What is the pattern of not eating due to cancer or chemotherapy, specifically anorexia (loss of appetite)?

From the Guidelines

A pattern of not eating due to cancer or chemotherapy is known as cancer-related anorexia, and the most effective approach to manage this condition is to use a combination of nutritional support, appetite stimulants, and anti-nausea medications, as recommended by the most recent guidelines 1. To address this issue, patients should try eating smaller, more frequent meals throughout the day rather than three large meals. Cold foods often have less odor and may be more appealing when nausea is present. Nutritional supplements like Ensure, Boost, or Orgain can provide concentrated calories and protein when solid foods are difficult to consume. Some key points to consider when managing cancer-related anorexia include:

• Loss of appetite is common in patients with advanced cancer and may be the result of the cancer process itself 1
• Trying to force a patient to eat is usually counterproductive, potentially leading to increased nausea/vomiting 1
• In most patients with advanced cancer and cachexia, providing additional calories by feeding tubes and/or intravenously does not improve outcomes 1
• For patients with months-to-weeks or weeks-to-days life expectancy, consider the use of appetite stimulants (eg, megestrol acetate, dexamethasone, olanzapine) if increased appetite is an important aspect of quality of life 1
• A combination therapy approach may yield the best possible outcomes for patients with cancer cachexia, including medroxyprogesterone, megestrol acetate, eicosapentaenoic acid and L-carnitine supplementation, and thalidomide 1 Anti-nausea medications such as ondansetron (Zofran) 4-8mg every 8 hours, prochlorperazine (Compazine) 5-10mg every 6 hours, or dexamethasone 4mg daily may help manage chemotherapy-induced nausea. For appetite stimulation, medications like megestrol acetate (Megace) 400-800mg daily or dronabinol (Marinol) 2.5mg twice daily can be effective, although the evidence for dronabinol is limited 1. These interventions are important because maintaining adequate nutrition during cancer treatment helps patients tolerate therapy better, maintain muscle mass, and potentially improve treatment outcomes. The underlying mechanism involves cancer and chemotherapy triggering inflammatory responses that affect the hypothalamus, disrupting normal hunger signals and causing early satiety or food aversions. Ultimately, the goal of managing cancer-related anorexia is to improve the patient's quality of life, and a comprehensive approach that includes nutritional support, appetite stimulants, and anti-nausea medications, as well as consideration of the patient's prognosis and preferences, is essential 1.

From the FDA Drug Label

2.1 Anorexia Associated with Weight Loss in Adult Patients with AIDS 2.2 Nausea and Vomiting Associated with Cancer Chemotherapy in Adult Patients Who Failed Conventional Antiemetics 14.1 Appetite Stimulation

The pattern of not eating due to cancer or chemotherapy is related to anorexia and nausea and vomiting.

• Dronabinol is indicated for the treatment of anorexia associated with weight loss in adult patients with AIDS, but it is also used for nausea and vomiting associated with cancer chemotherapy in adult patients who failed conventional antiemetics.
• The drug has been shown to stimulate appetite. 2

From the Research

Pattern of Not Eating Due to Cancer or Chemotherapy

• Loss of appetite in patients with cancer is a common symptom that continues to trouble patients and is associated with poor survival 3.
• Recent preclinical research promises to lead to newer approaches and newer, more effective palliative agents for loss of appetite in patients with cancer 3.
• Agents such as olanzapine, anamorelin, and cannabis have been shown to palliate loss of appetite in patients with cancer 3.

Treatment Options for Loss of Appetite

• Megestrol acetate has been shown to be effective in palliating cancer-associated anorexia, with a greater percentage of patients reporting appetite improvement and weight gain compared to dronabinol-treated patients 4.
• Combination therapy with megestrol acetate and other agents has been shown to be effective in controlling chemotherapy-induced nausea and vomiting (CINV) 5.
• Megestrol acetate dispersible tablets with a 5-HT3 receptor antagonist and dexamethasone have been shown to better control CINV compared to a 5-HT3 receptor antagonist plus dexamethasone alone 5.

Chemotherapy-Induced Nausea and Vomiting

• CINV is a common side effect of chemotherapy that can lead to loss of appetite and weight loss 5.
• The use of megestrol acetate in combination with other antiemetic agents has been shown to improve CINV symptoms caused by highly emetogenic chemotherapy (HEC) with cisplatin 5.
• The triple antiemetic protocol using megestrol acetate with a 5-HT3 receptor antagonist plus dexamethasone has been shown to have an excellent control effect and few adverse reactions, especially for delayed CINV 5.