What causes pain in patients with cancer?
A diagnosis of cancer is feared not only because of possible mortality but also due to the morbidity caused by pain and potential loss of functional capacity. Malignancies cause nociceptive effects in the form of visceral, somatic/inflammatory pain, and can also result in neuropathic pain. More than one of these types of cancer-mediated pain may coexist in a patient; in addition, patients with cancer may have pain due to preexisting comorbidities (diabetes, arthritis, migraine), or they may have pain due to treatment effects. Furthermore, nociceptive pain may be amplified by psychological suffering, whereby the experience of pain or discomfort causes additional distress in the form of existential issues such as changes in role, identity, quality of life, and spiritual concerns.