[Prevalence and characteristics of neuropathic pain in malignant disease.].

Neuropathic pain is one of the problem areas in the management of cancer pain. In a retrospective study, prevalence and characteristics of neuropathic pain in 1318 cancer patients attending a pain clinic were examined. Of the patients, 135 suffered from neuropathic, 285 from neuropathic and nociceptive, 890 from nociceptive and 8 from unknown pain conditions. Among the patients with neuropathic pain 62% rated the pain intensity as very sincere; this was so in 48% of those with nociceptive pain. Neuropathic pain was caused by direct tumour involvement (nerve compression or infiltration) in 71%, by oncological treatment (surgery, chemotherapy, radiation) in 15%, by debilitating disease (e.g. herpes zoster) in 6% and by factors unrelated to cancer or its treatment in 8% of the patients. Of 110 clinically analysed neuropathic pain conditions, 44% were neuralgic, 31% radicular, 13% sympathically maintained, and 10% caused by deafferentiation, while in 3% the nature was unknown. To evaluate the efficacy of cancer pain treatment, nocicepetive pain has to be differentiated from neuropathic pain. In addition to this, neuropathic pain has to be divided into subgroups.