Adult Cancer Pain, Version 3.2019, NCCN Clinical Practice Guidelines in Oncology

In recent years, the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Adult Cancer Pain have undergone substantial revisions focusing on the appropriate and safe prescription of opioid analgesics, optimization of nonopioid analgesics and adjuvant medications, and integration of nonpharmacologic methods of cancer pain management. This selection highlights some of these changes, covering topics on management of adult cancer pain including pharmacologic interventions, nonpharmacologic interventions, and treatment of specific cancer pain syndromes. The complete version of the NCCN Guidelines for Adult Cancer Pain addresses additional aspects of this topic, including pathophysiologic classification of cancer pain syndromes, comprehensive pain assessment, management of pain crisis, ongoing care for cancer pain, pain in cancer survivors, and specialty consultations.

Prevalence of Neuropathic Pain in Cancer Patients: Pooled Estimates From a Systematic Review of Published Literature and Results From a Survey Conducted in 50 Italian Palliative Care Centers

CONTEXT

Because of the increasing body of literature on neuropathic cancer pain (NCP), an accurate estimate of its prevalence requires recurring updates.

OBJECTIVES

To provide this estimate using information from a systematic review and a survey.

METHODS

Using MEDLINE, Embase, and a previous review, we searched for studies published up to 2014 reporting data on NCP prevalence in adult cancer populations. Pooled prevalence rates from observational prospective studies were computed. The association between NCP prevalence and possible predictors was investigated for oncology and palliative settings. Prevalence rates were extracted from a questionnaire answered by 137 physicians working in 50 Italian centers of palliative care. Estimates from studies conducted in palliative settings and from the experts were analyzed separately and eventually pooled with an informative Bayesian random-effect model.

RESULTS

Twenty-nine observational studies were identified. The overall pooled prevalence was 31.2%, with high heterogeneity; similar figures were observed when oncology and palliative settings were individually considered. A slightly higher prevalence of NCP was detected for hospice/inpatients as compared to outpatients, in both settings. The mean NCP prevalence reported by the survey experts was 44.2%; the pooled Bayesian estimate for the palliative setting corresponded to 43.0% (95% CI: 40.0-46.0). The subgroup with the lowest heterogeneity and where the literature and experts' estimates were closest is hospice/inpatients, with a pooled Bayesian prevalence rate of 34.9% (95% CI: 29.9-41.0).

CONCLUSION

The systematic review and the survey suggest that more than one in three patients with cancer pain also experiences NCP.

Non-pharmacological treatment for neuropathic pain in children with cancer

Neuropathic pain (NP) associated with childhood cancer is currently a difficult problem to control. It is treated with drugs that not only fail to provide the expected improvements, but which also have side effects. Therefore, the main aim of this pilot study is to assess whether non-pharmacological treatments, Graded Motor Imagery (GMI) and Neural Mobilization (NM), have a positive effect on this pain, thus improving the associated comorbid factors and, consequently, the quality of life of the children. In an n = 6, the results after 4 weeks of treatment show a 10-point improvement in the pain threshold and a 3.1-point improvement in the perception of pain.

Flupirtine enhances the anti-hyperalgesic effects of morphine in a rat model of prostate bone metastasis

OBJECTIVE

Current treatments for cancer pain are often inadequate, particularly when metastasis to bone is involved. The addition to the treatment regimen of another drug that has a complementary analgesic effect may increase the overall analgesia without the necessity to increase doses, thus avoiding dose-related side effects. This project investigated the synergistic effect of the addition of the potassium channel (KCNQ2-3) modulator flupirtine to morphine treatment in a rat model of prostate cancer-induced bone pain.

DESIGN

Syngeneic prostate cancer cells were injected into the right tibia of male Wistar rats under anesthesia. This led to expanding tumor within the bone in 2 weeks, together with the concurrent development of hyperalgesia to noxious heat. Paw withdrawal thresholds from noxious heat were measured before and after the maximum non-sedating doses of morphine and flupirtine given alone and in combinations. Dose-response curves for morphine (0.13-5.0 mg/kg ip) and flupirtine (1.25-10.0 mg/kg ip) given alone and in fixed-dose combinations were plotted and subjected to an isobolographic analysis.

RESULTS

Both morphine (ED₅₀ = 0.74 mg/kg) and flupirtine (ED₅₀ = 3.32 mg/kg) caused dose-related anti-hyperalgesia at doses that did not cause sedation. Isobolographic analysis revealed that there was a synergistic interaction between flupirtine and morphine. Addition of flupirtine to morphine treatment improved morphine anti-hyperalgesia, and resulted in the reversal of cancer-induced heat hyperalgesia.

CONCLUSIONS

These results suggest that flupirtine in combination with morphine may be useful clinically to provide better analgesia at lower morphine doses in the management of pain caused by tumors growing in bone.

