Bicentre, randomized, parallel-arm, sham-controlled trial of transcranial direct-current stimulation (tDCS) in the treatment of palliative care patients with refractory cancer pain

BACKGROUND

Pain is a common symptom in palliative care cancer patients and is often insufficiently relieved. In recent years, transcranial direct-current stimulation (tDCS) of the motor cortex has been shown to be effective to treat chronic pain, essentially neuropathic pain. We propose to test the efficacy of tDCS in patients experiencing cancer pain in the palliative care setting.

METHOD/DESIGN

This article describes the protocol of a bicentre, randomized, parallel-arm, sham-controlled clinical trial evaluating tDCS in the treatment of palliative care patients with refractory cancer pain. Seventy patients between the ages of 18 and 80 years experiencing refractory pain with a pain score of 4/10 on a numerical rating scale (NRS) ranging from 0 to 10 will be enrolled in this trial. The main exclusion criteria are patients unable to fill in the various rating scales and life expectancy less than 3 weeks. Treatment consists of 5 consecutive tDCS sessions targeting the motor cortex (one daily session for 5 days) on the contralateral side to the pain. After randomization (1:1 ratio), 35 patients will receive active stimulation and 35 patients will receive sham stimulation. The primary endpoint is the NRS score and the primary objective is a significant improvement of this score between the baseline score recorded between D-3 and D-1 and the score recorded 4 days after stopping treatment (D8). The secondary objectives are to evaluate whether this improvement is maintained 16 days after stopping treatment (D21) and whether the following scores are improved on D14 and D21: Brief Pain Inventory, Edmonton Symptom Assessment System, Hospital Anxiety and Depression scale, State-Trait Anxiety Inventory and Medication Quantification Scale.

DISCUSSION

Positive results of this trial would indicate that tDCS can improve pain and quality of life of cancer patients in the palliative care setting. Reduction of analgesic consumption and improvement of activities of daily living should allow many patients to return home with a decreased workload for caregivers.

Effectiveness of Adjunctive Analgesics in Head and Neck Cancer Patients Receiving Curative (Chemo-) Radiotherapy: A Systematic Review

OBJECTIVE

Our aim was to give an overview of the effectiveness of adjunctive analgesics in head and neck cancer (HNC) patients receiving (chemo-) radiotherapy.

DESIGN

Systematic review.

INTERVENTIONS

This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Embase, Web of Science, the Cochrane Library, and ClinicalTrials.gov were searched for studies concerning "head neck cancer," "adjunctive analgesics," "pain," and "radiotherapy."

OUTCOME MEASURES

Pain outcome, adverse events, and toxicity and other reported outcomes, for example, mucositis, quality of life, depression, etc.

RESULTS

Nine studies were included in our synthesis. Most studies were of low quality and had a high risk of bias on several domains of the Cochrane Collaboration tool. Only two studies comprised high-quality randomized controlled trials in which pregabalin and a doxepin rinse showed their effectiveness for the treatment of neuropathic pain and pain from oral mucositis, respectively, in HNC patients receiving (chemo-) radiotherapy.

CONCLUSIONS

More high-quality trials are necessary to provide clear evidence on the effectiveness of adjunctive analgesics in the treatment of HNC (chemo-) radiation-induced pain.

[Drug management of cancer-related peripheral neuropathic pain: A systematic review of the literature]

The objective of the present systematic literature review was to provide an update on medical treatment of neuropathic pain in cancer patients. The number of cancer patients is steadily increasing. Pain is frequent in cancer patients. Few studies have focused on medical treatment of pain, and especially of neuropathic pain, in current or former cancer patients. The present systematic review of all studies published between December 2012 and August 2018 was intended to estimate the scale of this lack. In all, 27 articles were identified on a systematic PubMed search and from the authors' personal knowledge, confirming that scant data have been published. The heterogeneity of cancer patients, of cancer, and of pain go some way toward explaining this scarcity. Guidelines, founded mainly on results from non-cancer patients, recommend tricyclic antidepressants and antiepileptic drugs; local treatments have the advantage of good systemic tolerance. Larger-scale studies taking account of the etiology of neuropathic pain, its characteristics (strictly neuropathic or mixed) and patient characteristics (awaiting treatment, under treatment, recent or non-recent survivor, or in terminal phase) along the care pathway are needed to improve knowledge. The results of the present literature analysis can help future research.

