Cancer-Related Neuropathic Pain: Mechanism and Therapy.

Pain is usually elicited by the activation of specific visceral or non-visceral (somatic) nociceptors ('nociceptive pain'). However, it may also result from injury to or dysfunction of peripheral sensory nerve fibers or from damage to or dysfunction of the central nervous system itself ('neuropathic pain'). Although acute nociceptive pain fulfills a warning role regarding possible systemic injury, chronic and/or neuropathic pain may be maladaptive. Cancer-related neuropathic pain generally results from compression irritation, or infiltration of nerves by the tumor, nerve trauma from operative procedures, or neuropathic pain related to the treatment of cancer itself. Management of neuropathic pain may include the use of opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), antidepressants, anticonvulsants, local anesthetics, and other adjuvant medications. Intractable neuropathic pain may require the use of intraspinal delivery of medication or anesthetic and neurosurgical procedures. The purpose of this article is to provide a global account of the mechanisms involved in the development of neuropathic pain. Particular attention is focused on cellular aspects and on the consequences of peripheral nervous system (PNS) injury. Further, therapies used for the management of cancer related neuropathic pain are reviewed; new therapeutic approaches based on recent findings from basic research are discussed. An improved understanding of the origins of neuropathic pain should facilitate the development of novel strategies for effective treatment of cancer-related neuropathic pain. [ABSTRACT FROM PUBLISHER]