The guideline raises our awareness of the facts that the specific pathophysiology and clinical causes of fatigue among cancer survivors are still poorly understood and that more research is greatly needed.
—Eduardo Bruera, MD
The majority of cancer survivors report different levels of cancer-related fatigue that can last for many years after completion of therapy. The American Society of Clinical Oncology has made a valuable contribution to care of adult cancer survivors by providing a simple and effective clinical practice guideline adaptation.1 The guideline, which is an adaptation of Pan-Canadian2 and National Comprehensive Cancer Network3,4 guidelines, is published in the Journal of Clinical Oncology and reviewed in this issue of The ASCO Post.
Detection and Evaluation
Universal screening using simple numerical scales is a very useful approach. The Pan-Canadian guideline adapted by ASCO has been effective in incorporating the screening for fatigue in cancer survivors with the screening for other possible physical and emotional symptoms in these patients, such as pain, anxiety, depression, and sensation of well-being, by recommending the use of multidimensional tools such as the numerical scale Edmonton Symptom Assessment System. This tool is completely free and can be completed in just a couple of minutes by patients attending their oncologist’s or primary doctor’s clinic.
For patients in whom fatigue is identified, the guideline proposes a more thorough assessment looking for contributing factors. In almost all patients, cancer-related fatigue is a multidimensional syndrome frequently associated with physical and emotional symptoms, deconditioning, and, occasionally, laboratory abnormalities.
The ASCO guideline has wisely chosen to recommend that laboratory evaluation be conducted on a personalized basis rather than using routine measurement of a large number of hormones, proinflammatory markers, and other laboratory tests that are expensive and have generally limited diagnostic accuracy.
With regard to management, the guideline also proposes a personalized approach. As it is in the case of fatigue associated with advanced cancer, it is important to correct all identified treatable contributing factors including polypharmacy, hypogonadism, hypothyroidism, deconditioning, and, very particularly, undiagnosed mood changes and sleep disturbances.
Increased physical activity and exercise are among the most useful interventions in this patient population. Most patients do not need referral to a specialist to be able to enroll in a program of increased physical activity.
Counseling, particularly cognitive behavioral therapy and other integrative interventions, can also be quite effective in selected patient groups.
The guideline wisely recommends caution before starting patients on pharmacologic interventions. These patients may need treatment for prolonged periods of time, and drugs that have been found to be effective in patients with fatigue associated with advanced cancer, such as methylphenidate or corticosteroids, have potentially severe side effects when used for long periods.
More Research Needed
Unfortunately, the majority of our currently available interventions for fatigue in cancer survivors have a mild to moderate effect size. The current practice guideline is extremely useful in promoting an approach that emphasizes limited invasive investigations, encourages a healthy life-style, and cautions against potentially risky pharmacologic interventions.
The guideline also raises our awareness of the facts that the specific pathophysiology and clinical causes of fatigue among cancer survivors are still poorly understood and that more research is greatly needed. Specifically, future research should be focused on identifying subgroups of patients in whom fatigue is associated with specific pathophysiologic abnormalities rather than gathering all comers under the label of “cancer-related fatigue in survivors.”
It is quite possible that some of the previously described interventions that are only mildly to moderately effective in the overall population of patients with cancer-related fatigue may be extremely effective in specific subgroups. In this regard, personalized therapy for fatigue will hopefully soon become part of future clinical guidelines. ■
Disclosure: Dr. Bruera reported no potential conflicts of interest.
1. Bower JE, Bak K, Berger A, et al: Screening, assessment, and management of fatigue in adult survivors of cancer: An American Society of Clinical Oncology Clinical Practice Guideline Adaptation. J Clin Oncol. April 21, 2014 (early release online).
2. Howell D, Keller-Olaman S, Oliver TK, et al: A pan-Canadian practice guideline and algorithm: Screening, assessment and supportive care of adults with cancer-related fatigue. Curr Oncol 20:e233-e246, 2013.
3. National Comprehensive Cancer Network: NCCN Clinical Practice Guidelines in Oncology: Cancer-Related Fatigue (version 1.2013). Available at www.nccn.org.
4. National Comprehensive Cancer Network: NCCN Clinical Practice Guidelines in Oncology: Survivorship (version 1.2013). Available at www.nccn.org.