4Cherny N. The management of cancer pain[J]. Cancer Clin, 2000,50 : 70-116.
5Apolone G, Bertetto O, Caraceni A,et al. Pain in cancer. An outcome research project to evaluate the epidemiology, the quality and the effects of pain treatment in cancer patients [J/ OL]. Health and Quality of Outcomes, 2006, 4: 7. http:// www. hqlo. corn/content/4/1/7,2012-12-10.
7Droney J, Ross J, Gretton S, et al. Constipation in cancer pa tients on morphine[J]. Support Care Cancer, 2008,16 (5) :453- 459.
8Caraceni A,Portenoy RK. An international survey of cancer pain characteristics and syndromes [J]. IASP task force on cancer pain. Pain,1999,82(3) :263-274.