HOME

TheInfoList



OR:

Pain in
cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
may arise from a tumor compressing or infiltrating nearby body parts; from treatments and diagnostic procedures; or from skin, nerve and other changes caused by a hormone imbalance or immune response. Most chronic (long-lasting) pain is caused by the illness and most acute (short-term) pain is caused by treatment or diagnostic procedures. However, radiotherapy, surgery and
chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
may produce painful conditions that persist long after treatment has ended. The presence of pain depends mainly on the location of the cancer and the
stage Stage or stages may refer to: Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly British theatre newspaper * Sta ...
of the disease. At any given time, about half of all people diagnosed with
malignant Malignancy () is the tendency of a medical condition to become progressively worse. Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...
cancer are experiencing pain, and two-thirds of those with advanced cancer experience pain of such intensity that it adversely affects their sleep, mood, social relations and activities of daily living. With competent management, cancer pain can be eliminated or well controlled in 80% to 90% of cases, but nearly 50% of cancer patients in the developed world receive less than optimal care. Worldwide, nearly 80% of people with cancer receive little or no pain medication. Cancer pain in children and in people with intellectual disabilities is also reported as being under-treated. Guidelines for the use of drugs in the management of cancer pain have been published by the
World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of ...
(WHO) and others. Healthcare professionals have an ethical obligation to ensure that, whenever possible, the patient or patient's guardian is well-informed about the risks and benefits associated with their
pain management Pain management is an aspect of medicine and health care involving relief of pain (pain relief, analgesia, pain control) in various dimensions, from acute and simple to chronic and challenging. Most physicians and other health professionals pr ...
options. Adequate pain management may sometimes slightly shorten a dying person's life.


Pain

Pain is classed as acute (short term) or chronic (long term). Chronic pain may be continuous with occasional sharp rises in intensity (flares), or intermittent: periods of painlessness interspersed with periods of pain. Despite pain being well controlled by long-acting drugs or other treatment, flares may occasionally be felt; this is called breakthrough pain, and is treated with quick-acting analgesics. The majority of people with chronic pain notice memory and attention difficulties. Objective psychological testing has found problems with memory, attention, verbal ability, mental flexibility and thinking speed. Pain is also associated with increased depression, anxiety, fear, and anger. Persistent pain reduces function and overall quality of life, and is demoralizing and debilitating for the person experiencing pain and for those who care for them. Pain's intensity is distinct from its unpleasantness. For example, it is possible through psychosurgery and some drug treatments, or by suggestion (as in
hypnosis Hypnosis is a human condition involving focused attention (the selective attention/selective inattention hypothesis, SASI), reduced peripheral awareness, and an enhanced capacity to respond to suggestion.In 2015, the American Psychologica ...
and
placebo A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures. In general, placebos can af ...
), to reduce or eliminate the unpleasantness of pain without affecting its intensity. Sometimes, pain caused in one part of the body feels like it is coming from another part of the body. This is called
referred pain Referred pain, also called reflective pain, is pain perceived at a location other than the site of the painful stimulus. An example is the case of angina pectoris brought on by a myocardial infarction (heart attack), where pain is often felt in ...
. Pain in cancer can be produced by mechanical (e.g. pinching) or chemical (e.g. inflammation) stimulation of specialized pain-signalling nerve endings found in most parts of the body (called
nociceptive pain Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, ...
), or it may be caused by diseased, damaged or compressed nerves, in which case it is called
neuropathic pain Neuropathic pain is pain caused by damage or disease affecting the somatosensory system. Neuropathic pain may be associated with abnormal sensations called dysesthesia or pain from normally non-painful stimuli (allodynia). It may have continuous ...
. Neuropathic pain is often accompanied by other feelings such as pins and needles. The patient's own description is the best measure of pain; they will usually be asked to estimate intensity on a scale of 0–10 (with 0 being no pain and 10 being the worst pain they have ever felt). Some patients, however, may be unable to give verbal feedback about their pain. In these cases you must rely on physiological indicators such as facial expressions, body movements, and vocalizations such as moaning.


Cause

About 75 percent of cancer pain is caused by the illness itself; most of the remainder is caused by diagnostic procedures and treatment.


