The word cancer itself brings in the mind of a commoner a painful death. One fact is definite, by the time patient starts seeking help for pain relief, his fear of death from cancer would have disappeared. Pain is experienced by at least 75% of those with advanced disease and, by 20% to 25% at the time of diagnosis. One bright aspect about cancer related pain is that nearly 80 to 90% of pain can be relieved by pharmacological methods like analgesics and other related drugs. Some patients will require supplemental chemotherapy or radiotherapy. The optimum control of cancer pain has been a difficult and a challenging goal for physicians. Many modalities have been employed in attempts to control or palliate the suffering. These include medications, physiotherapy, psychotherapy, hypnosis, acupuncture apart from the anticancer therapy optimization to control the disease so also relieve the pain.
The reason for pain in cancer patient could be because of 2:
Cancer related Progression
Cancer related Progression of disease and infiltration of other structures in the body. They are like
» Soft tissue infiltration
- Infiltration of plexus or nerve roots or peripheral nerves
- Infiltration of bone
Pain secondary to treatment like post-surgical, post-radiotherapy or post-chemotherapy.
» Post-mastectomy lymphoedema
» Post-thoracotomy intercostal neuralgia
» Phantom limb pain
b) Post-radiation syndrome
» Radiation fibrosis of nerves
» Radiation fibrosis of other structures
» Post-chemotherapy--peripheral neuropathy
» Steroid side effects n Headache
» Bed sores
» Bone fractures
» Nerve compression
» Osteoporosis (loss of calcium matrix)
» Osteoarthritis (age related degenerative changes)
» Postherpetic neuralgia
No cause that can be immediately established
Cancer pain has both nociceptive and neuropathic components. Nociceptive or somatic pain results from direct stimulation of nociceptive, intact afferent nerve endings. This type of pain is usually described as 'dull', 'sharp' or 'aching' or a combination of these and the intensity of the pain vary from mild to severe. In general, somatic pain can be well controlled if the cause of the stimulation can be removed, or treated, for example, with surgery, chemotherapy or analgesics. Neuropathic pain, on the other hand, is caused by nervous system dysfunction, rather than stimulation of intact afferent nerve ending. 'Burning', 'shooting', and 'tingling pain' characterize it. The most frequent causes of neuropathic pain in cancer patients are tumour or treatment related nerve damage, acute herpes zoster, postherpetic neuralgia and phantom limb pain. Compared with nociceptive pain, neuropathic pain usually requires more complex pharmacotherapy.