Charles Loprinzi, MD	Debra Barton, RN, PhD

Fatigue is a common symptom of people with cancer—about 70% to 90% of people experience fatigue during and after treatment. It can seriously affect a person’s daily activities, including the ability to work, be involved with family, or socialize. To learn more about fatigue and what people with cancer can do to better manage it, Cancer.Net talked with Charles Loprinzi, MD, and Debra Barton RN, PhD.

Q: What is fatigue and how does it differ from tiredness?

A: “Fatigue” and “tiredness” are often used to describe the same feeling. The more pressing question, we believe, concerns the difference between cancer fatigue and the more usual fatigue that people can get from lack of sleep and working too hard. Cancer fatigue is considered to be a kind of fatigue that does not get better with rest. It is also a deep fatigue that is not explained by the amount of activity one does. Cancer survivors describe it as a feeling of heavy arms and legs, an inability to think, and a lack of energy for many usual activities.

Q: What are the causes of fatigue in patients with cancer who are not receiving cancer treatment, and what are some ways to manage it?

A: There are multiple causes for cancer fatigue, independent of cancer treatment. Not all of them are well understood. Nonetheless, some are related to substances secreted by the cancer itself and/or the body in response to the cancer process. Some of these substances cause anorexia, a loss of appetite. This leads to decreased nutrition and can add to fatigue. Other cancer-secreted substances can also cause anemia (an abnormally low level of red blood cells that contain hemoglobin, which carries oxygen to all parts of the body) and electrolyte (such as sodium or calcium) imbalances. Abnormal amounts of both of these may cause fatigue. Pain associated with cancer can also interrupt sleep, which leads to fatigue.

In terms of ways to manage cancer fatigue, correction of abnormal blood counts and electrolytes may help resolve cancer fatigue. Thyroid function should also be corrected if it is abnormal. Resolution of pain, nutritional, and sleep troubles may also be helpful. Nonetheless, these measures often stop short of totally improving fatigue.

For a long time, recommendations centered on maintaining rest and trying to reserve strength for necessary activities. However, we know that too much time in bed or at rest can actually increase fatigue through a process called “deconditioning.” The best information available to date is that a regular exercise program, as opposed to a regular resting program alone, is the best thing to help alleviate cancer-related fatigue.

Although exercise has been studied and found the most helpful to date, it still does not totally manage this problem in most patients. There have been efforts to study medicinal substances for improving cancer fatigue. Erythropoietic agents (medications that help treat anemia caused by chemotherapy) to increase red blood cells have been studied, with maybe a little bit of success. However, there have been recent concerns with regards to the use of these agents in patients with cancer that have decreased their use. Antidepressants have also been studied in patients without established depression, but these do not appear to be helpful. Other medications, such as modafinil (Provigil), which is a stimulant approved for the treatment of excessive daytime sleepiness or narcolepsy, have looked moderately promising. A recent randomized placebo-controlled trial shows that it may be helpful in those with more severe fatigue. In addition, data from a placebo-controlled pilot trial (an initial study examining a new method or treatment), have suggested that the herbal agent, Wisconsin ginseng, looks promising for improving cancer fatigue.

Q: What are the main causes of fatigue in people undergoing cancer treatment, and what are some ways to manage it?

A: In addition to the cancer itself causing fatigue, cancer treatments can cause fatigue. This applies to radiation therapy and multiple drug therapies, including, most notably, chemotherapy and interferon treatment. The toxic effect of these treatments on normal body cells is the cause for this fatigue. Thyroid changes can result from some cancer treatments and can also cause fatigue. Some chemotherapy and newer targeted therapies can cause low levels of magnesium, which might be responsible for fatigue. Other issues that can make fatigue worse during treatment are poor nutrition, not drinking enough fluids, and stress and anxiety.

As far as treatment options, again, exercise has the best evidence of efficacy. The other drugs discussed above are also of possible benefit. Studies done to date have shown that different types of therapies, such as radiation therapy or different cancer drugs, result in similar fatigue. One option, for patients with advanced cancer whereby chemotherapy may have limited benefit, is to take a temporary break from the chemotherapy.

Q: What are some tips for patients on talking with their doctors about fatigue?

A: As with most things, patients should be honest with their doctors and tell them the symptoms that are bothering them. Likewise, they should tell their doctors about others issues, discussed above, which might relate to fatigue. This includes issues with depression, pain, and trouble sleeping. They should tell their doctors whether they’re on a regular exercise routine and, if not, the reasons for not exercising.

Q: What research is ongoing with fatigue in people with cancer?

A: Ongoing studies to reduce fatigue are looking at additional exercise programs, including yoga and resistance exercise. Other ongoing clinical trials are evaluating acupuncture and sleep interventions to try to help with fatigue. Also, studies are addressing the utility of medicinal substances, such as ginseng and psycho-stimulants. Much of the current research is trying to understand the physiologic (physical and chemical) changes in the body from cancer and cancer treatment that can lead to fatigue, so that better treatments can be developed to help this important symptom.

Dr. Loprinzi is Professor, Oncology, at Mayo Clinic in Rochester, Minnesota.

Dr. Barton, also at Mayo Clinic in Rochester, is a PhD-trained nurse scientist who conducts extensive research on fatigue.

More Information

Managing Side Effects: Fatigue

Cancer.Net Feature: Coping With Cancer-Related Fatigue

Additional Resources

CancerCare: Finding New Ways to Cope With Fatigue

National Cancer Institute: What To Do When You Feel Weak or Tired (Fatigue)