Intractable Central Pain in a Patient With Diffuse Glioma

Central neuropathic pain can be difficult to treat and, subsequently, cause a great amount of disability and distress to patients, which limits quality of life. Common etiologies include the following: stroke, spinal cord injury, multiple sclerosis, infection, vasculitis, and malignancy. This case is a description of an 18-yr-old male patient diagnosed with a grade IV diffuse glioma who experienced severe neuropathic pain refractory to first-line treatment options including the following: gabapentinoids, tricyclic antidepressants, and selective serotonin and norepinephrine reuptake inhibitors. The patient remained on high-dose oral gabapentin as well as methadone and high-dose oxycodone for pain control at the time of submission. The aims of this case report were to review the nociceptive pathways and to explore the role of opioids in central neuropathic pain secondary to neoplasm because a better understanding of these topics can aid physiatrists in better taking care of these patients and improving function and quality of life.

Cancer and orofacial pain

BACKGROUND

Cancer pain is a devastating condition. Pain in the orofacial region, may be present as the single symptom of cancer or as a symptom of cancer in its later stages. This manuscript revises in a comprehensive manner the content of the conference entitled "Orofacial Pain and Cancer" (Dolor Orofacial y Cancer) given at the VI Simposio International "Advances in Oral Cancer" on the 22 July, 2016 in San Sebastioan-Donostia, Spain.

MATERIAL AND METHODS

We have reviewed (pubmed-medline) from the most relevant literature including reviews, systematic reviews and clinical cases, the significant and evidence-based mechanisms and mediators of cancer-associated facial pain, the diverse types of cancers that can be present in the craniofacial region locally or from distant sites that can refer to the orofacial region, cancer therapy that may induce pain in the orofacial region as well as discussed some of the new advancements in cancer pain therapy.

RESULTS

There is still a lack of understanding of cancer pain pathophysiology since depends of the intrinsic heterogeneity, type and anatomic location that the cancer may present, making more challenging the creation of better therapeutic options. Orofacial pain can arise from regional or distant tumor effects or as a consequence of cancer therapy.

CONCLUSIONS

The clinician needs to be aware that the pain may present the characteristics of any other orofacial pain disorder so a careful differential diagnosis needs to be given. Cancer pain diagnosis is made by exclusion and only can be reached after a thorough medical history, and all the common etiologies have been carefully investigated and ruled out. The current management tools are not optimal but there is hope for new, safer and effective therapies coming in the next years.

Methadone as first-line opioid treatment for cancer pain in a developing country palliative care unit

PURPOSE

The use of methadone for cancer pain is limited by the need of expertise and close titration due to variable half-life. Yet, it is a helpful palliative strategy in low-resources countries given its long-acting effect at low cost and worth additional study. Our aim was to describe the prescription and outcomes of methadone as a first-line treatment for cancer pain in a tertiary palliative care unit (PCU) in Argentina.

METHODS

Retrospective review of medical records of patients with moderate to severe cancer pain seen at the PCU in 1-year period, who initiated strong opioids at the first consultation. Data collected during the first month of treatment included disease and pain characteristics, initial and final opioid type and dose and need for opioid rotation.

RESULTS

Methadone was the most frequent opioid both at the initial and last assessment (71 and 66 % of the prescriptions). In all, treatment with strong opioids provided considerable decrease in pain intensity (p < 0.001) with low and stable opioid dose. Median and interquartile range (IR) of oral morphine equivalent daily dose (OMEDD) was 26 (16-32) and 39 (32-55) mg for initial and final assessments, respectively (p = 0.3). In patients initiated with methadone, the median (IR) daily methadone dose was 5 (4-6) mg at first and 7.5 (6-10) mg at final assessment, and the median (IR) index of opioid escalation was 0 (0-4) mg; (p < 0.05). Patients on methadone underwent less percentage of opioid rotation (15 versus 50 %; p < 0.001) and longer time to rotation (20.6 ± 4.4 versus 9.0 ± 2.7 days; p < 0.001) than patients on other opioids.

CONCLUSIONS

Results indicate the preference of methadone as first-line strong opioid treatment in a PCU, providing good pain relief at low doses with low need for rotation. Several considerations about the costs of strong opioids in the region are given.

Cancer and Referred Facial Pain

Orofacial pain may be a symptom of diverse types of cancers as a result of local or distant tumor effects. The pain can be presented with the same characteristics as any other orofacial pain disorder, and this should be recognized by the clinician. Orofacial pain also can arise as a consequence of cancer therapy. In the present article, we review the mechanisms of cancer-associated facial pain, its clinical presentation, and cancer therapy associated with orofacial pain.

