Effects of transdermal buprenorphine on patients-reported outcomes in cancer patients: results from the Cancer Pain Outcome Research (CPOR) Study Group.

OBJECTIVES: Pain still afflicts most cancer patients, mainly in the metastatic phases, and under-treatment is well documented. Transdermal delivery systems (TDS) containing fentanyl or buprenorphine could potentiality have advantages over oral and parenteral 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 buprenorphine TDS.

METHODS: This is a multicenter, open-label, prospective, nonrandomized study. Data were collected using a web-based standardized system, with a follow-up up of to 3 months. Pain intensity, the primary outcomes of the study, was measured using 11-point numerical rating scales from the Brief Pain Inventory.

RESULTS: One-hundred ten centers recruited 1801 cases, most of which (60%) were receiving a strong opioid at the time of inclusion. Of these, 257 had TDS buprenorphine as first choice. Of the remaining 709 patients who at the time of inclusion were not on a strong opioid, 325 changed to a strong opioid and in 43% it was TDS buprenorphine. During the follow-up, physicians had to increase the dosage to control pain (average increase between 16% and 17%). About 34% of patients had an improvement of at least 2 points in worst pain, 15% had a 20% improvement in pain relief, and 40% in satisfaction. Results were in line with those of patients receiving other World Health Organization-level III opioids.

CONCLUSIONS: Despite the limitations owing to the observational design, these findings may be useful to clinicians to judge the value of the drug under evaluation better and to help researchers design further comparative studies.