Methadone and neuropathic cancer pain subcomponents: a prospective cohort pilot study

Cancer Pain Management: A Narrative Review of Current Concepts, Strategies, and Techniques

Pain is frequently reported during cancer disease, and it still remains poorly controlled in 40% of patients. Recent developments in oncology have helped to better control pain. Targeted treatments may cure cancer disease and significantly increase survival. Therefore, a novel population of patients (cancer survivors) has emerged, also enduring chronic pain (27.6% moderate to severe pain). The present review discusses the different options currently available to manage pain in (former) cancer patients in light of progress made in the last decade. Major progress in the field includes the recent development of a chronic cancer pain taxonomy now included in the International Classification of Diseases (ICD-11) and the update of the WHO analgesic ladder. Until recently, cancer pain management has mostly relied on pharmacotherapy, with opioids being considered as the mainstay. The opioids crisis has prompted the reassessment of opioids use in cancer patients and survivors. This review focuses on the current utilization of opioids, the neuropathic pain component often neglected, and the techniques and non-pharmacological strategies available which help to personalize patient treatment. Cancer pain management is now closer to the management of chronic non-cancer pain, i.e., "an integrative and supportive pain care" aiming to improve patient's quality of life.

Edmonton Classification System for Cancer Pain: Comparison of Pain Classification Features and Pain Intensity across Diverse Palliative Care Settings in Canada

Background: The goal of the Edmonton Classification System for Cancer Pain (ECS-CP) is to create an international classification system for cancer pain. Previous studies reinforce the need for standardized training to ensure consistency across assessors. There is no universally accepted classification for neuropathic pain. Objectives: Our primary objective was to describe the prevalence of ECS-CP features in a diverse sample of advanced cancer patients, using assessors with standardized training. The secondary objectives were to: (1) determine the prevalence of neuropathic pain using the Neuropathic Pain Special Interest Group (NeuPSIG) criteria and (2) examine the relationship between specific predictors: ECS-CP features, age, Palliative Performance Scale, Morphine Equivalent Daily Dose (MEDD), setting, and pain intensity; and neuropathic pain. Methods: A total of 1050 adult patients with advanced cancer were recruited from 11 Canadian sites. A clinician completed the ECS-CP and NeuPSIG criteria, and collected additional information including demographics and pain intensity (now). All assessors received standardized training. Results: Of 1050 evaluable patients, 910 (87%) had cancer pain: nociceptive (n = 626; 68.8%); neuropathic (n = 227; 24.9%); incident (n = 329; 36.2%); psychological distress (n = 209; 23%); addictive behavior (n = 51; 5.6%); and normal cognition (n = 639; 70.2%). The frequencies of ECS-CP features and pain intensity scores varied across sites and settings, with more acute settings having higher frequencies of complex pain features. The overall frequency of neuropathic pain was 24.9%, ranging from 11% (hospices) to 34.2% (palliative outpatient clinic) across settings. Multivariate logistic regression analysis revealed that age <60 years, MEDD ≥19 mg, pain intensity ≥7/10, and incident pain were significant independent predictors of neuropathic pain (p < 0.05). Conclusion: The ECS-CP was able to detect salient pain features across settings. Furthermore, the frequencies of neuropathic pain utilizing the NeuPSIG criteria fits within the lower-end of literature estimates (13%-40%). Further research is warranted to validate the NeuPSIG criteria in cancer pain.

The Use of Low-Dose Methadone as Add-On to Ongoing Opioid Treatment in Palliative Cancer Care—An Underrated Treatment?

The aim of this review is to summarize the current knowledge of low-dose methadone treatment in palliative cancer care. In Sweden, methadone is quite common in specialized palliative care, where almost a tenth of patients are prescribed this drug. Negative attitudes towards methadone do not seem to prevent it from being used for pain management, and by starting with low doses and then increasing slowly and gradually, methadone can apparently be introduced safely. It is still uncertain whether methadone has a better analgesic effect than other opioids. However, for pain relief in cancer patients with severe and complex cancer-related pain, NMDA receptor inhibition with methadone may, in selected cases, be an attractive alternative, especially in the form of low-dose supplements to other ongoing opioids. Due to long half-life and complex metabolism, the use of methadone requires an experienced physician and solid follow-up. Continuous administration of opioids, including low-dose methadone, has been proven effective and safe in reducing pain in dying patients without increasing the risk of confusion, regardless of age.

Treatment of Neuropathic Pain Directly Due to Cancer: An Update

Simple Summary

This review discusses treatment approaches for providing pain relief to oncological patients affected by pain caused by nerve damage due to the tumor, also known as neuropathic cancer pain. Although being encountered often and causing a relevant burden to these patients, neuropathic cancer pain remains still difficult to diagnose and treat. Strong evidence about the best drugs to be used remain limited, as do therapeutic choices.

Abstract

Neuropathic pain can be defined as pain related to abnormal somatosensory processing in either the peripheral or central nervous system. In this review article, with neuropathic cancer pain (NCP), we refer to pain due to nervous tissue lesions caused by the tumor or its metastases. Nervous tissue damage is the cause of cancer pain in approximately 40% of those experiencing cancer pain. Recognizing a neuropathic pathophysiology in these cases may be difficult and requires specific criteria that are not homogenously applied in clinical practice. The management of this type of pain can be challenging, requiring the use of specific non-opioid adjuvant drugs. The majority of the criteria for NCP diagnosis and management have been based mainly on results from the noncancer population, risking the failure of addressing the specific needs of this population of patients. In this review, we summarize current management options available for NCP and provide some insights on new promising treatments.