Cancer pain for the 21st century: stepping off the ladder, stepping up to new challenges

Non-opioid Analgesics and Emerging Therapies

Pain is a common and debilitating symptom of cancer. Cancer-related pain can occur at any point along the continuum from diagnosis to treatment to survivorship¹. A systematic review published in 2016 estimated the prevalence of cancer pain to be 55% in those undergoing antineoplastic treatment, 66.4% in advanced cancer, and 39.3% in the post-treatment population. Thirty-eight percent of cancer patients in this pooled analysis experienced moderate to severe pain².

Optimizing cancer pain management in resource-limited settings

Purpose

Adequate cancer pain management (CPM) is challenging in resource-limited settings, where current international guideline recommendations are difficult to implement owing to constraints such as inadequate availability and accessibility of opioids, limited awareness of appropriate opioid use among patients and clinicians, and lack of guidance on how to translate the best evidence into clinical practice. The multinational and multidisciplinary CAncer Pain managEment in Resource-limited settings (CAPER) Working Group proposes a two-step initiative to bridge clinical practice gaps in CPM in resource-limited settings.

Methods

A thorough review of the literature, a steering committee meeting in February 2017, and post-meeting teleconference discussions contributed to the development of this initiative. As a first step, we developed practical evidence-based CPM algorithms to support healthcare providers (HCPs) in tailoring treatment according to availability of and access to resources. The second part of the initiative proposes a framework to support an effective implementation of the CPM algorithms that includes an educational program, a pilot implementation, and an advocacy plan.

Results

We developed CPM algorithms for first-line use, breakthrough cancer pain, opioid rotation, and refractory cancer pain based on the National Comprehensive Cancer Network guidelines and expert consensus. Our proposed educational program emphasizes the practical elements and illustrates how HCPs can provide optimal CPM according to evidence-based guidelines despite varied resource limitations. Pilot studies are proposed to demonstrate the effectiveness of the algorithms and the educational program, as well as for providing evidence to support a draft advocacy document, to lobby policymakers to improve availability and accessibility of analgesics in resource-limited settings.

Conclusions

These practical evidence-informed algorithms and the implementation framework represent the first multinational step towards achieving optimal CPM in resource-limited settings.

Electronic supplementary material

The online version of this article (10.1007/s00520-018-4471-z) contains supplementary material, which is available to authorized users.

Tetrodotoxin for Moderate to Severe Cancer-Related Pain: A Multicentre, Randomized, Double-Blind, Placebo-Controlled, Parallel-Design Trial

Objective

This study evaluated subcutaneous injections of tetrodotoxin (TTX) for the treatment of moderate to severe, inadequately controlled cancer-related pain.

Methods

Eligible patients were randomized to receive TTX (30 μg) or placebo subcutaneously twice daily for four consecutive days. Efficacy was assessed using pain and composite endpoints (including pain and quality of life measures), and safety was evaluated using standard measures.

Results

165 patients were enrolled at 19 sites in Canada, Australia, and New Zealand, with 149 patients in the primary analysis “intent-to-treat” population. The primary analysis supports a clinical benefit of TTX over placebo based on the pain endpoint alone with a clinically significant estimated effect size of 16.2% (p = 0.0460). The p value was nominally statistically significant after prespecified (Bonferroni Holm) adjustment for the two primary endpoints but not at the prespecified two-sided 5% level. The mean duration of analgesic response was 56.7 days (TTX) and 9.9 days (placebo). Most common adverse events were nausea, dizziness, and oral numbness or tingling and were generally mild to moderate and transient.

Conclusions

Although underpowered, this study demonstrates a clinically important analgesic signal. TTX may provide clinically meaningful analgesia for patients who have persistent moderate to severe cancer pain despite best analgesic care. This clinical study is registered with ClinicalTrials.gov (NCT00725114).