Tumor-related

Tumors cause pain by crushing or infiltrating tissue, triggering infection or inflammation, or releasing chemicals that make normally non-painful stimuli painful. Invasion of bone by cancer is the most common source of cancer pain. It is usually felt as tenderness, with constant background pain and instances of spontaneous or movement-related exacerbation, and is frequently described as severe. Rib fractures are common in breast, prostate and other cancers with rib metastases. The vascular (blood) system can be affected by solid tumors. Between 15 and 25 percent of
deep vein thrombosis Deep vein thrombosis (DVT) is a type of venous thrombosis involving the formation of a blood clot in a deep vein, most commonly in the legs or pelvis. A minority of DVTs occur in the arms. Symptoms can include pain, swelling, redness, and enla ...
is caused by cancer (often by a tumor compressing a vein), and it may be the first hint that cancer is present. It causes swelling and pain in the legs, especially the calf, and (rarely) in the arms. The
superior vena cava The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm) short length vein th ...
(a large vein carrying circulating, de-oxygenated blood into the heart) may be compressed by a tumor, causing superior vena cava syndrome, which can cause chest wall pain among other symptoms. When tumors compress, invade or inflame parts of the nervous system (such as the brain,
spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...
, nerves, ganglia or plexa), they can cause pain and other symptoms. Though brain tissue contains no pain sensors,
brain tumor A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and seconda ...
s can cause pain by pressing on blood vessels or the membrane that encapsulates the brain (the meninges), or indirectly by causing a build-up of fluid ( edema) that may compress pain-sensitive tissue. Pain from cancer of the
organs In biology, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a f ...
, such as the stomach or liver (
visceral pain Visceral pain is pain that results from the activation of nociceptors of the thoracic, pelvic, or abdominal viscera (organs). Visceral structures are highly sensitive to distension (stretch), ischemia and inflammation, but relatively insensitive to ...
), is diffuse and difficult to locate, and is often referred to more distant, usually superficial, sites. Invasion of soft tissue by a tumor can cause pain by inflammatory or mechanical stimulation of pain sensors, or destruction of mobile structures such as ligaments, tendons and skeletal muscles. Pain produced by cancer within the pelvis varies depending on the affected tissue. It may appear at the site of the cancer but it frequently radiates diffusely to the upper thigh, and may refer to the lower back, the external genitalia or
perineum The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), includi ...
.


Diagnostic procedures

Some diagnostic procedures, such as lumbar puncture (see post-dural-puncture headache),
venipuncture In medicine, venipuncture or venepuncture is the process of obtaining intravenous access for the purpose of venous blood sampling (also called ''phlebotomy'') or intravenous therapy. In healthcare, this procedure is performed by medical labor ...
, paracentesis, and
thoracentesis Thoracentesis , also known as thoracocentesis (from Greek ''thōrax'' 'chest, thorax'—GEN ''thōrakos''—and ''kentēsis'' 'pricking, puncture'), pleural tap, needle thoracostomy, or needle decompression (often used term), is an invasive med ...
can be painful.International Association for the Study of Pain
Treatment-Related Pain


Treatment-related

Potentially painful cancer treatments include: *
immunotherapy Immunotherapy or biological therapy is the treatment of disease by activating or suppressing the immune system. Immunotherapies designed to elicit or amplify an immune response are classified as ''activation immunotherapies,'' while immunotherap ...
which may produce joint or muscle pain; *radiotherapy, which can cause skin reactions,
enteritis Enteritis is inflammation of the small intestine. It is most commonly caused by food or drink contaminated with pathogenic microbes,Dugdale, David C., IIII, and George F Longretc"Enteritis" MedlinePlus Medical Encyclopedia, 18 October 2008. Access ...
, fibrosis,
myelopathy Myelopathy describes any neurologic deficit related to the spinal cord. The most common form of myelopathy in humans, ''Spinal cord compression, cervical spondylotic myelopathy (CSM)'', also called ''degenerative cervical myelopathy'', results fro ...
, bone necrosis, neuropathy or plexopathy; *chemotherapy, often associated with chemotherapy induced peripheral neuropathy,
mucositis Mucositis is the painful inflammation and ulceration of the mucous membranes lining the digestive tract, usually as an adverse effect of chemotherapy and radiotherapy treatment for cancer. Mucositis can occur anywhere along the gastrointestina ...
,
joint pain Arthralgia (from Greek ''arthro-'', joint + ''-algos'', pain) literally means ''joint pain''. Specifically, arthralgia is a symptom of injury, infection, illness (in particular arthritis), or an allergic reaction to medication. According to MeSH, ...
,
muscle pain Myalgia (also called muscle pain and muscle ache in layman's terms) is the medical term for muscle pain. Myalgia is a symptom of many diseases. The most common cause of acute myalgia is the overuse of a muscle or group of muscles; another like ...
, and abdominal pain due to diarrhea or constipation; * hormone therapy, which sometimes causes pain flares; * targeted therapies, such as
trastuzumab Trastuzumab, sold under the brand name Herceptin among others, is a monoclonal antibody used to treat breast cancer and stomach cancer. It is specifically used for cancer that is HER2 receptor positive. It may be used by itself or together wi ...
and
rituximab Rituximab, sold under the brand name Rituxan among others, is a monoclonal antibody medication used to treat certain autoimmune diseases and types of cancer. It is used for non-Hodgkin lymphoma, chronic lymphocytic leukemia (in non-geriatric pa ...
, which can cause muscle, joint or chest pain; *
angiogenesis inhibitor An angiogenesis inhibitor is a substance that inhibits the growth of new blood vessels ( angiogenesis). Some angiogenesis inhibitors are endogenous and a normal part of the body's control and others are obtained exogenously through pharmaceutical ...
s like bevacizumab, known to sometimes cause bone pain; *surgery, which may produce post-operative pain, post-amputation pain or pelvic floor myalgia.


