New developments in the assessment of pain in cancer patients.

Pain occurs in more than 80% of cancer patients before death. During recent years major progress has taken place in our techniques for the adequate assessment of cancer pain. Major prognostic factors associated with the pain syndrome have been recognized. In addition, other prognostic factors associated with the characteristics of the patient have been defined. Valid tools have been developed that allow for the assessment of most of the prognostic variables associated with analgesic response. During recent years a major effort has been made to integrate the pain syndrome within the other complex symptoms that are often present in patients with advanced cancer. The interaction of pain and analgesic treatment with other symptoms and their management is discussed. Finally, areas where future research should focus in the area of the diagnosis and assessment of pain are discussed.