Talk:Cancer pain/Sources

Cancer pain	Source	Citation
Pain in cancer may be caused by the tumor itself or by medical interventions in the diagnosis and treatment of the disease.
Approximately half of all cancer patients have pain,	About half of cancer patients experience pain	Marcus2011:Marcus DA. Epidemiology of cancer pain. Curr Pain Headache Rep. 2011;15(4):231–4. doi:10.1007/s11916-011-0208-0. PMID 21556709.
and about a third of cancer patients with pain experience moderate or severe pain that often diminishes their enjoyment of life and interferes with sleep and daily activities.	Moderate or severe pain, which is estimated to occur in one third of patients with cancer who experience pain, is often associated with interference with sleep, daily life activities, enjoyment of life, work ability, and social interactions.	Gorin: Sheinfeld Gorin S, Krebs P, Badr H; et al. (2012). "Meta-analysis of psychosocial interventions to reduce pain in patients with cancer". J. Clin. Oncol. 30 (5): 539–47. doi:10.1200/JCO.2011.37.0437. PMID 22253460. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
Pain is more common in the later stages of the disease. Treatment and diagnostic interventions may cause acute (transitory) pain, and chronic (long-term) pain may be caused by either treatment or the disease itself. Radiotherapy and chemotherapy are examples of treatments that can sometimes produce significant pain persisting long after the disease has been cured. Tumors can cause pain by activating specialised pain sensitive nerve fibers (nociceptors), by irritating or damaging somatosensory nerves (or other parts of the somatosensory system), or by releasing chemicals that make nociceptors responsive to normally non-painful stimuli. Cancer pain can be eliminated or well controlled in 80–90 percent of cases by the use of drugs and other interventions, but nearly one in two patients receives less-than-optimal care. Best-practice guidelines for the use of drugs in the management of cancer pain have been published by the World Health Organisation and national and international medical organisations. Health care professionals have an ethical obligation to ensure that, wherever possible, their patients are well informed about the risks and benefits associated with their pain management options. Adequate pain management may sometimes slightly shorten a dying patient's life.
The majority of patients with chronic pain report memory and attention difficulties. Neuropsychological testing has found deficits in memory, attention, cognitive processing speed, verbal ability, and mental flexibility	Most patients with chronic pain complain of cognitive difficulties, mainly with respect to memory and attention. Objective cognitive deficits are mainly in the domains of memory, attention, speed in performing structured tasks, speed in responding to stimuli of a cognitive task, verbal ability, and mental flexibility.	Kreitler S & Niv D. Cognitive impairment in chronic pain. Pain clinical updates. July 2007;XV(4).
and pain is associated with increased depression, anxiety, fear, and anger.	For more than 60 years, the experience of pain has been reported to be associated with various negative emotional states, including depression, anxiety, fear, and anger	Bruehl S, Burns JW, Chung OY, Chont M. Pain-related effects of trait anger expression: neural substrates and the role of endogenous opioid mechanisms. Neurosci Biobehav Rev. 2009;33(3):475–91. doi:10.1016/j.neubiorev.2008.12.003. PMID 19146872.
Persistent pain reduces function and overall quality of life, and is demoralizing and debilitating for both patients and those who care for them.	Persistent pain decreases function, appetite, and sleep, induces fear, causes depression, and generally lowers the quality of life.2 Persistent pain is demoralizing and debilitating for patients and their caregivers.3	Induru RR, Lagman RL. Managing cancer pain: frequently asked questions. Cleve Clin J Med. 2011;78(7):449–64. doi:10.3949/ccjm.78a.10054. PMID 21724928.
The sensation of pain is distinct from its unpleasantness. For example, it is possible in some cases, through psychosurgery or drug treatment, to remove the unpleasantness from pain without affecting its intensity, and suggestion, as in hypnosis and placebo, can also sometimes temporarily reduce pain's unpleasantness while leaving its intensity unchanged. Some drug therapies and other interventions can remove both the sensation of pain and its unpleasantness, and certain emotional states, such as the excitement of sport or war, can produce the same effect.		Melzack R&Casey KL. Sensory, motivational and central control determinants of chronic pain: A new conceptual model. In: Kenshalo DR. The skin senses: Proceedings of the first International Symposium on the Skin Senses, held at the Florida State University in Tallahassee, Florida. Springfield: Charles C. Thomas; 1968. p. 423–443.
Cancer pain is classed as acute (short term), which may be caused by medical investigation or treatment, or chronic (long-lasting).	Cancer pain syndromes can be either acute or chronic. Diagnostic and therapeutic interventions are primarily responsible for the acute pain syndromes.	Portenoy RK; Conn M (23 June 2003). "Cancer pain syndromes". In Bruera ED & Portenoy RK (ed.). Cancer Pain: Assessment and Management. Cambridge University Press. p. 8. ISBN 978-0-521-77332-4.