Infection

The chemical changes associated with infection of a tumor or its surrounding tissue can cause rapidly escalating pain, but infection is sometimes overlooked as a possible cause. One study found that infection was the cause of pain in four percent of nearly 300 people with cancer who were referred for pain relief. Another report described seven people with cancer, whose previously well-controlled pain escalated significantly over several days. Antibiotic treatment produced pain relief in all of them within three days.


Management

Cancer pain treatment aims to relieve pain with minimal adverse treatment effects, allowing the person a good
quality of life Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards ...
and level of function and a relatively painless death. Though 80–90 percent of cancer pain can be eliminated or well controlled, nearly half of all people with cancer pain in the developed world and more than 80 percent of people with cancer worldwide receive less than optimal care. Cancer changes over time, and pain management needs to reflect this. Several different types of treatment may be required as the disease progresses. Pain managers should clearly explain to the patient the cause of the pain and the various treatment possibilities, and should consider, as well as drug therapy, directly modifying the underlying disease, raising the pain threshold, interrupting, destroying or stimulating pain pathways, and suggesting lifestyle modification. The relief of psychological, social and spiritual distress is a key element in effective pain management.WHO guidelines: * * A person whose pain cannot be well controlled should be referred to a
palliative care Palliative care (derived from the Latin root , or 'to cloak') is an interdisciplinary medical caregiving approach aimed at optimizing quality of life and mitigating suffering among people with serious, complex, and often terminal illnesses. Wit ...
or pain management specialist or clinic.


Psychological


Coping strategies

The way a person responds to pain affects the intensity of their pain (moderately), the degree of disability they experience, and the impact of pain on their
quality of life Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards ...
. Strategies employed by people to cope with cancer pain include enlisting the help of others; persisting with tasks despite pain; distraction; rethinking maladaptive ideas; and prayer or ritual. Some people in pain tend to focus on and exaggerate the pain's threatening meaning, and estimate their own ability to deal with pain as poor. This tendency is termed "catastrophizing". The few studies so far conducted into catastrophizing in cancer pain have suggested that it is associated with higher levels of pain and psychological distress. People with cancer pain who accept that pain will persist and nevertheless are able to engage in a meaningful life were less susceptible to catastrophizing and depression in one study. People with cancer pain who have clear goals, and the motivation and means to achieve those goals, were found in two studies to experience much lower levels of pain, fatigue and depression. People with cancer who are confident in their understanding of their condition and its treatment, and confident in their ability to (a) control their symptoms, (b) collaborate successfully with their informal carers and (c) communicate effectively with health care providers experience better pain outcomes. Physicians should therefore take steps to encourage and facilitate effective communication, and should consider
psychosocial The psychosocial approach looks at individuals in the context of the combined influence that psychological factors and the surrounding social environment have on their physical and mental wellness and their ability to function. This approach is ...
intervention.


Psychosocial interventions

Psychosocial interventions affect the amount of pain experienced and the degree to which it interferes with daily life; and the American Institute of Medicine and the American Pain Society support the inclusion of expert, quality-controlled psychosocial care as part of cancer pain management. Psychosocial interventions include education (addressing among other things the correct use of analgesic medications and effective communication with clinicians) and coping-skills training (changing thoughts, emotions, and behaviors through training in skills such as problem solving, relaxation, distraction and
cognitive restructuring Cognitive restructuring (CR) is a psychotherapeutic process of learning to identify and dispute irrational or maladaptive thoughts known as cognitive distortions,Gladding, Samuel. Counseling: A Comprehensive Review. 6th. Columbus: Pearson Educati ...
). Education may be more helpful to people with stage I cancer and their carers, and coping-skills training may be more helpful at stages II and III. A person's adjustment to cancer depends vitally on the support of their family and other informal carers, but pain can seriously disrupt such interpersonal relationships, so people with cancer and therapists should consider involving family and other informal carers in expert, quality-controlled psychosocial therapeutic interventions.


