RCT comparing the analgesic efficacy of 4 therapeutic strategies based on 4 different major opioids (fentanyl, oxycodone, buprenorphine vs morphine) in cancer patients with moderate/severe pain, at the moment of starting 3rd step of WHO analgesic ladder.

INTERVENTION: Trade Name: MORFINA Pharmaceutical Form: Tablet INN or Proposed INN: Morphine Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 10‐ Trade Name: OSSICODONE CLORIDRATO Pharmaceutical Form: Tablet INN or Proposed INN: Oxycodone Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 40‐ Trade Name: FENTANYL Pharmaceutical Form: Transdermal patch INN or Proposed INN: Fentanyl Concentration unit: µg microgram(s) Concentration type: equal Concentration number: 25‐ Trade Name: BUPRENORFINA Pharmaceutical Form: Transdermal patch INN or Proposed INN: Buprenorphine Concentration unit: µg microgram(s) Concentration type: equal Concentration number: 35‐ CONDITION: Cancer patients with locally advanced or metastatic solid tumor. ; MedDRA version: 9.1 Level: SOC Classification code 10029104 PRIMARY OUTCOME: Main Objective: • The comparison of the analgesic efficacy of 4 treatment strategies based on 4 different strong opioids (oral morphine and oxycodone, transdermal fentanyl and buprenorphine) administered by randomization during a 4 weeks follow‐up period, in patients with moderate to severe pain due to the cancer, measured at each visit by means of a NRS 0 to 10, and related to the average pain of the previous 24 hours. Primary end point(s): Evaluation of the proportion of Non‐Responder (NR) patients. NRs correspond to the subjects who do not report any analgesic effects, with a P.I.D. (pain intensity difference) from visit 6 and visit 1 =/< 0%, (using a 0‐10 NRS ). It includes the situations of average pain intensity “stable” or “worsened” at day 28 compared with baseline values. Secondary Objective: • The evaluation of performance of the four opioids by means of the analysis of daily dose escalation (OEI%); the need of supplementary opioid doses finalized to support ATC treatment; the need of rescue therapy (due to BTcP treatment); the need of analgesic adjuvants finalized to support ATC therapy (and not to treat specific type of pain, such as neuropathic, bone, …); the need of switch in case of insufficient pain relief; the need of abandoning opioid therapy for unresponsiveness. INCLUSION CRITERIA: 1.patients with diagnostic(histological or cytological) evidence of locally advanced or metastatic solid tumour; 2.with average pain intensity = 4, measured with NRS and related to the last 24 hours, due to the cancer, requiring for the first time an analgesic treatment with 3rd step/WHO opioids 3.with life expectancy > one month 4.“strong” opioid na?ve; 5.eligible to take any of the medications under evaluation, by TDS or by mouth; 6.with age = 18 years; Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18‐64 years) yes F.1.2.1 Number of subjects for this age range F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range