Interventional options for the management of refractory cancer pain--what is the evidence?

Our plain-English summary of Interventional options for the management of refractory cancer pain--what is the evidence?, by P. Vayne-Bossert, B. Afsharimani, P. Good, et al (Supportive Care in Cancer, 2016).

The study

• Authors: P. Vayne-Bossert, B. Afsharimani, P. Good, P. Gray, J. Hardy
• Journal: Supportive Care in Cancer
• Published: 2016;24(3):1429-38
• Type of article: Systematic review
• Cited by: 41 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Purpose: Pain is the most common symptom in cancer patients. Standard pain treatment according to the WHO three-step analgesic ladder provides effective pain management in approximately 70-90% of cancer patients. Refractory pain is defined as not responding to "standard" treatments. Interventional analgesic techniques can be used in an attempt to control refractory pain in patients in whom conventional analgesic strategies fail to provide effective pain relief or are intolerable due to severe adverse effects. This systematic review aims to provide the latest evidence on interventional refractory pain management in cancer patients.

Methods: Systematic literature search in Cochrane, EMBASE and PubMed including reviews and randomised controlled trials (RCTs) and non-randomised controlled trials in the absence of reviews.

Results: Neuraxial analgesia may play a role in refractory cancer pain management. Paravertebral blocks decrease the incidence of persistent post-surgical pain after breast cancer. Coeliac plexus blocks improve pain scores in refractory pancreatic cancer pain for up to 4 weeks after the intervention with fewer burdensome side effects as compared to opioids. Cordotomy has mainly been studied in mesothelioma, and the case series suggest possible benefit for pain at the expense of a relatively high risk of side effects.

Conclusions: Overall, very few RCTs have been conducted on interventional pain techniques. In reality, it is very difficult to undertake large controlled trials for a number of reasons. Therefore, today's best evidence for practice may be from large case series of comparable patients with careful response and toxicity evaluation and follow-up.

In plain English

This article was a review, not an original study. The authors searched Cochrane, EMBASE and PubMed mainly for reviews, and for controlled trials where none existed, on invasive treatments for cancer pain when standard treatment failed to relieve it or caused intolerable side effects. They concluded that drug delivery into the spine may play a role, and that coeliac plexus blocks improved pancreatic cancer pain for up to 4 weeks. Mesothelioma appeared under cordotomy, which creates a permanent lesion in a spinal cord pain pathway. A previous review they summarised found only nine case series on cordotomy for mesothelioma pain, with 160 patients in total. In six of those studies, which compared pain before and after, most patients reported improvement. Motor weakness was reported in 15 of 127 patients and respiratory failure in one. The authors saw possible benefit at the expense of a relatively high risk of side effects. Overall they found very few randomised trials. They concluded that the best current evidence may come from large, carefully followed case series. The article does not discuss asbestos exposure.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Review of the published literature (described by the authors as a systematic review), focused on existing reviews rather than new patient data
• Who was studied: Published reviews and controlled trials on cancer patients whose pain was not relieved by conventional treatment, or whose conventional treatment caused intolerable severe adverse effects. These were found in Cochrane, EMBASE and PubMed with no limit on publication date.
• Exposure: Not an asbestos exposure study. The 'exposures' were interventional pain treatments: cement fixation of spinal bones, neuraxial (spinal) drug delivery, nerve blocks, nerve-destroying procedures including cordotomy, coeliac plexus block and spinal cord stimulation
• Main results:
  • An earlier review summarised by the authors, on cordotomy for mesothelioma-related pain, included only 9 case series with 160 patients in total
  • In that cordotomy review, the six studies that compared pain scores before and after the procedure found that most patients reported positive pain outcomes
  • In the cordotomy review, motor weakness was reported in 15 of 127 patients (11.87%), mirror pain in 6 (two of whom still had pain at 28 days), and respiratory failure in one patient
  • The authors judged that the cordotomy case series suggest possible pain benefit at the cost of a relatively high risk of side effects
  • In a meta-analysis of seven randomised trials of coeliac plexus block for pancreatic cancer pain, pain outcomes were better at 4 weeks but not at 8 weeks after the procedure
  • The authors concluded that the evidence suggests neuraxial (epidural or intrathecal) analgesia may play a role in managing refractory cancer pain
  • In a Cochrane review summarised by the authors, paravertebral blocks given for breast cancer surgery reduced persistent pain 5 to 6 months later, reported as 'in 20% of the women'
  • For cement fixation of spinal bones (vertebroplasty and kyphoplasty) in cancer, reviews reported rates of complications and severe adverse events ranging from zero to 29%
  • For spinal cord stimulation in cancer patients, a Cochrane review found the evidence of benefit insufficient
• The authors' conclusion: The authors concluded that very few randomised trials exist for interventional pain techniques. They judged that the best current evidence for practice may come from large case series of comparable patients, with careful evaluation of response and side effects and careful follow-up.
• Limitations the authors state:
  • The quality of the included studies was not formally assessed or scored
  • Small uncontrolled trials and case series were not covered unless they were part of a review
  • Because the review was limited to reviews, many procedures used by specialists were not discussed

Topics

Medical terms in this study, explained in our Lexicon: Systematic Review, Mesothelioma.

Related studies

• Opioids in pain management of mesothelioma and lung cancer patients — E.K. Salminen, M. Silvoniemi, et al. (2013)
• Ultrasound guided continuous erector spinae plane block for pain management in pulmonary malignancy — T. Aydın, O. Balaban, et al. (2018)
• Clinical presentation of asbestosis with intractable pleural pain in the adult child of a taconite miner and radiographic demonstration of the probable pathology causing the pain — M.R. Harbut, C. Endress, et al. (2009)
• Unexpected complication of successful nerve block. Morphine induced respiratory depression precipitated by removal of severe pain — G.W. Hanks, R.G. Twycross, et al. (1981)
• A randomised study comparing the effectiveness of acupuncture or morphine versus the combination for the relief of dyspnoea in patients with advanced non-small cell lung cancer and mesothelioma — A. Minchom, R. Punwani, et al. (2016)
• Malignant mesothelioma: options for management — S. Singhal, L.R. Kaiser (2002)

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