For most people experiencing pain related to cancer or its treatment, opioid medications are successful in relieving it. If pain persists or worsens in spite of other treatments, however, your doctor may recommend a nerve-blocking technique that can stop pain signals from going through the nerves. Nerve-blocking techniques also may be used in cases of advanced breast cancer that is causing persistent pain.
A nerve block involves injecting a local anesthetic (numbing medication, such as lidocaine or bupivacaine) into or around a nerve, or into the space around the spinal cord, to block pain signals before they can travel to the brain. Sometimes the medication may be combined with a steroid. Or, for longer-lasting pain relief, a substance such as alcohol or phenol may be injected. Never blocks can last for several months at a time, but they do have to be repeated. Possible side effects include:
- pain at the injection site
- temporary muscle paralysis
- loss of all feeling in the affected area
- very low blood pressure (hypotension)
- kidney damage
- weakness in the legs
Spinal analgesia involves injecting an opioid pain medication such as morphine directly into the fluid around the spine (called intrathecal injection) or into the space around the layers of the spine (called an epidural). Sometimes an anesthetic (numbing) medication may be used as well. Some people undergo minor surgery to implant a pump and a tube that can be used to deliver the pain medicine directly into the spinal area. Spinal analgesia can cause some of the same side effects as opioids taken by mouth, although the side effects generally are less severe. They may include:
If all other methods of pain control do not provide relief, it is possible to have surgery to interrupt the nerve pathways that carry pain impulses to the brain. A neurosurgeon with special expertise in pain management can cut some of the nerves near the spinal cord, putting an end to any sensations of pain and pressure. Again, this is usually only done if no other pain interventions provide adequate relief.