What causes fatigue during chemotherapy?

From the Guidelines

Fatigue during chemotherapy is primarily caused by the treatment's effects on the body's cells and systems, including the release of cytokines and inflammatory responses that signal the brain to induce fatigue, as well as the reduction of physical activity and the brain's central regulation of fatigue perception 1. The aetiology of cancer-related fatigue (CRF) is complex and not yet fully understood, but it is thought to involve multiple physiological and biochemical systems, including the skeletal muscles and the brain 1. Some of the key factors that contribute to fatigue during chemotherapy include:

• The treatment's effects on rapidly dividing cells, including cancer cells and healthy cells like those in bone marrow, digestive tract, and hair follicles
• The release of cytokines and inflammatory responses that signal the brain to induce fatigue
• The reduction of physical activity and the brain's central regulation of fatigue perception
• The production of pro-inflammatory mediators, such as interleukin (IL)-6, IL-1, and neopterin, which have been associated with CRF 1
• The incidence of endocrinological disorders, which can be a cause of fatigue when complicated by immunotherapy 1 It's worth noting that CRF affects almost 65% of patients with cancer, and up to 40% of patients report fatigue at cancer diagnosis, 80%-90% during chemotherapy and/or radiotherapy 1. Managing chemotherapy-related fatigue typically involves balanced rest and activity, proper nutrition, staying hydrated, treating anemia when necessary, and sometimes medications like methylphenidate or modafinil for severe cases 1. The most effective approach to managing fatigue during chemotherapy is a multifaceted one that takes into account the individual patient's needs and circumstances, and may involve a combination of lifestyle modifications, medical interventions, and emotional support 1.

From the FDA Drug Label

RETACRIT has not been shown to improve quality of life, fatigue, or patient well-being (1. 5). The FDA drug label does not answer the question.

From the Research

Causes of Fatigue during Chemotherapy

• Fatigue is a highly prevalent condition among patients with cancer, affecting between 70% and 100% of patients, and is described as the most distressing of symptoms 2.
• The exact causes of fatigue during chemotherapy are not fully understood, but it is believed to be related to a combination of factors, including the cancer itself, therapeutic interventions, and individual patient characteristics 3.
• Studies have shown that fatigue can be caused by various factors, including:
  • The timing and manner of chemotherapy administration 4.
  • The type of cancer and specific chemotherapy regimens 4.
  • Changes in sleep patterns and other symptoms 5.
  • The toxicity of chemotherapeutic agents 3.
• Fatigue can also be exacerbated by anemia, which is a common side effect of chemotherapy 3.
• The pathophysiology of fatigue is not fully understood, but it is thought to be related to a complex interplay of physiological, psychological, and emotional factors 6.

Patterns of Fatigue during Chemotherapy

• Fatigue is a relatively constant presence following chemotherapy, and its severity can increase over consecutive cycles of treatment 2.
• Fatigue can vary throughout the day, with more frequent occurrences in the afternoon and early evening 4.
• The pattern of fatigue can be influenced by the type of chemotherapy regimen and the individual patient's response to treatment 4.

Impact of Fatigue on Patients

• Fatigue can have a profound impact on a patient's quality of life, particularly in relation to physical functioning and the ability to perform activities of daily living 6.
• Fatigue can also be associated with considerable psychological distress and can impose a significant financial burden on patients and their families 6.