Overview of supportive care in patients receiving chemotherapy: antiemetics, pain management, anemia, and neutropenia

With advancements in the field of oncology, more and more people are living with cancer. The prevalence of invasive cancer in the United States is estimated to be almost 12 million. The treatment of cancer as well as the malignancy itself can cause an immense number of side effects and other complications. This article explores the fundamentals of supportive care in patients receiving chemotherapy and radiation treatment including prevention of nausea and vomiting, pain management, treatment of anemia and neutropenia. Proper supportive care can help improve clinical outcomes, reduce medical costs, and help patients with cancer live longer, happier, and healthier lives. For these reasons, it is important for pharmacists to possess a solid understanding of how to prevent and treat the adverse effects of chemotherapy and radiation treatment.

Prevalence, etiology, and management of neuropathic pain in an Indian cancer hospital

Neuropathic pain is still an under-diagnosed and undertreated problem in third world countries. This retrospective study was undertaken to detect the prevalence, etiology and treatment profile of neuropathic pain in cancer. During January-December 2007, 716 new cancer pain patients were examined in Tata Memorial Hospital Pain Clinic. A total of 180 patients with a mean age of 47.14 yrs were found to have neuropathic pain characteristics on the basis of clinical impression, site of pain and the underlying cause i.e. due to tumor itself or cancer therapy. Head and neck cancer (32.2%) was found to be the most common cause of neuropathic pain, followed by breast (20.6%), thoracic (14.4%), genitourinary or gynecology (10.0% each), GI (9.4%), and medical oncology (2.8%). About 56% patients were post surgery, 44.4% post chemotherapy and 51.1% patients were post radiotherapy. The most common site of pain was thoracic (36.7%) due to primary or secondary metastatic disease. Pricking type of pain was the most characteristic feature (47.8%) followed by shooting pain (38.3%). The mean pain score was 5.96 +/- 1.5 (SD) and mean duration (months) of pain was 2.8 +/- 2.5. Neuropathic pain was found commonly associated with somatic pain (59.4%). The most common pharmacological agents prescribed were: tricyclic antidepressants (93.9%), anticonvulsants (66%), Opioids (85%), and nonsteroidal anti-inflammatory drugs (NSAIDs) (97.2%). Only 35% patients followed up more than once at the pain clinic. The most common and challenging patients were of orofacial pain. Nerve blocks techniques have a limited role in neuropathic pain.

Classification of pain in cancer patients--a systematic literature review

One of the aims of the European Palliative Care Research Collaborative (EPCRC) is to achieve consensus on a classification system for cancer pain. We performed a systematic literature review to identify existing classification systems and domains/items used to classify cancer patients with pain. In a systematic search in the databases Medline and Embase, covering 1986-2006, 692 hits were obtained. 92 papers were evaluated to address pain classification. Six standardised classification systems were identified; three of them systematically developed and partially validated. Both pain characteristics and patient characteristics relevant for cancer pain classification were included in the classification systems. All but one of the standardised systems aim at predicting treatment response or adequacy of treatment. Several domains and items used to describe cancer pain but not formally described as part of a classification system were also identified and systematized. The existing approaches to pain classification in cancer patients are different, mostly not thoroughly validated, and none is widely applied. An internationally accepted classification system for cancer pain could improve research and cancer pain management. This systematic review suggests a need for developing an international consensus on how to classify pain in cancer patients.

Word Choices of Advanced Cancer Patients: Frequency of Nociceptive and Neuropathic Pain

The purpose of this study was to determine if nociceptive and/or neuropathic pain in advanced cancer patients could be identified by word selections made on the McGill Melzack Pain Questionnaire. Theoretical definitions for nociceptive and neuropathic pain provided a framework for categorizing the word descriptors in the McGill Melzack Pain Questionnaire's sensory and miscellaneous dimensions. A description study design was used to group word frequencies by primary site and pain type. The participants were 76 advanced cancer patients who received home-based hospice services. A wide range of word choices for lung cancer patients supported both nociceptive and neuropathic pain. Individuals with colon and liver cancer selected words that described 2 types of nociceptive (visceral, somatic) pain, while those with prostate cancer noted somatic pain. A set frequency was not reached by individuals with breast, pancreatic, gastric, and other advanced cancers. This study provided evidence that advanced cancer patients select words that describe nociceptive and neuropathic pain types.