Medications

The WHO guidelines recommend prompt oral administration of drugs when pain occurs, starting, if the person is not in severe pain, with non-opioid drugs such as paracetamol, dipyrone,
non-steroidal anti-inflammatory drug Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...
s or
COX-2 inhibitor COX-2 inhibitors are a type of nonsteroidal anti-inflammatory drug (NSAID) that directly targets cyclooxygenase-2, COX-2, an enzyme responsible for inflammation and pain. Targeting selectivity for COX-2 reduces the risk of peptic ulceration and i ...
s. Then, if complete pain relief is not achieved or disease progression necessitates more aggressive treatment, mild opioids such as codeine,
dextropropoxyphene Dextropropoxyphene is an analgesic in the opioid category, patented in 1955 and manufactured by Eli Lilly and Company. It is an optical isomer of levopropoxyphene. It is intended to treat mild pain and also has antitussive (cough suppressant) ...
,
dihydrocodeine Dihydrocodeine is a semi-synthetic opioid analgesic prescribed for pain or severe dyspnea, or as an antitussive, either alone or compounded with paracetamol (acetaminophen) (as in co-dydramol) or aspirin. It was developed in Germany in 1908 a ...
or tramadol are added to the existing non-opioid regime. If this is or becomes insufficient, mild opioids are replaced by stronger opioids such as morphine, while continuing the non-opioid therapy, escalating opioid dose until the person is painless or the maximum possible relief without intolerable side effects has been achieved. If the initial presentation is severe cancer pain, this stepping process should be skipped and a strong opioid should be started immediately in combination with a non-opioid analgesic. However, a 2017 Cochrane Review found that there is no high-quality evidence to support or refute the use of non-steroidal anti-inflammatories ( NSAIDs) alone or in combination with opioids for the three steps of the three-step WHO cancer pain ladder and that there is very low-quality evidence that some people with moderate or severe cancer pain can obtain substantial levels of benefit within one or two weeks. Some authors challenge the validity of the second step (mild opioids) and, pointing to their higher toxicity and low efficacy, argue that mild opioids could be replaced by small doses of strong opioids (with the possible exception of tramadol due to its demonstrated efficacy in cancer pain, its specificity for neuropathic pain, and its low sedative properties and reduced potential for respiratory depression in comparison to conventional opioids). More than half of people with advanced cancer and pain will need strong opioids, and these in combination with non-opioid pain medicine can produce acceptable analgesia in 70–90 percent of cases. Morphine is effective in relieving cancer pain although oxycodone shows superior tolerability and anlgesic effect, though cost may limit its value in certain healthcare systems. Side effects of nausea and constipation are rarely severe enough to warrant stopping of treatment. Sedation and cognitive impairment usually occur with the initial dose or a significant increase in dosage of a strong opioid, but improve after a week or two of consistent dosage.
Antiemetic An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of opioid analgesics, general anaesthetics, and chemotherapy directed against cancer. They m ...
and
laxative Laxatives, purgatives, or aperients are substances that loosen stools and increase bowel movements. They are used to treat and prevent constipation. Laxatives vary as to how they work and the side effects they may have. Certain stimulant, lubri ...
treatment should be commenced concurrently with strong opioids, to counteract the usual nausea and constipation. Nausea normally resolves after two or three weeks of treatment but laxatives will need to be aggressively maintained. Buprenorphine is another opioid with some evidence of its efficacy but only low quality evidence comparing it to other opioids. Analgesics should not be taken "on demand" but "by the clock" (every 3–6 hours), with each dose delivered before the preceding dose has worn off, in doses sufficiently high to ensure continuous pain relief. People taking slow-release morphine should also be provided with immediate-release ("rescue") morphine to use as necessary, for pain spikes (
breakthrough pain Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, ...
) that are not suppressed by the regular medication. Oral analgesia is the cheapest and simplest mode of delivery. Other delivery routes such as sublingual, topical, transdermal, parenteral, rectal or spinal should be considered if the need is urgent, or in case of vomiting, impaired swallow, obstruction of the gastrointestinal tract, poor absorption or coma. Current evidence for the effectiveness of
fentanyl Fentanyl, also spelled fentanil, is a very potent synthetic opioid used as a pain medication. Together with other drugs, fentanyl is used for anesthesia. It is also used illicitly as a recreational drug, sometimes mixed with heroin, cocain ...
transdermal patch A transdermal patch is a medicated adhesive patch that is placed on the skin to deliver a specific dose of medication through the skin and into the bloodstream. An advantage of a transdermal drug delivery route over other types of medica ...
es in controlling chronic cancer pain is weak but they may reduce complaints of constipation compared with oral morphine. Liver and kidney disease can affect the biological activity of analgesics. When people with diminishing liver or kidney function are treated with oral opioids they must be monitored for the possible need to reduce dose, extend dosing intervals, or switch to other opioids or other modes of delivery. The benefit of non-steroidal anti-inflammatory drugs should be weighed against their gastrointestinal, cardiovascular, and renal risks. Not all pain yields completely to classic analgesics, and drugs that are not traditionally considered analgesics but which reduce pain in some cases, such as steroids or
bisphosphonates Bisphosphonates are a class of drugs that prevent the loss of bone density, used to treat osteoporosis and similar diseases. They are the most commonly prescribed drugs used to treat osteoporosis. They are called bisphosphonates because they ...
, may be employed concurrently with analgesics at any stage.
Tricyclic antidepressants Tricyclic antidepressants (TCAs) are a class of medications that are used primarily as antidepressants, which is important for the management of depression. They are second-line drugs next to SSRIs. TCAs were discovered in the early 1950s and wer ...
, class I antiarrhythmics, or anticonvulsants are the drugs of choice for neuropathic pain. Such adjuvants are a common part of palliative care and are used by up to 90 percent of people with cancer as they approach death. Many adjuvants carry a significant risk of serious complications. Anxiety reduction can reduce the unpleasantness of pain but is least effective for moderate and severe pain. Since
anxiolytic An anxiolytic (; also antipanic or antianxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxiet ...
s such as benzodiazepines and major
tranquilizer A tranquilizer is a drug that is designed for the treatment of anxiety, fear, tension, agitation, and disturbances of the mind, specifically to reduce states of anxiety and tension. Etymology Tranquilizer, as a term, was first used by F.F. Yonk ...
s add to sedation, they should only be used to address anxiety, depression, disturbed sleep or muscle spasm.


