Recent advances in understanding and managing cancer pain

Targeting TRPV4 Channels for Cancer Pain Relief

Despite the unique and complex nature of cancer pain, the activation of different ion channels can be related to the initiation and maintenance of pain. The transient receptor potential vanilloid 4 (TRPV4) is a cation channel broadly expressed in sensory afferent neurons. This channel is activated by multiple stimuli to mediate pain perception associated with inflammatory and neuropathic pain. Here, we focused on summarizing the role of TRPV4 in cancer etiology and cancer-induced pain mechanisms. Many studies revealed that the administration of a TRPV4 antagonist and TRPV4 knockdown diminishes nociception in chemotherapy-induced peripheral neuropathy (CIPN). Although the evidence on TRPV4 channels' involvement in cancer pain is scarce, the expression of these receptors was reportedly enhanced in cancer-induced bone pain (CIBP), perineural, and orofacial cancer models following the inoculation of tumor cells to the bone marrow cavity, sciatic nerve, and tongue, respectively. Effective pain management is a continuous problem for patients diagnosed with cancer, and current guidelines fail to address a mechanism-based treatment. Therefore, examining new molecules with potential antinociceptive properties targeting TRPV4 modulation would be interesting. Identifying such agents could lead to the development of treatment strategies with improved pain-relieving effects and fewer adverse effects than the currently available analgesics.

The cytokines in tumor microenvironment: from cancer initiation-elongation-progression to metastatic outgrowth

It is a well-known fact that cancer can be augmented by infections and inflammation. In fact, chronic inflammation establishes a tumor-supporting-microenvironment (TME), which contributes to neoplastic progression. Presently, extensive research is going on to establish the interrelationship between infection, inflammation, immune response, and cancer. Cytokines are the most essential components in this linkage, which are secreted by immune cells and stromal cells of TME. Cytokines have potential involvement in tumor initiation, elongation, progression, metastatic outgrowth, angiogenesis, and development of therapeutic resistance. They are also linked with increased cancer symptoms along with reduced quality of life in advanced cancer patients. The cancer patients experience multiple symptoms including pain, asthenia, fatigue, anorexia, cachexia, and neurodegenerative disorders etc. Anti-cancer therapeutics can be developed by targeting cytokines along with TME to reduce the immunocompromised state and also modulate the TME. This review article depicts the composition and function of different inflammatory cells within the TME, more precisely the role of cytokines in cancer initiation, elongation, and progression as well as the clinical effects in advanced cancer patients. It also provides an overview of different natural compounds, nanoparticles, and chemotherapeutic agents that can target cytokines along with TME, which finally pave the way for cytokines-targeted anti-cancer therapeutics.

Targeting TRPV1 for Cancer Pain Relief: Can It Work?

Chronic intractable pain affects a large proportion of cancer patients, especially those with metastatic bone disease. Blocking sensory afferents for cancer pain relief represents an attractive alternative to opioids and other drugs acting in the CNS in that sensory nerve blockers are not addictive and do not affect the mental state of the patient. A distinct subpopulation of sensory afferents expresses the capsaicin receptor TRPV1. Intrathecal resiniferatoxin, an ultrapotent capsaicin analog, ablates TRPV1-expressing nerve endings exposed to the cerebrospinal fluid, resulting in permanent analgesia in women with cervical cancer metastasis to the pelvic bone. High-dose capsaicin patches are effective pain killers in patients with chemotherapy-induced peripheral neuropathic pain. However, large gaps remain in our knowledge since the mechanisms by which cancer activates TRPV1 are essentially unknown. Most important, it is not clear whether or not sensory denervation mediated by TRPV1 agonists affects cancer progression. In a murine model of breast cancer, capsaicin desensitization was reported to accelerate progression. By contrast, desensitization mediated by resiniferatoxin was found to block melanoma growth. These observations imply that TRPV1 blockade for pain relief may be indicated for some cancers and contraindicated for others. In this review, we explore the current state of this field and compare the analgesic potential of TRPV1 antagonism and sensory afferent desensitization in cancer patients.

Access to psychological treatment for chronic cancer-related pain in Sweden

OBJECTIVES

Cancer-related pain (CRP) is among the most frequent collateral effects of cancer, with chronic CRP, lasting at least 3 months, affecting >40% of cancer survivors. Evidence-based treatments, including pain-focused cognitive behavioral therapy (CBT), are available, but it appears that cancer patients/survivors are often poorly informed about CRP or the potential benefits of CBT for such pain. This study examined current experience of Swedish cancer patients/survivors in relation to CRP.

METHODS

Participants (N = 276; 83% female; mean age = 55.5 years, SD = 11.9) were recruited to an online survey via cancer websites in Sweden, and they provided information about their history of chronic CRP and whether they received information about or treatment for CRP from a healthcare professional.

RESULTS

Participants had a history of breast (36%), gynecological (12%), lung (10%), colon (8%), and other forms of cancer (36%). A majority (74%) reported a history of chronic CRP and being prescribed analgesic medications (70%). Less than half (47%) received information from their healthcare provider about the risk of CRP and only 13% with chronic CRP received psychological treatment, and of these, only 33% received CBT. Among those receiving psychological treatment for chronic CRP, satisfaction rates were moderate, reported as an average of 6 on a 0-10 scale (standard deviation 2.6).

CONCLUSIONS

Greater efforts are needed to raise awareness among cancer patients/survivors and healthcare providers about the risk of CRP and evidence-based interventions, including CBT, the first-line intervention for chronic pain. These efforts will need to be matched with increases in treatment capacity, particularly pain-focused CBT.

