Fatigue is the most common distressing symptom within the cancer experience.[1–4] Associated with all cancer treatment modalities, cancer-related fatigue (CRF) is differentiated by its predominance, its interference with normal daily functioning, and its unresponsiveness to usual attempts to reduce the subjective sense of tiredness. Its enduring nature across the cancer trajectory distinguishes it as a deterrent to a good quality of life, both during and after cancer therapy.
Historically, CRF has been unrecognized, misunderstood, under-managed and inadequately investigated. Yet CRF has potential sequelae that merit the attention of the cancer care team. Some of these negative corollaries include[1,5]:
● Discontinuation of the patient’s usual physical, social, interpersonal and recreational activities;
● Stress-related alterations in family functioning, roles, and responsibilities;
● Decreased job performance and work productivity;
● Reduced self-esteem;
● Problems adhering to antineoplastic treatments, including delays and interruptions;
● Therapy dose modifications due to unrelenting symptom distress;
● Withdrawal from clinical trials; and
● Reduced quality of life.
In the older adult with cancer, fatigue may cause significant functional dependence, with associated emotional, social, and economic burdens for patients as well as their caregivers.
Cancer-Related Fatigue in Older Adults
In healthy individuals, fatigue increases with age. It is generally attributed to a decline in the functional reserves of organ systems (ie, the “wear and tear over time”) that results in a negative energy balance. Fatigue in the elderly is compounded by the common presence of comorbidity, which further taxes the older adult’s capabilities. Other factors associated with fatigue in older adults include the prominence of immobility, deconditioning, nutritional compromise, and sleep disorders.
Despite the fact that cancer is a disease of aging, the negative corollaries of being old and having cancer have not been comprehensively studied. Paramount in this regard is the paucity of scientific investigation of fatigue parameters among older cancer patients. Two investigations at H. Lee Moffitt Cancer Center found that fatigue was almost universal in the elderly cohort studied.[2,7] A Canadian evaluation of fatigue in older women with breast cancer quantified its prominence and persistence both during and after cancer treatment. Researchers in Hong Kong documented a high prevalence of co-occurring pain, fatigue, insomnia, and mood disturbance in a convenience sample of 120 elderly patients receiving chemotherapy and radiation therapy. Research is needed to address the prevalence, patterns, and intensity of fatigue in older cancer patients, especially in comparison with younger adults. Characteristics specific to treatment type; elder age subset; and the relationship between fatigue and depression, degree of physical activity pre-diagnosis, and comorbidity (presence and types) are variables that should be investigated. Additionally, acknowledging the common presentation of fatigue within symptom clusters requires integration of this construct within research design.
Fatigue Assessment Approaches
Causation of CRF guides intervention planning.[3,4,11] Hence, an astute assessment of the etiologies of fatigue is critical. Physiological causes may be cancer-related (ie, the malignancy itself, its therapies) or related to other associated systemic processes (ie, anemia, infection, malnutrition, metabolic abnormalities). Etiologies may be biobehavioral in nature (ie, insomnia, pain) and/or psychologically based (ie, depression, worry, anxiety). Of special note in the context of gero-oncology is the perception by both patients and clinicians that fatigue is a benign complaint, a natural corollary of growing old and hence not worth reporting.[2,6,12] General measures to quantify CRF include its inclusion in multifocal symptom distress rating scales (often using Likert-formats to capture symptom intensity) and the use of more detailed instruments to distinguish the many components of fatigue.
Oncology nurses must maintain a heightened sense of alertness to those patients who are most at risk for symptom distress. While studies are lacking, clinical experience yields key perceptions about high-risk patients for CRF. Older patients undergoing treatment for leukemia, lymphoma, myeloma, and bone marrow transplantation represent one category of heightened risk. A second category includes older patients with advanced stages of cancer and intercurrent co-morbidity (ie, cardiac or renal impairment, diabetes).
Management of CRF in Older Adults
The treatment of CRF in elderly patients has been understudied. However, four seminal publications have outlined general evidence-based findings for the management of CRF.[3,4,11,14] These should be considered as interventions are explored for older adults with cancer.
Reducing the subjective and physiologic burden of fatigue in older adults with cancer is best addressed by three potential strategies: identifying and managing the etiologies of fatigue, prescribing medications, and utilizing nonpharmacologic approaches (ie, exercise and complementary therapies). Several caveats are in order as these are considered.
Physiologic factors causing fatigue in older adults may be more prevalent than what is identified in younger patient cohorts. Anemia and sleep disturbances may be especially problematic. The presence and mismanagement of comorbid illness may be a significant causative factor in patients with fatigue. The prominence of polypharmacy (often associated with comorbidity) should be determined, as potential adverse drug effects and interactions are of concern. Older adults are frequent purchasers of over-the-counter medications, the use of which is often not disclosed. The prescription of psychostimulants, antidepressants, and herbal supplements also warrants hypervigilance in terms of potential adverse effects related to fatigue.
Physical activity has the strongest supportive evidence as a nonpharmacologic intervention for management of CRF. Yet there is a paucity of information about the older adult’s experience with exercise during the cancer trajectory. Special considerations are warranted in the development of interventions for older adults with cancer using this modality[15-18]:
● Motivation and adherence to an exercise intervention are important parameters to measure;
● Prediagnostic integration of exercise into lifestyle behaviors may have a positive impact on regimen adherence;
● Type of exercise program (ie, energy conserving, aerobic, resistance, endurance or strength enhancing) must be considered;
● An exercise evaluation and should be performed;
● Monitoring physiologic parameters (ie, pulse, blood pressure, oxygen saturation) can assist with outcomes identification as well as indications for stopping an exercise intervention; and
● Development of exercise programs for patients with known compromise are needed (ie, presence of anemia and cognitive impairment, alterations in skeletal integrity) as are in-patient interventional models.
CRF in older adults is amenable to resolution by nursing oversight that includes early assessment and the selection of appropriate management approaches. Oncology nurses working with older patient populations at high-risk for CRF should partner with rehabilitation colleagues to create and test exercise interventions that reduce the burden of this common symptom. Additionally, establishing a national partnership between oncology nurse clinicians and nurse researchers could result in the identification of practical strategies to enhance the quality of survival of older adults treated for cancer who are impaired by the disruptive nature of CRF.
Financial Disclosure: The author has no significant financial interest or other relationship with the manufacturers of any products or providers of any service mentioned in this article.