Cancer is a universal health issue. World Health Organization statistics show that 9 million people die per year. Reports have shown that 6,7 million people lost their lives because of new cancer diagnosis and cancer. It has also been reported that the number of cancer patients with a maximum of 3 years of diagnosis is 24,6 million. Cancer pain may be due to the disease or may be caused by various treatment approaches
Pain can occur early in 30-45% of cancer patients, but it can be confronted as a problem in 75% of late-stage patients. While the severity of these pain is 40-50% moderate to severe in the patient, 25-30% of the patients have severe and unbearable pain.
Even today, even in the presence of multimodal treatment methods, 46% of patients do not receive adequate pain treatment at the time of death. For this reason, the World Health Organization has defined the cancer pain as a personal right and has emphasized that this pain must be eliminated.
The development and severity of pain may be different according to the type of cancer.
Table 1: Relationship between cancer types and pain
Cancer type Pain rate (%)
Oral cavity 80
Genitourinary (Male-Female) 75-78
Gastrointestinal tract 40
70% of cancer pain is pain caused by the disease.
Table 2: Causes of cancer-related pain in cancer patients
Pressure on nerve roots and plexus,
Infiltration of nerve tissue to the tumor
Vascular infiltration and blockage,
Infiltration of fascia, perioste and other pain sensitive structures
Infection and inflammation of mucous membranes and other pain sensitive structures
25% of the pain can be caused by some approaches used in cancer treatment.
Table 3: Cancer causes of non-cancer pain
• Surgical pain
• Acute postoperative pain
• Chronic pain (pain after mastectomy, pain after thoracotomy, phantom pain, pain due to lymphedema)
• Chemotherapy-induced pain
• Acute (gastrointestinal, mucositis, myalgia, joint aches, cardiomyopathy, pancreatitis and pain resulting from extravasation)
• Chronic (peripheral neuropathy, steroid pseudoromatism, aseptic bone necrosis and postherpetic neuralgia)
• Pain due to radiotherapy
• Acute (skin burns, gastrointestinal aches, proctitis, mucositis, resulting pain)
• Chronic (eg osteonecrosis, radiation fibrosis, keratitis, demyelination, pneumonia, intestinal ulceration and obstruction, pain associated with myelopathies)
In various studies, 50-80% of patients who have cancer pain are focusing on the inadequacy of treatment for pain. However, with simple pharmacological methods, it is possible to achieve success in 90% of patients who have cancer pain.
Cancer pain can be nociceptive or neuropathic.
Pain in nociceptive character is the nerve conduction, whereas pain in the neuropathic character is the frontal plane in the patients in which the nervous system is affected.
Nociceptive pain is well localized when originated from superinervated superficial regions and called somatic pain.
Visceral pain is caused by diffuse organs that are invisible and can not be localized well.
Direct compression of the neuropathic pain leading to the nerve, may be due to tumor invasion of the nerves, chemotherapy, viral infections or surgical trauma.
Apart from the physical characteristics of cancer pain, psychological and social consequences also affect the quality of life of the patient.
For this reason, control of psychological and social influences during the treatment phase is also important. Evaluation and re-evaluation are of great importance in the treatment of cancer pain.
This is important both in the follow-up of the efficacy or inadequacy of the treatment, and in the recognition of different localizations and pain in the character that arise as the disease progresses.
Therapeutic pharmacological approaches, physical methods, neurolytic blocks, cognitive and behavioral approaches, and intraspinal analgesics and co-analgesics can be used.
There are also some obstacles to the appropriate approach to cancer pain. The first of these is the fear of drug addiction in the patient.
In this regard, physicians also manifest themselves as confusing psychological and physical dependence, ignorance of pharmacological tolerance and exaggerated side effects. Prophylactic and inadequate therapeutic approaches to opioid side effects such as constipation do not result in appropriate analgesic treatment approaches in cancer patients.
Adherence to ongoing treatment protocols and the lack of routine cancer pain assessment are also factors that reduce treatment efficacy.
Patient evaluation should be carried out in cooperation with the patient, family and health personnel. When the treatment method is determined,
. it is of great importance to make the decision with the patient and the family,
. to provide the active participation of the treatment patient,
. to inform the patient about the side effects,
. to take the opinions of the relevant departments with an interdisciplinary approach to pain
Psychosocial assessment should be done alongside detailed history and physical examination on clinical evaluation.
Assessment of pain is also a difficult symptom in cancer patients because it is a subjective symptom. The location of the pain, the severity, the character, the increasing and decreasing factors, the behavioral responses and the treatment targets should be determined.
In the treatment of pain, the World Health Organization's 1986 step pain treatment recommendation is accepted all over the world and can be modified from center to center and from country to country according to small approach differences (Figure 1).
Figure 1: World Health Organization recommends three-step pain therapy
• Diclofenac (long acting)
Weak opioids and combinations that can be used in the second step:
• Codeine + Acetaminophen
• Kodein + ASA
The agents used in the third step are strong opioids. The most common of these is morphology. Morphine has no ceiling effect like nonsteroidal anti-inflammatory drugs and there is no upper dose limit in treatment. Fentanyl transdermal form is also an opioid that may be preferred due to its ease of use. Opioid rotation, especially at higher doses, may allow the use of lower equivalent doses. Meperidine should not be used in patients with chronic cancer pain due to short duration of action and normeperidine in the neurotoxic metabolite.
Opioids can be applied in different ways. These:
• Transdermal fentanyl
• Intermittent injection
• Continuous infusion
• Patient controlled analgesia
The most frequent side effects that can be seen with opioids are constipation, nausea, vomiting, dizziness, mouth instability and sweating. Dysphoria, delirium, bad dreams, hallucinations, itching, urticaria, urinary retention, myoclonic movements, seizures, and respiratory depression are more rare side effects.
The adjuvant drugs that can be used in every step of the step treatment are corticosteroids, anticonvulsants, antidepressants, neuroleptics, local anesthetics, antihistamines and psychostimulants.
In many centers, there are more invasive procedures as the fourth step in cases where these three-step treatment is not sufficient. Parenteral opioids are a method which can be used particularly in the treatment of acute severe exacerbation pain. Epidural and intrathecal opioids can be used in the treatment of cancer pain with very different pumps and ports. Patients to be placed in these devices must be carefully selected and the use of the pump or port should be very well taught. Life expectancy plays a role in the selection of such devices. In particular, the use of lower cost port or catheter systems is recommended for patients with short life expectancy.
Neurostatistics techniques are also frequently used in cancer patients. Peripheral and sympathetic neurolytic blocks may be preferred in place of pain. Splanchnic, celiac, superior hypogastric and impar ganglion blocks can be applied in cancer pain. Other than these, cordocentesis can be performed in unilateral pain in conjunction with surgery or percutaneous computerized tomography.