Prospective Longitudinal Observational Study to Evaluate the Clinical Characteristics and Opioids Treatments in Patients With Breakthrough Cancer Pain

Inclusion Criteria: * diagnosis (histologic or cytologic) of locally advanced cancer and / or metastatic disease; * presence of baseline pain of moderate intensity / severe, necessitating treatment with opioids of the 3rd step / WHO, already in progress or to be undertaken at a stage just prior to the start of the study (see also criterion 4 where indicates that "the pain of base must be adequately controlled with opioids of the wHO 3rd step"); * estimated life expectancy of more than one month; * presence of BTCP, diagnosed according to the criteria set by the definition of BTCP and the algorithm of Davies, for which it is established to undertake a treatment "rescue" of painful episodes, with the appropriate opioid drugs at the time of commencement of the study; * capable of taking opioid medications for pain basic and breakthrough pain, by any route of administration; * aged more than 18 years. Exclusion Criteria: * participation in other research projects that are in conflict or could confound the results of the study; * absence of informed consent, or withdrawal of consent for study participation; * presence of some pathological mental or psychiatric conditions, due to the tumor or concomitant diseases, which interfere with the state of consciousness or the ability to judge the point of jeopardizing the study protocol; * need treatment for comorbid conditions present at the beginning of the study that could create potentially dangerous drug interactions with opioids (conazolici use of antifungals or macrolide antibiotics); * contraindications of any kind for use of opioid drugs; * positivity of a story, past or current, of substance abuse; * inability to ensure regular follow-up; * diagnosis of primary tumor of the brain; * situation of the presence of BTCP already in treatment with opioid rescue of 3rd step; * decision to use drugs "rescue" of different opioid 3rd step / WHO (NSAIDs, opioids of 2 ° step), for the treatment of BTCP; * diagnosis of chronic renal failure proclaimed already in place, with values of blood creatinine ≥ 2 mg / dL.