Interventional

If the analgesic and adjuvant regimen recommended above does not adequately relieve pain, additional options are available.


Radiation

Radiotherapy is used when drug treatment is failing to control the pain of a growing tumor, such as in bone metastasis (most commonly), penetration of soft tissue, or compression of sensory nerves. Often, low doses are adequate to produce analgesia, thought to be due to reduction in pressure or, possibly, interference with the tumor's production of pain-promoting chemicals.
Radiopharmaceutical Radiopharmaceuticals, or medicinal radiocompounds, are a group of pharmaceutical drugs containing radioactive isotopes. Radiopharmaceuticals can be used as diagnostic and therapeutic agents. Radiopharmaceuticals emit radiation themselves, which ...
s that target specific tumors have been used to treat the pain of metastatic illnesses. Relief may occur within a week of treatment and may last from two to four months.


Neurolytic block

A
neurolytic block Nerve block or regional nerve blockade is any deliberate interruption of signals traveling along a nerve, often for the purpose of pain relief. Local anesthetic nerve block (sometimes referred to as simply "nerve block") is a short-term block, u ...
is the deliberate injury of a nerve by the application of chemicals (in which case the procedure is called "
neurolysis Neurolysis is the application of physical or chemical agents to a nerve in order to cause a temporary degeneration of targeted nerve fibers. When the nerve fibers degenerate, it causes an interruption in the transmission of nerve signals. In the med ...
") or physical agents such as freezing or heating ("
neurotomy Neurotomy may refer to the application of heat (as in radio frequency nerve lesioning) or freezing to sensory nerve fibers to cause their temporary degeneration, usually to relieve pain. Neurotomy and neurolysis (where the degeneration is caused by ...
"). These interventions cause degeneration of the nerve's fibers and temporary interference with the transmission of pain signals. In these procedures, the thin protective layer around the nerve fiber, the basal lamina, is preserved so that, as a damaged fiber regrows, it travels within its basal lamina tube and connects with the correct loose end, and function may be restored. Surgically cutting a nerve severs these basal lamina tubes, and without them to channel the regrowing fibers to their lost connections, a painful neuroma or
deafferentation pain Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or or ...
may develop. This is why the neurolytic is preferred over the surgical block. A brief "rehearsal" block using local anesthetic should be tried before the actual neurolytic block, to determine efficacy and detect side effects. The aim of this treatment is pain elimination, or the reduction of pain to the point where opioids may be effective. Though the neurolytic block lacks long-term outcome studies and evidence-based guidelines for its use, for people with progressive cancer and otherwise incurable pain, it can play an essential role.


