Fatigue
Summary of Key Points
Incidence
• Fatigue affects most patients with cancer, regardless of the stage of disease or the type of anticancer therapy used.
• Cancer-related fatigue (CFR) affects an estimated 80% to 90% of outpatients with cancer who receive either chemotherapy or radiation therapy.
• CRF can be persistent in cancer survivors.
• Determining the exact incidence requires standardized methods to define, diagnose, and measure CRF.
Staging Evaluation
• No standardized measurement tools exist except for International Classification of Diseases–10 criteria, which have not been widely adopted.
• Using National Comprehensive Cancer Network guidelines, patients report levels of fatigue using a numeric rating scale of 0 to 10. This numeric rating scale is currently used as a screening tool.
Primary Therapy
• No Food and Drug Administration–approved interventions are currently available.
• All treatable factors of fatigue should be addressed.
• Patients reporting fatigue should be enrolled in clinical studies relating to CRF whenever possible.
• The best evidence to date for improved outcomes related to CRF involve cardiopulmonary fitness through exercise, but further research in this area is needed.
• Stimulants may help severely fatigued patients near the end of life.
1. Which two of the following considerations are not important when using patient-reported outcomes to assess the quality of fatigue?
A Patients may experience a level of fatigue that prevents them from participating in continual assessment of their fatigue.
B A general quality of life assessment regarding fatigue provides the most clinically important information on fatigue.
C Functional assessments of fatigue can capture important fatigue information from most patients.
D Functional assessments of fatigue useful in neuromuscular fatigue conditions can provide important fatigue information for most patients with cancer.
2. Which of the following statements is true?
A Fatigue caused by anemia from anticancer therapy causes different patient experiences than anemia associated with chronic medical conditions.
B Patients with a solid tumor who are in the early stage and who are receiving anticancer therapy are not associated with severe fatigue because patients can receive erythropoietin-stimulating agents while receiving cancer treatments.
C Erythropoietin-stimulating agents should be investigated to improve exercise tolerance in severely fatigued patients with cancer.
D Anemia of any cause could prevent the benefits of exercise in regard to CRF.
3. Which of the following statements is true?
A Psychosocial interventions for CRF as outlined by the National Comprehensive Cancer Network guidelines can improve some components of sleep.
B Diminished cardiopulmonary reserve after anticancer therapy does not permit initiation of exercise training.
C Peak oxygen consumption (VO2peak) is a quantitative assessment of oxygen transport that could eventually be a marker of functional CRF.
D Exercise to improve cardiopulmonary fitness can also improve sleep quality in fatigued patients with cancer.
E Energy conservation is an important strategy to treat fatigue.
1. Answer: B and D. Patient-reported outcomes provide vital information about the patient experience if they are specific for the symptom or toxicity being studied. An assessment of quality of life includes many factors other than fatigue, which could overshadow fatigue and prevent it from being recognized. Measurements of fatigue from other disciplines will focus on the concerns of that population and miss patient reports of issues pertinent to cancer care and prevent a better understanding of cancer-related fatigue (CRF).
2. Answer: D. Cardiopulmonary fitness is dependent on oxygen delivery to the pertinent organ sites. Anemia can decrease the amount of oxygen delivered to a tissue such as skeletal muscles, preventing gains in peak oxygen consumption; this outcome can occur regardless of the cause of the anemia. Erythropoietin-stimulating agents are associated with multiple adverse outcomes and are only recommended for usage for patients with chemotherapy-associated anemia.
3. Answer: C. Recent clinical trials show a positive benefit of exercise to increase cardiopulmonary function in somewhat heterogeneous patient populations, and therefore it is hoped that this benefit will be sustained in further studies with more targeted patient populations. Neither exercise nor psychosocial interventions have been proven to improve sleep quality in patients with cancer. Given the promise of exercise, traditional energy conservation may become less important in the near future. Because two studies have shown that patients with breast and lung cancer have marked decrease in VO2peak compared with control subjects before and after therapy, it is most likely that cardiopulmonary function may not improve in these patients without an exercise-related intervention.
