[Drug therapy of pain in oncology: keep it simple!].

Pain is the most common symptom in patients suffering from cancer, in particular for advanced diseases. Unfortunately, one third of the patient do not benefit from optimal pain control. One must stress the importance of defining the etiology of pain and subsequently its pathophysiology. This thorough evaluation can help to formulate a proper strategy for a treatment of pain that could be adapted to the disease evolution. A multidisciplinary approach with respect to the WHO prescribing criteria is the most appropriate way to control severe cancer pain syndromes.