Cutting or destruction of nervous tissue

Surgical cutting or destruction of peripheral or central nervous tissue is now rarely used in the treatment of pain. Procedures include neurectomy, cordotomy, dorsal root entry zone lesioning, and cingulotomy. Cutting through or removal of nerves (
neurectomy A neurectomy is a type of nerve block involving the severing or removal of a nerve. This surgery is performed in rare cases of severe chronic pain where no other treatments have been successful, and for other conditions such as vertigo, involuntary ...
) is used in people with cancer pain who have short life expectancy and who are unsuitable for drug therapy due to ineffectiveness or intolerance. Because nerves often carry both sensory and motor fibers, motor impairment is a possible side effect of neurectomy. A common result of this procedure is "deafferentation pain" where, 6–9 months after surgery, pain returns at greater intensity. Cordotomy involves cutting nerve fibers that run up the front/side (anterolateral) quadrant of the spinal cord, carrying heat and pain signals to the brain. Pancoast tumor pain has been effectively treated with dorsal root entry zone lesioning (destruction of a region of the spinal cord where peripheral pain signals cross to spinal cord fibers); this is major surgery that carries the risk of significant neurological side effects.
Cingulotomy Bilateral cingulotomy is a form of psychosurgery, introduced in 1948 as an alternative to lobotomy. Today, it is mainly used in the treatment of depression and obsessive-compulsive disorder. In the early years of the twenty-first century, it was ...
involves cutting nerve fibers in the brain. It reduces the unpleasantness of pain (without affecting its intensity), but may have cognitive side effects.


Hypophysectomy

Hypophysectomy is the destruction of the
pituitary gland In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The ...
, and has reduced pain in some cases of metastatic breast and prostate cancer pain.


Patient-controlled analgesia

;Intrathecal pump :An external or implantable
intrathecal pump An intrathecal pump is a medical device used to deliver (via an intrathecal catheter) medications directly into the space between the spinal cord and the protective sheath surrounding the spinal cord. Medications such as baclofen, bupivacaine, clo ...
infuses a
local anesthetic A local anesthetic (LA) is a medication that causes absence of pain sensation. In the context of surgery, a local anesthetic creates an absence of pain in a specific location of the body without a loss of consciousness, as opposed to a general a ...
such as
bupivacaine Bupivacaine, marketed under the brand name Marcaine among others, is a medication used to decrease feeling in a specific area. In nerve blocks, it is injected around a nerve that supplies the area, or into the spinal canal's epidural space. I ...
and/or an
opioid Opioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioid use ...
such as
morphine Morphine is a strong opiate that is found naturally in opium, a dark brown resin in poppies (''Papaver somniferum''). It is mainly used as a pain medication, and is also commonly used recreationally, or to make other illicit opioids. T ...
and/or
ziconotide Ziconotide (SNX–111; Prialt), also called intrathecal ziconotide (ITZ) because of its administration route, is an atypical analgesic agent for the amelioration of severe and chronic pain. Derived from ''Conus magus'', a cone snail, it is the ...
and/or some other nonopioid analgesic as clonidine (currently only morphine and ziconotide are the only agents approved by the
US Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...
for IT analgesia) directly into the fluid-filled space (the
subarachnoid cavity In anatomy, the meninges (, ''singular:'' meninx ( or ), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in th ...
) between the
spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...
and its protective sheath, providing enhanced analgesia with reduced systemic
side effect In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
s. This can reduce the level of pain in otherwise intractable cases. ;Long-term epidural catheter :The outer layer of the sheath surrounding the spinal cord is called the
dura mater In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. ...
. Between this and the surrounding
vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristi ...
e is the
epidural space In anatomy, the epidural space is the potential space between the dura mater and vertebrae (spine). The anatomy term "epidural space" has its origin in the Ancient Greek language; , "on, upon" + dura mater also known as "epidural cavity", "e ...
filled with connective tissue, fat and blood vessels and crossed by the spinal nerve roots. A long-term epidural catheter may be inserted into this space for three to six months, to deliver anesthetics or analgesics. The line carrying the drug may be threaded under the skin to emerge at the front of the person, a process called "tunneling", recommended with long-term use to reduce the chance of any infection at the exit site reaching the epidural space.


