One of the most long-lasting and frustrating sequelae of cancer is cancer-related fatigue (CRF). Although it is the symptom most often experienced by cancer patients from the time of diagnosis and throughout the lifetime of their disease, little is known about CRF except that it may persist for years after treatment is completed. Although the etiology of this distressing condition is unclear, oncologists believe cancer-related fatigue may comprise a number of biochemical and physiological organisms related to the patient’s type and stage of cancer and form of treatment. In a special report from the European Society of Medical Oncology (ESMO) Guidelines Committee, experts define cancer-related fatigue as “a distressing, persistent, subjective sense of physical, emotional, and/or cognitive tiredness or exhaustion related to cancer or cancer treatment that is not proportional to recent physical activity and that interferes with usual functioning.”1
Unlike people who experience other types of fatigue, those who suffer from cancer-related fatigue find that their condition does not improve with more sleep or rest. Researchers have found that cancer-related fatigue affects up to 65% of patients with cancer. More than two-thirds describe their fatigue as severe and lasting for 6 months or longer, the remaining patients reported feeling fatigued for years posttreatment. According to the ESMO Guidelines Committee, 40% of patients first experienced fatigue as they received their cancer diagnosis and 80% to 90% first reported feeling fatigued during radiotherapy and/or chemotherapy. Other possible treatment-related causes of CRF include chemotherapy/immunotherapy combination regimens, monoclonal antibodies, targeted therapies, and antiangiogenic agents. Endocrinologic disorders can interact with immunotherapy, and may cause fatigue as well. 1
Prevalence With Breast Cancer
Cancer-related fatigue is especially prevalent among survivors of breast cancer, according to Antonio Di Meglio, MD, of the Institut de Cancérologie Gustave Roussy in Villejuif, France. In an analysis he presented at the ESMO Breast Cancer Virtual Meeting 2020, Dr Di Meglio noted that oncology practitioners now have evidence-based strategies for treating the condition.2 Among them is the finding that patients should become less sedentary and more active. Other studies also confirm the effectiveness of interventions such as cognitive behavior therapy (CBT), which can help when patients are overcome by feelings of helplessness and/or distress.2
Dr Di Meglio and colleagues used data from 7000 patients in the CANTO cohort study (ClinicalTrials.gov Identifier: NCT01993498), which evaluated long-term toxicities in patients with early breast cancer and included clinical, patient-reported, and biological data. The researchers followed patients for a period of 5 years or longer after diagnosis.
Dr Di Meglio’s team only included women who were free of disease at the time of enrollment and who were at least 5 years out from treatment. They noted that 35% of participants were as fatigued at enrollment as they would have been only 3 to 6 months after treatment. Although 64% of patients followed the recommendations to be physically active, the remaining women were either significantly less active than they had been advised to be or they were completely inactive. Those patients who experienced severe fatigue at baseline were the least likely to increase their level of activity.
“The message here is that we need to work harder to encourage patients to stay active, and to make them understand that even if it seems counter-intuitive, it is exercise, not rest, that will help them to overcome fatigue,” explained Dr Di Meglio.2 Exercise can range from brisk walking or using a stationary bike with light effort to moderate-intensity resistance training.1