[Asthenia in cancer]

Asthenia in cancer patients is the most frequent symptom and probably one of the most disabling. Its right evaluation is essential to set an adequate therapy program. It is influenced by many factors, like anemia, anxiety and depression, sleep disorders, pain or malnutrition. Asthenia needs a multidisciplinary approach, and the best therapy is over this predisposing factors. Nevertheless, research about its ethiology, epidemiology and therapeutic options needs further studies to clearly define a better way to face this significant and, in so many ways, underestimated aspect of cancer patients. In this paper we review the present state of knowledge about asthenia in cancer patients and future possibilities open to research.