Safety of Fentanyl TAIFUN Treatment

Inclusion Criteria: * Age 18 Years or older * A medically documented diagnosis of cancer * Use of a fixed round the clock dose of opioid as maintenance therapy with a dose equivalence of at least 60mg of oral morphine/ day, or at least 25 mcg of transdermal fentanyl/ hour, or at least 30 mg of oral oxycodone daily, or at least 8 mg of oral hydromorphone daily. Current opioid treatment for at least 7 days prior to randomization * Current use of opioid medication for BTP * At least 4 episodes of BTP per week, with peak intensity of at least 4 on the NPS at pain onset. No more than 4 BTP episodes per day. * PIFR of at least 20L/min * Karofsky Performance Status of 40 or better * Life expectancy of at least 12 weeks * Written Informed Consent Exclusion Criteria: * Uncontrolled or rapidly increasing BTP * Symptomatic intracranial tumors or cerebral metastases * Persistent symptomatic asthma * Patients unable to use the inhaler * Inadequate lung function, as defined by PEFR \<60% * Hypersensitivities, allergies or contraindications to fentanyl or the study medication components * A recent history of alcohol or substance abuse (in the past 1 year) * Radiotherapy to the thorax within 30 days of the beginning of the titration phase * Cognitive impairment or any neurological of psychiatric disease which could compromise the ability of the patient to complete the assessments * Participation in any clinical study with an experimental drug within 30 days of randomization * Any clinical condition or medical history which, in the opinion of the investigator would not allow for the safe completion of the study or the safe administration of the study drug * Pre-menopausal women who are not surgically sterile and/or have a positive pregnancy test at baseline visit and/ or are of child bearing potential and are not using a reliable method of birth control or do not plan to continue using this method throughout the study and/or who are nursing