Interventional treatment of cancer pain: the fourth step in the World Health Organization analgesic ladder?

BACKGROUND For most patients with cancer pain, the World Health Organization's three-step analgesic ladder provides adequate management with oral or transdermal options. However, some cancer patients are not well palliated with these approaches. METHODS The author reviews interventional options that include nerve blocks, spinal administration of local anesthetics, opioids, alpha-2 agonists, spinal cord stimulation, and surgical interventions. RESULTS Numerous interventional options are readily accessible and most can be performed on an outpatient basis. They can be used as sole agents for the control of cancer pain or as useful adjuncts to supplement analgesia provided by opioids, thus decreasing opioid dose requirements and side effects. CONCLUSIONS Cancer-related pain can be controlled with several interventions when oral or transdermal opioids are inadequate. A risk:benefit ratio should be considered before implementing invasive analgesic methods.