Authors’ contributions KHK coordinated the study and drafted the manuscript, EB conceived the study and participated in its design and coordination and helped to draft the manuscript, PT conceived the study and participated MK-4827 clinical trial in its design and coordination, AB carried out the histology and immunohistochemical studies and helped to draft the manuscript, MB carried out the histology and immunohistochemical studies, CT and helped to draft the manuscript, AC participated in its design

and coordination, IP carried out the histology and immunohistochemical studies, DC participated in its design and coordination, EVT conceived the study and participated in its design and coordination. All authors read and approved the final manuscript.”
“Background For patients with cancer, up to 70% suffered from pain caused by their disease or its treatment [1]. For patients with advanced cancer, pain was described as moderate-severe in approximately 40%-50% and as very severe in 25%-30% [2]. Because pain was an important symptom and occurred frequently in cancer patients, especially for moderate-severe cancer pain, relief of pain should therefore be seen as part of a comprehensive pattern of cancer care. Since the 1980s, treatment of cancer pain was based on the WHO analgesic selleck chemicals llc ladder. Strong opioids were classified at the highest step of the analgesic ladder. But studies

of cancer pain control consistently revealed that up to half of patients received inadequate analgesia and 30% did not receive appropriate drugs for their pain [1]. In China, sustained-release oral morphine and transdermal fentanyl were strong opioids available for the treatment of moderate-severe cancer pain. Fentanyl is a lipid soluble synthetic opioid, which can be delivered in a transdermal controlled systemic new delivery formulation for up to 72 hours. Transdermal fentanyl was accepted to be an effective drug for treating moderate-severe cancer pain. Because it

takes 12-24 hours for serum levels to stabilize after starting the patch or changing the dose, it was less flexible and suitable for patients with unstable pain. However, transdermal fentanyl may reduce the rates of some typical opioid-related adverse effects, particularly constipation [3]. In addition, transdermal fentanyl was conveniently administrated, which simplified the procedure of chronic pain treatment and improved the compliance for using the analgesic. Three systematic reviews of European and American literatures suggested both transdermal fentanyl and sustained-release oral morphine could effectively control moderate-severe cancer pain, but some adverse effects (mainly constipation) check details seemed to favor transdermal opiates in the preference of patients with moderate-severe cancer pain [4–6]. Our previous meta-analysis of 12 Chinese literatures also found similar result [7].