When pain is invisible: the importance of detecting neuropathic pain in cancer patients

Abstract

Pain is an unpleasant sensory and emotional experience classified by its duration (acute or chronic), pathophysiology (nociceptive, neuropathic, or mixed), and location (somatic or visceral). Its pathophysiology begins with the activation of peripheral nociceptors that transmit signals to the spinal cord and then to the brain, where pain is perceived. Descending modulatory systems inhibit pain transmission through neurotransmitters like serotonin and norepinephrine. In cancer, neuropathic pain arises from nerve damage caused by tumors, surgery, chemotherapy, or radiation, manifesting as burning, tingling, or electric shocks. Its management requires a multimodal approach with opioids, antidepressants, anticonvulsants, and adjuvant therapies to improve patient quality of life.