Spinal cord stimulation

Electrical stimulation of the dorsal columns of the spinal cord can produce analgesia. First, the leads are implanted, guided by
fluoroscopy Fluoroscopy () is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope () allows a physician to see the internal structure and function ...
and feedback from the patient, and the generator is worn externally for several days to assess efficacy. If pain is reduced by more than half, the therapy is deemed to be suitable. A small pocket is cut into the tissue beneath the skin of the upper buttocks, chest wall or abdomen and the leads are threaded under the skin from the stimulation site to the pocket, where they are attached to the snugly fitting generator. It seems to be more helpful with neuropathic and
ischemic Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems w ...
pain than nociceptive pain, but current evidence is too weak to recommend its use in the treatment of cancer pain.


Complementary and alternative medicine

Due to the poor quality of most studies of
complementary and alternative medicine Alternative medicine is any practice that aims to achieve the healing effects of medicine despite lacking biological plausibility, testability, repeatability, or evidence from clinical trials. Complementary medicine (CM), complementary and al ...
in the treatment of cancer pain, it is not possible to recommend integration of these therapies into the management of cancer pain. There is weak evidence for a modest benefit from hypnosis; studies of massage therapy produced mixed results and none found pain relief after 4 weeks; Reiki, and touch therapy results were inconclusive; acupuncture, the most studied such treatment, has demonstrated no benefit as an adjunct analgesic in cancer pain; the evidence for music therapy is equivocal; and some herbal interventions such as PC-SPES, mistletoe, and saw palmetto are known to be toxic to some people with cancer. The most promising evidence, though still weak, is for mind-body interventions such as biofeedback and relaxation techniques.


Barriers to treatment

Despite the publication and ready availability of simple and effective evidence-based pain management guidelines by the
World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of ...
(WHO) and others,Other clinical guidelines: * * * * * many medical care providers have a poor understanding of key aspects of pain management, including assessment,
dosing Dosing generally applies to feeding chemicals or medicines when used in small quantities. For medicines the term '' dose'' is generally used. In the case of inanimate objects the word dosing is typical. The term dose titration, referring to stepw ...
, tolerance,
addiction Addiction is a neuropsychological disorder characterized by a persistent and intense urge to engage in certain behaviors, one of which is the usage of a drug, despite substantial harm and other negative consequences. Repetitive drug use o ...
, and
side effects In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
, and many do not know that pain can be well controlled in most cases. In Canada, for instance,
veterinarian A veterinarian (vet), also known as a veterinary surgeon or veterinary physician, is a medical professional who practices veterinary medicine. They manage a wide range of health conditions and injuries in non-human animals. Along with this, vet ...
s get five times more training in pain than do physicians, and three times more training than nurses. Physicians may also undertreat pain out of fear of being audited by a regulatory body. Systemic institutional problems in the delivery of pain management include lack of resources for adequate training of physicians, time constraints, failure to refer people for pain management in the clinical setting, inadequate insurance reimbursement for pain management, lack of sufficient stocks of pain medicines in poorer areas, outdated government policies on cancer pain management, and excessively complex or restrictive government and institutional regulations on the prescription, supply, and administration of opioid medications. People with cancer may not report pain due to costs of treatment, a belief that pain is inevitable, an aversion to treatment side effects, fear of developing addiction or tolerance, fear of distracting the doctor from treating the illness, or fear of masking a symptom that is important for monitoring progress of the illness. People may be reluctant to take adequate pain medicine because they are unaware of their prognosis, or may be unwilling to accept their diagnosis. Failure to report pain or misguided reluctance to take pain medicine can be overcome by sensitive coaching.


Epidemiology

Pain is experienced by 53 percent of all people diagnosed with malignant cancer, 59 percent of people receiving anticancer treatment, 64 percent of people with metastatic or advanced-stage disease, and 33 percent of people after completion of curative treatment. Evidence for prevalence of pain in newly diagnosed cancer is scarce. One study found pain in 38 percent of people who were newly diagnosed, another found 35 percent of such people had experienced pain in the preceding two weeks, while another reported that pain was an early symptom in 18–49 percent of cases. More than one third of people with cancer pain describe the pain as moderate or severe. Primary tumors in the following locations are associated with a relatively high prevalence of pain: *
Head and neck This article describes the anatomy of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat. Structure Bones The head rests on the top part of the vertebra ...
(67 to 91 percent) *
Prostate The prostate is both an accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found only in some mammals. It differs between species anatomically, chemically, and phys ...
(56 to 94 percent) *
Uterus The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...
(30 to 90 percent) * The genitourinary system (58 to 90 percent) *
Breast The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues. In females, it serves as the mammary gland, which produces and sec ...
(40 to 89 percent) *
Pancreas The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an en ...
(72 to 85 percent) *
Esophagus The esophagus ( American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to ...
(56 to 94 percent) All people with advanced multiple myeloma or advanced
sarcoma A sarcoma is a malignant tumor, a type of cancer that arises from transformed cells of mesenchymal ( connective tissue) origin. Connective tissue is a broad term that includes bone, cartilage, fat, vascular, or hematopoietic tissues, and sar ...
are likely to experience pain.


