmacological:

Exploring the concerns of patients and their families around anorexia and explaining that appetite will often decrease can provide some reassurance.

Encourage any oral intake that the patient can manage, irrespective of nutritional or health benefit, and try to discourage carers from talking about food too much. Offer foods that are soft and easy to swallow, such as soup or pudding, or cold, plain foods with little odour.

Nutritional supplements have variable impact on body weight and nutritional intake in CACS, and don’t reverse cachexia but can be enjoyable and provide reassurance for the patient and their family.

Enteral and parenteral nutrition do not reverse cachexia and is not routinely recommended. It can have a role when patients are expected to have inadequate oral intake for several days, e.g., after surgery, and have a life expectancy of over two months.

Pharmacological:

Corticosteroids help in the short-term improvement of appetite and improve nausea and fatigue but do not impact overall nutritional status. They should be prescribed for 1 week and stopped if no benefit is seen during this time.

Progesterones, including megesterol acetate, improve appetite and calorie intake over several weeks, with effects potentially lasting for months. They cause weight gain, but this is due to increased fat mass instead of lean body mass.

Prokinetic drugs such as metoclopramide or domperidone can be used for nausea, gastroparesis, early satiety or delayed gastric emptying.