Pain still afflicts most cancer patients, mainly in the metastatic phases, and undertreatment is well documented. Transdermal delivery systems (TDS) could potentially have advantages over oral and parental routes, but evidence from comparative trials are scanty. In the framework of a wider initiative, an Outcome Research Study was carried out in Italy in 2006 to evaluate the effects of various analgesic options, particularly TDS Buprenorphine. Despite the limitations due to the observational design, these findings may be useful to clinicians to better judge the value of the drug under evaluation and to help researchers to design further comparative studies.