Opioid Titration With 12.5 ug/h Fentanyl Transdermal Patch vs Orally Morphine for Opioid-naïve Patients With Moderate Cancer Pain

Inclusion Criteria: 1. Age 18 years old or more; 2. ECOG PS ≤3 ; 3. Opioid tolerance not moderate pain patients (4≤ NRS ≤6 on 11 points, 0 no pain, 10 most pain); 4. No taking strong opioids for the last 30 days; 5. Estimated life expectancy of at least 3 months; 6. Ability to communicate effectively with the study personnel about the nature of their pain; 7. Ability to complete a diary; 8. Cancer pain is expected to be relatively stable and last for more than 48 hours; 9. The patient understands the research process, agrees to participate in the trial, cooperates with the treatment and visit plan, and signs an informed consent form. Exclusion Criteria: 1. Known allergy to any ingredient in both fentanyl and morphine; 2. No cancer associated pain or the pain of unknown cause, such as osteoarthritis pain, acute abdominal pain; 3. Primary tumors or metastases in the brain; 4. An active skin disease that precluded application of the transdermal system; 5. Anti-cancer therapy (radiotherapy, chemotherapy, targeted therapy, etc.) is used during the study period, and the treatment has an impact on the analgesic effect or adverse reactions of analgesic drugs; 6. No bowel movement within 3 days before the screening period; 7. The patient has contraindications to the use of opioids: such as respiratory depression; head damage; paralytic intestinal obstruction; acute abdomen; chronic obstructive airway disease; pulmonary heart disease; chronic bronchial asthma; hypercapnia; 8. Used monoamine oxidase inhibitor within 1 week before randomization; 9. Any abnormal laboratory test results with obvious clinical significance, such as creatinine value ≥ 2 times the high limit of the normal value or ALT or AST ≥ 2.5 times the high limit of the normal value (for patients with liver metastases can be relaxed to ≥ 5 times the high limit of the normal value) ; 10. Patients with a history of drug abuse; 11. Patients with mental illness or cognitive impairment; 12. Pregnant or lactating women; subjects who have a pregnancy plan within 1 month after the test (including male subjects); 13. Participate in the drug trial (including the trial drug) within 3 months before the trial.