gms | German Medical Science

A large number of cancer patients experience fatigue during the course of disease either as a side effect of treatment or as a disease symptom. In some cases fatigue can continue for many years once treatment has ceased. Fatigue as a common symptom can seriously impair the patients quality of life and has various implications for the patient's adaptation and social integration. Studies in epidemiology show overall prevalence rates ranging from 59%-96%. Although there has been a lot of active research within the last decade, a comprehensive theory explaining the causes of the various phenomena of fatigue is still lacking. There are numerous factors discussed on the causes of fatigue including medical conditions, biochemical or pathophysiological factors or psychological factors. In the recent scientific discussion the concept of fatigue is based on a multi-dimensional approach focusing on physical, emotional and cognitive aspects. Studies on psychosocial factors are focusing on the correlation between fatigue and depression as well as anxiety. Fatigue is a common symptom of depression and has been associated with anxiety and depression. Nevertheless the interdependence between fatigue and depression or anxiety is not yet completely explained. There are only a few studies investigating the complexity of interactions between physical and psychological aspects of fatigue. But fatigue is not only affecting the individuals QoL, but has a lot of consequences on health economy as well as the vocational integration. Patients complaining about fatigue show a higher demand rate of physician counselling, private practitioner or other health services. In the same way, they show higher rates of sick leave and loss of work capacity. Some studies show that the rate of reemployment is influenced not only by the cancer diagnosis but also by the fatigue syndrome. Therefore, cancer related fatigue has to be focused in rehabilitation programs to help the patients to cope with the sequelae in terms of activities of daily living as well as their work situation.