Cancer-related fatigue

Cancer-related fatigue or CRF may refer fatigue caused by cancer that begins before cancer treatment, or fatigue that begins during cancer treatment, which is also known as Post-cancer Fatigue or PCF.

Cancer-related fatigue is an excludes the diagnosis of chronic fatigue syndrome when symptoms can be fully accounted for by cancer-related fatigue. People with pre-existing ME/CFS may experience a significant increase in fatigue after developing cancer.

Differences from ME/CFS

Disease process

Cancer-related fatigue and chronic fatigue syndrome have some similarities but are believed to have different underlying disease mechanisms, and affect the body differently. Fatigue can be one of several early symptoms of cancer, or may be triggered by cancer treatment. Differences include different EEG findings, different hs-CRP levels and different heart rate variability.

Symptoms

Post-exertional malaise (PEM) is increasingly regarded as the hallmark symptom in ME/CFS, but is only found in a minority of people with cancer-related fatigue.

Cancer-related fatigue was found to more closely linked to sleep quality, anxiety and depression compared to chronic fatigue syndrome.

Diagnostic criteria

Cancer-related fatigue cannot be diagnosed without a clear test indicating that cancer is present. ME/CFS is not diagnosed if an alternative explanation is present for the symptoms, such as an untreated fatiguing illness, although this does depend on the diagnostic criteria used.

Risk factors

Triggers and risk factors differ significantly between ME/CFS and cancer-related fatigue.

Treatment

Treatment for chronic fatigue syndrome differs significantly from the treatment of cancer-related fatigue.

Learn more

• Spotting the difference: Cancer related fatigue vs everyday fatigue - Leukaemia Care

heart rate (HR) - the number of times the heart beats within a certain time period, usually a minute

post-exertional malaise (PEM) - A notable exacerbation of symptoms brought on by small physical or cognitive exertions. PEM may be referred to as a "crash" or "collapse" and can last for days or weeks. Symptoms can include cognitive impairments, muscle pain, trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, and others.