Review Question

What is the effectiveness of spinal cord stimulation (SCS) for cancer-related pain compared with standard care using conventional analgesic medication? The review also appraised risk and potential adverse effects associated with the use of SCS.

Type of Review

This is an updated Cochrane Review first published in The Cochrane Review in Issue 3, 2013. The search strategy was the same as that in the original review, a literature review using the following bibliographic databases: the Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and Chinese Biomedical Database in October 2014. In this update, it was again planned to include randomized controlled trials (RCTs), crossover trials, and potentially non-RCTs if no RCTs could be found.

Relevance for Nursing

Throughout the world, cancer-related pain has become a heavy burden on public health. It has been estimated that nearly 7 million people at any one time experience moderate to severe cancer-related pain, whether caused by the cancer itself or the treatment. Moderate to severe pain is often associated with an overall decrease in quality of life and can lead to depression, anxiety, and even suicide in extreme cases.1 Nurses need to be cognizant of all aspects of their patients' pain, its causes, and potential interventions. They need to follow evidence-based protocols to effectively manage their patients' pain.

Traditionally, standardized medication protocols have been used for improving cancer pain management. However, when this approach fails, then interventional pain management has been proposed as an adjunct therapy. Spinal cord stimulation has been studied and proven effective in the realm of treating chronic back pain and other nonmalignant types of pain. On the basis of that evidence, one of the more common nonmedication interventions sometimes used to modulate refractory pain in the patient with cancer is SCS.

Spinal cord stimulation involves placing electrodes on the spinal cord to control pain. These electrodes then deliver impulses that may reduce pain perception. The current techniques for SCS are minimally invasive and seem to have few adverse effects.

Therefore, nurses need to know and understand the evidence that exists regarding the process, risks, and benefits of SCS in caring for patients with cancer-related pain.

Characteristics of the Evidence

Because this was an update of a review first published in 2013, the search strategy for this update was the same as that for the original review. This review again researched the following bibliographic databases: the Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, and Chinese Biomedical Database in October 2014. Included in this updated search were again RCTs that compared SCS with other interventions, crossover trials that compared SCS with other interventions, and non-RCTs if no RCTs could be found. The literature search for this update found 121 potentially eligible articles. The initial search strategy found 430 articles, but by studying the titles and abstracts, the authors discarded 412 of those articles because of different scopes of diseases, different methods of interventions, or different aims other than pain management. Of the remaining articles, no RCTs were found, and multiple case reports and review articles were excluded. There were 4 before-and-after case series studies involving 92 participants with cancer included for descriptive analysis in the review. In conclusion, there were no new RCTs or studies identified to include in this updated review.

Summary of Key Evidence

Since the last version of this review, no new studies were found. In the 4 before-and-after case series studies included in this systematic review, clinical efficacy was reported as modest to excellent. More than 80% of participants reported at least a 50% reduction of pain intensity, with more than 50% of participants reporting decreased use of opioids. Major complications included infection at implantation sites, cerebrospinal fluid leakage, pain at electrode sites, dislodgement of electrodes, and system failure, although the incidence was very low. The follow-up period varied from 1 week to more than 1 year. All these studies were at a high risk of bias.1

Best Practice Recommendations

There were no new studies found since the original review. As a result, current evidence from small, low-quality studies is insufficient to establish the role of SCS in the treatment of refractory cancer-associated pain. Although the 4 before-and-after case series studies point to some benefit from SCS, those patients with refractory cancer pain should consult with experienced clinicians in pain management and palliative medicine. Those clinicians who choose to incorporate SCS into pain management regimens should base their decisions on their skill/expertise, the preference of their patients, and the availability of the best techniques in interventional pain management.

Research Recommendations

Studies that specifically focus on the early implementation of SCS in patients with cancer pain as compared with other treatment modalities (oral medications, opioids, intrathecal medication administration) are required. Future research should focus on RCTs with larger sample sizes that can quantify the benefits and risks of SCS, especially the effectiveness of pain management, quality of life improvement, and adverse effects.

Carolyn W. White, MSN, FNP-BC, GNP-BC, APRN, ACHPN

Carilion Clinic, Roanoke, Virginia

Reference