Sensory neuron targeting by self-complementary AAV8 via lumbar puncture for chronic pain

Lumbar puncture (LP) is an attractive route to deliver drugs to the nervous system because it is a safe bedside procedure. Its use for gene therapy has been complicated by poor vector performance and failure to target neurons. Here we report highly effective gene transfer to the primary sensory neurons of the dorsal root ganglia (DRGs) with self-complementary recombinant adeno-associated virus serotype 8 (sc-rAAV8) modeling an LP. Transgene expression was selective for these neurons outlining their cell bodies in the DRGs and their axons projecting into the spinal cord. Immunohistochemical studies demonstrated transduction of cells positive for the nociceptive neuron marker vanilloid receptor subtype 1, the small peptidergic neuron markers substance P and calcitonin gene-related peptide, and the nonpeptidergic neuron marker griffonia simplicifolia isolectin B4. We tested the efficacy of the approach in a rat model of chronic neuropathic pain. A single administration of sc-rAAV8 expressing the analgesic gene prepro-beta-endorphin (ppbetaEP) led to significant (P < 0.0001) reversal of mechanical allodynia for >/=3 months. The antiallodynic effect could be reversed by the mu-opioid antagonist naloxone 4 months after gene transfer (P < 0.001). Testing of an alternative nonopioid analgesic gene, IL-10, alone or in combination with ppbetaEP was equally effective (P < 0.0001). All aspects of the procedure, such as the use of an atraumatic injection technique, isotonic diluent, a low-infusion pressure, and a small injection volume, are consistent with clinical practice of intrathecal drug use. Therefore, gene transfer by LP may be suitable for developing gene therapy-based treatments for chronic pain.

Orofacial pain and neurosensory disorders and dysfunction in cancer patients

Orofacial pain and altered nerve sensation may be the initial sign of oropharyngeal or nasopharyngeal cancer. This article focuses on the most common orofacial pain conditions and neurosensory alterations that affect cancer patients, such as neuropathic pain, muscle spasm or contractures, mucositis, and increased or decreased sensory discrimination in the affected area. The various pharmacotherapeutic modalities for cancer pain management ranging from non steroidal anti-inflammatory drugs (NSAIDs) for mild pain to opioids for severe pain are discussed in detail.

Experience with gabapentin for neuropathic pain in adolescents: report of five cases

Summary Gabapentin is an antiepileptic drug indicated for the treatment of partial seizures in children. Many studies have proved its analgesic action in the treatment of neuropathic pain in adults and we have noticed an analgesic action of gabapentin in neuropathic pain in children. Five patients treated in the Children's Hospital Pain Control Service for intractable neuropathic pain were included in gabapentin treatment. Four were cancer patients and one suffered from neuropathic pain in the neck (C3). The visual analog scale (VAS) scores of pain were compared before and during treatment with gabapentin. We noticed a rapid improvement, in 1 week, of our patients' VAS scores (from 9 or 10 to 4 or 3) with minimal adverse effects. In the follow-up period of 6 months we gradually reduced the dose of gabapentin. Our findings are that gabapentin should be included earlier in the treatment of neuropathic pain in adolescents, because it rapidly improves analgesia and has minimal side effects.

Neuropathic pain in children with cancer

Different mechanisms of cancer pain may involve somatic, visceral, and neural tissues. Pain that involves the neural tissues is classified as neuropathic pain and is less responsive to analgesics than pain that involves somatic and visceral tissues. Because young children are unable to describe the quality of pain, presence of neuropathic pain with cancer may be unrecognized and undetected. The purpose of this article is to explain the nature of neuropathic pain, to review the literature related to children with cancer that suggests the presence of neuropathic pain, to outline assessment strategies that may lead to appropriate detection of neuropathic pain in children, and to discuss challenges in the management of neuropathic pain. Future research is needed to characterize the intensity, location, quality, and duration of neuropathic pain in children. In addition, research that would determine the efficacy of opioids, nonsteroidal anti-inflammatory drugs, and adjuvant analgesics (antidepressants, anticonvulsants) is needed to increase the nurses' ability to assess and manage neuropathic pain in children with cancer.

Adjuvant Analgesics in Cancer Pain Management

Adjuvant analgesics are defined as drugs with a primary indication other than pain that have analgesic properties in some painful conditions. The group includes numerous drugs in diverse classes. Although the widespread use of these drugs as first-line agents in chronic nonmalignant pain syndromes suggests that the term "adjuvant" is a misnomer, they usually are combined with a less-than-satisfactory opioid regimen when administered for cancer pain. Some adjuvant analgesics are useful in several painful conditions and are described as multipurpose adjuvant analgesics (antidepressants, corticosteroids, alpha(2)-adrenergic agonists, neuroleptics), whereas others are specific for neuropathic pain (anticonvulsants, local anesthetics, N-methyl-D-aspartate receptor antagonists), bone pain (calcitonin, bisphosphonates, radiopharmaceuticals), musculoskeletal pain (muscle relaxants), or pain from bowel obstruction (octreotide, anticholinergics). This article reviews the evidence supporting the use of each class of adjuvant analgesic for the treatment of pain in cancer patients and provides a comprehensive outline of dosing recommendations, side effects, and drug interactions.