• Dropout rate due to adverse events (AEs) at day 0, 7, 14 and 28.
  

• Clincial Utility and Safety at day 0, 7, 14 and 28.
  

Fentanly, a synthetic opioid, has been extensively and successfully used for the control of chronic pain. The transdermal therapeutic system (TTS; Durogesic) was developed and approved in the US in 1991, and has since been approved in approximately 45 countries. The system consists of a rate-controlling membrane providing constant release of fentanyl at a controlled rate for up to 72 hour, making it well suited to the treatment of chronic pain. New matrix form "Durogesic DTRANS", will use in the same indication with the old form. This controlled-release patch formulation offers the advantage of achieving more consistent drug delivery in a convenient, noninvasive way and could contribute to improved patient adherence to therapy. This study is designed to investigate the safety/tolerability and clinical utility of low dose TTS-F in Taiwan patients with cancer pain, meanwhile, demonstrate the drop out rate will be decreased by initiating therapy with12 microgram per hour instead of with 25 microgram per hour.This is a single-arm, non-randomized, open-label study. 600 eligible patients will be enrolled and scheduled to return at Days 0, 7, 14 and 28 for safety/tolerability and clinical utility assessments. The primary endpoint is the dropout rate due to Adverse events. Safety assessments consist of physical examinations and vital signs, clinical laboratory evaluation, and monitoring for adverse events. Pain severity, patients' Quality of Life, Dosing and Titration Requirements, Investigator's Global Assessment and Patients' Satisfaction will be evaluated as clinical utility.The screening will last up to three weeks. Patients with cancer pain who meet entrance criteria for the study will be identified. The study will be explained and informed consent will be obtained. Patients who have met the criteria at screening will start approximately 28-day treatment.Throughout the treatment, dose adjustments are permitted at each patch renewal (every 3 days).The initial dose of TTS-F will be administered at 12 microgram per hour.The dose should be titrated in consultation with the treating physician and according to the patient's analgesic requirement, with the intention of maintaining his/her pain score at 2 or less by mean of the past 3 days' Numeric Rating Scale (NRS). Oral morphine could be used as rescue medication if necessary for breakthrough pain. Steroidal anti-inflammatory drugs, NSAIDs, adjuvants (antidepressants and antiepletics, laxatives, mild antiemetics and 5HT3-blockers) are allowed to be prescribed by the treating physician deems the necessity. The lowest dose is designated as 12 microgram per hour (however, the actual dose is 12.5 microgram per hour) to distinguish it from a 125 microgram per hour dose that could be prescribed by using multiple patches. Each patch should be applied to nonirritated, non-irradiated, and hair-free skin, on a flat surface such as the chest, back, flank, or upper arm, and worn for 72 hour.

The initial dose of DTRANS transdermal patch will be 12 microgram per hour. The dose should be titrated in consultation with the treating physician and according to the patient's analgesic requirement, with the intention of maintaining his/her pain score at 2 or less by mean of the past 3 days' Numeric Rating Scale. The duration of the treatment will be 28 days.