Factors Influencing Pain Expression in Patients with Cancer: An Expert Opinion.

Pain is a multidimensional experience that requires an appropriate assessment, and simple numbering may not be enough for the different components that are involved in the clinical expression. In consideration of the subjectivity of the symptom, each assessment should start from the way in which the patients perceive the pain and from how they deal with it. Some factors related to individual patient characteristics may make pain management difficult because of interference with the clinical pain expression. These factors may amplify the reporting of pain. Cognitive disorders and psychological distress seem to strongly influence pain expression and may render the analgesic treatment more difficult. Aberrant behaviors, such as alcoholism, smoking, and opioid misuse, may play a role, although geographic differences were found in terms of prevalence of the phenomenon, especially in some countries. Finally, the assessment of patients' expectation and the meaning of the personal feeling of changes in pain intensity provide new concepts in pain assessment, which may allow better personalization of the analgesic therapy. A modern pain assessment should include a multitude of factors influencing the phenotype of pain.