Sebastiano Mercadante1,2,3,4. 1. Anderson, University of Texas, Houston, USA. terapiadeldolore@lamaddalenanet.it. 2. Department of Palliative Care and Pain Therapy, University of Palermo, Palermo, Italy. terapiadeldolore@lamaddalenanet.it. 3. Anesthesia and Intensive Care Unit and Pain Relief and Supportive Care Unit, La Maddalena Cancer Center, Via San Lorenzo 312, 90146, Palermo, Italy. terapiadeldolore@lamaddalenanet.it. 4. SAMO, Home Care Program, Palermo, Italy. terapiadeldolore@lamaddalenanet.it.