Legal and ethical considerations

The
International Covenant on Economic, Social and Cultural Rights The International Covenant on Economic, Social and Cultural Rights (ICESCR) is a multilateral treaty adopted by the United Nations General Assembly (GA) on 16 December 1966 through GA. Resolution 2200A (XXI), and came in force from 3 January 197 ...
obliges signatory nations to make pain treatment available to those within their borders as a duty under the human
right to health The right to health is the economic, social, and cultural right to a universal minimum standard of health to which all individuals are entitled. The concept of a right to health has been enumerated in international agreements which include the U ...
. A failure to take reasonable measures to relieve the suffering of those in pain may be seen as failure to protect against inhumane and degrading treatment under Article 5 of the
Universal Declaration of Human Rights The Universal Declaration of Human Rights (UDHR) is an international document adopted by the United Nations General Assembly that enshrines the rights and freedoms of all human beings. Drafted by a UN committee chaired by Eleanor Roosevelt, ...
. The right to adequate palliative care has been affirmed by the US Supreme Court in two cases, '' Vacco v. Quill'' and '' Washington v. Glucksberg'', which were decided in 1997. This right has also been confirmed in statutory law, such as in the California Business and Professional Code 22, and in other case law precedents in circuit courts and in other reviewing courts in the US. The 1994 Medical Treatment Act of the
Australian Capital Territory The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding townships. I ...
states that a "patient under the care of a health professional has a right to receive relief from pain and suffering to the maximum extent that is reasonable in the circumstances". Patients and their guardians must be apprised of any serious risks and the common side effects of pain treatments. What appears to be an obviously acceptable risk or harm to a professional may be unacceptable to the person who has to undertake that risk or experience the side effect. For instance, people who experience pain on movement may be willing to forgo strong opioids in order to enjoy alertness during their painless periods, whereas others would choose around-the-clock sedation so as to remain pain-free. The care provider should not insist on treatment that someone rejects, and must not provide treatment that the provider believes is more harmful or riskier than the possible benefits can justify. Some patients – particularly those who are terminally ill – may not wish to be involved in making pain management decisions, and may delegate such choices to their treatment providers. The patient's participation in his or her treatment is a right, not an obligation, and although reduced involvement may result in less-than-optimal pain management, such choices should be respected. As medical professionals become better informed about the interdependent relationship between physical, emotional, social, and spiritual pain, and the demonstrated benefit to physical pain from alleviation of these other forms of suffering, they may be inclined to question the patient and family about interpersonal relationships. Unless the person has asked for such psychosocial intervention – or at least freely consented to such questioning – this would be an ethically unjustifiable intrusion into the patient's personal affairs (analogous to providing drugs without the patient's informed consent). The obligation of a professional medical care provider to alleviate suffering may occasionally come into conflict with the obligation to prolong life. If a terminally ill person prefers to be painless, despite a high level of sedation and a risk of shortening their life, they should be provided with their desired pain relief (despite the cost of sedation and a possibly slightly shorter life). Where a person is unable to be involved in this type of decision, the law and the medical profession in the United Kingdom allow the doctor to ''assume'' that the person would prefer to be painless, and thus the provider may prescribe and administer adequate analgesia, even if the treatment may slightly hasten death. It is taken that the underlying cause of death in this case is the illness and not the necessary pain management. One philosophical justification for this approach is the doctrine of double effect, where to justify an act involving both a good and a bad effect, four conditions are necessary: * the act must be good overall (or at least morally neutral) * the person acting must intend only the good effect, with the bad effect considered an unwanted side effect * the bad effect must not be the cause of the good effect * the good effect must outweigh the bad effect.


References


Further reading

* {{Medical resources , ICD10 = {{ICD10, G89.3 , ICD9 = , ICDO = , OMIM = , DiseasesDB = , MedlinePlus = , eMedicineSubj = , eMedicineTopic = , MeSH = , GeneReviewsNBK = , GeneReviewsName = , NORD = , GARDNum = , GARDName = , Orphanet = , Monarch = Oncology Pain