Efficacy and safety of pregabalin in patients with neuropathic cancer pain undergoing morphine therapy

AIM

To evaluate the efficacy and the safety of pregabalin (PGB)-morphine combination for the treatment of neuropathic cancer pain (NCP).

METHODS

In this double-blind, randomized, placebo (PL)-controlled crossover study, 40 cancer patients with severe NCP were randomized into two groups (20 per group): PGB-PL and PL-PGB. Patients in the PGB-PL group received PGB plus oral morphine in phase I, and PL plus oral morphine in phase II. The treatment sequence for the PL-PGB group was PL plus oral morphine in phase I, and PGB plus oral morphine in phase II. These 2-week treatment periods were separated by a 1-week washout period. The primary outcome measure was the decrements in morphine dose; secondary outcomes included quantitative assessments of sleep (rated according to the Medical Outcomes Study Sleep Scale), the Constipation Assessment Scale and adverse effects.

RESULTS

The mean minimal effective dose of morphine was 184.4 ± 69.9 mg/day in the period of PGB treatments, which was significantly lower than that of PL-controls (228.7 ± 66.9 mg/day; P < 0.001) and baseline (247.5 ± 80.0 mg/day; P < 0.001). Compared with PL, PGB resulted in a significant sleep improvement as measured by sleep disturbance, sleep quantity, and sleep problems index (P < 0.001), as well as a Constipation Assessment Scale reduction (P < 0.001). PGB resulted in a higher frequency of dry mouth and somnolence than PL (P < 0.05).

CONCLUSION

PGB enhances the efficacy of oral morphine and reduces dose-related adverse reactions. The PGB-morphine combination is an effective approach to controlling NCP.

Neuropathic cancer pain: What we are dealing with? How to manage it?

Cancer pain is a serious health problem, and imposes a great burden on the lives of patients and their families. Pain can be associated with delay in treatment, denial of treatment, or failure of treatment. If the pain is not treated properly it may impair the quality of life. Neuropathic cancer pain (NCP) is one of the most complex phenomena among cancer pain syndromes. NCP may result from direct damage to nerves due to acute diagnostic/therapeutic interventions. Chronic NCP is the result of treatment complications or malignancy itself. Although the reason for pain is different in NCP and noncancer neuropathic pain, the pathophysiologic mechanisms are similar. Data regarding neuropathic pain are primarily obtained from neuropathic pain studies. Evidence pertaining to NCP is limited. NCP due to chemotherapeutic toxicity is a major problem for physicians. In the past two decades, there have been efforts to standardize NCP treatment in order to provide better medical service. Opioids are the mainstay of cancer pain treatment; however, a new group of therapeutics called coanalgesic drugs has been introduced to pain treatment. These coanalgesics include gabapentinoids (gabapentin, pregabalin), antidepressants (tricyclic antidepressants, duloxetine, and venlafaxine), corticosteroids, bisphosphonates, N-methyl-D-aspartate antagonists, and cannabinoids. Pain can be encountered throughout every step of cancer treatment, and thus all practicing oncologists must be capable of assessing pain, know the possible underlying pathophysiology, and manage it appropriately. The purpose of this review is to discuss neuropathic pain and NCP in detail, the relevance of this topic, clinical features, possible pathology, and treatments of NCP.

Sciatic nerve transection modulates oxidative parameters in spinal and supraspinal regions

Neuropathic pain is a very common dysfunction caused by several types of nerve injury. This condition leads to a variety of pathological changes in central nervous system regions related to pain transmission. It has been demonstrated that nociception is modulated by reactive oxidative species and treatments with antioxidant compounds produce antinociceptive effects. Thus, the aim of the present study was to investigate oxidative parameters in spinal and supraspinal regions following sciatic nerve transection (SNT). In behavioral assessments, animals showed mechanical allodynia and a significant functional impairment following SNT, measured by von Frey hairs test and sciatic functional index, respectively. Superoxide dismutase activity was increased 3 and 7 days following SNT in cerebral cortex and brainstem. Catalase activity was also increased in cerebral cortex 3 days after SNT. Ascorbic acid levels were decreased 7 days in the spinal cord only in SNT group. We also showed an increase in lipid peroxidation in cerebral cortex and brainstem 3 days after surgery in SNT and sham groups. These results showed that supraspinal regions also exhibit changes in antioxidant activity after SNT and demonstrate an intricate relationship among antioxidant defenses in different regions of the neuro axis related to pain transmission.