Exploring the Rules of Related Parameters in Transcutaneous Electrical Nerve Stimulation for Cancer Pain Based on Data Mining

INTRODUCTION

This study aims to investigate the regularity of related parameters in the treatment of cancer pain using transcutaneous electrical nerve stimulation (TENS).

METHODS

A comprehensive literature search was conducted in databases such as PubMed, Cochrane Library, Embase, Web of Science, OVID, CNKI, CBM, VIP, and WANNGFANG from inception up to December 2022. A database was established, and data mining techniques were applied to analyze the relevant TENS parameters.

RESULTS

A total of 27 articles were included, encompassing nine current frequencies, four retention times, four treatment frequencies, and two wave types. On the basis of the analysis of parameter association rules, the most closely related parameter combination for clinical TENS in the treatment of cancer pain was a current frequency of 2/100 Hz, a treatment frequency of once a day, a retention time of 30 min, and the dilatational wave. Moreover, the study involved 22 acupuncture points distributed along 13 meridians. According to the analysis of acupuncture point association rules, Hegu (LI04), Zusanli (ST36), and Sanyinjiao (SP06) were the most closely related acupuncture points and could be used in combination for clinical TENS in cancer pain treatment. Furthermore, cluster analysis was conducted on acupuncture points with a frequency ≥ 5, resulting in three categories: the first category included Sanyinjiao (SP06), Zusanli (ST36), Hegu (LI04), Jiaji point, and Neiguan (PC06); the second category included Ashi point; and the third category included Back shu point.

CONCLUSION

In the treatment of cancer pain using TENS, it is recommended to use a current frequency of 2/100 Hz, a treatment frequency of once a day, a retention time of 30 min, and the dilatational wave. The electrode positions were primarily selected from Ashi point, Back shu point, Sanyinjiao (SP06), Zusanli (ST36), Hegu (LI04), Jiaji point, and Neiguan (PC06) to achieve the best analgesic effect.

Cancer Pain and Non-Invasive Brain Stimulation-A Narrative Review

Background and Objectives: Pain is the most prevalent symptom in cancer patients. There is a paucity of data regarding non-invasive brain stimulation (NIBS) for the treatment of chronic pain in patients with cancer. The purpose of this article is to review the techniques of NIBS and present the published experiences of the oncological population. Materials and Methods: Databases including MEDLINE, Scopus, Web of Science, and the Cochrane Library were searched for articles on cancer patients with pain that was managed with non-invasive brain stimulation techniques. We included articles in English that were published from inception to January 2023. As studies were limited in number and had different designs and methodologies, a narrative review was considered as the best option to integrate data. Results: Four studies focusing on transcranial magnetic stimulation, six articles on transcranial direct current stimulation, and three articles regarding cranial electric stimulation were found and reviewed. Conclusions: Data are limited and not robust. Further studies in this field are required. Guidelines on NIBS for non-malignant chronic pain conditions provide good premises for cancer-related chronic pain.

Incorporation of Palliative Care in Gynecologic Oncology

PURPOSE OF REVIEW

This review serves to provide clarity on the nature, scope, and benefits of early palliative care integration into the management of patients with gynecologic malignancies.

RECENT FINDINGS

There is increased recognition that timely referral to palliative care improves quality of life for patients and their families by providing goal-concordant care that reduces physical and emotional suffering and limits futile and aggressive measures at the end of life. Palliative care services rendered throughout the continuum of illness ultimately increase engagement with hospice services and drive down health expenditures. Despite these myriad benefits, misconceptions remain, and barriers to and disparities in access to these services persist and warrant continued attention. Palliative care should be offered to all patients with advanced gynecologic cancers early in the course of their disease to maximize benefit to patients and their families.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Cancer aggravation due to persistent pain signals with the increased expression of pain-related mediators in sensory neurons of tumor-bearing mice

A growing body of evidence suggests that intractable pain reduces both the quality of life and survival in cancer patients. In the present study, we evaluated whether chronic pain stimuli could directly affect cancer pathology using tumor-bearing mice. For this purpose, we used two different models of chronic pain in mice, neuropathic pain and persistent postsurgical pain, with Lewis lung carcinoma (LLC) as tumor cells. We found that tumor growth was dramatically promoted in these pain models. As well as these pain models, tumor growth of LLC, severe osteosarcoma (AXT) and B16 melanoma cells was significantly promoted by concomitant activation of sensory neurons in AAV6-hM3Dq-injected mice treated with the designer drug clozapine-N-oxide (CNO). Significant increases in mRNA levels of vascular endothelial growth factor-A (Vegfa), tachykinin precursor 1 (Tac1) and calcitonin-related polypeptide alpha (Calca) in the ipsilateral side of dorsal root ganglion of AAV6-hM3Dq-injected mice were observed by concomitant activation of sensory neurons due to CNO administration. Moreover, in a model of bone cancer pain in which mice were implanted with AXT cells into the right femoral bone marrow cavity, the survival period was significantly prolonged by repeated inhibition of sensory neurons of AAV6-hM4Di-injected mice by CNO administration. These findings suggest that persistent pain signals may promote tumor growth by the increased expression of sensory-located peptides and growth factors, and controlling cancer pain may prolong cancer survival.

Efficacy of transcranial direct current stimulation (tDCS) on pain and shoulder range of motion in post-mastectomy pain syndrome patients: a randomized-control trial

Background

Post-mastectomy pain syndrome (PMPS) is a highly prevalent complication after surgical treatment for breast cancer, and it affects the patient’s quality of life in aspects of losing shoulder full range of motion, pain, and depression. Transcranial direct current stimulation (tDCS) is non-invasive brain stimulation technique that was used in numerous clinical applications and in pain reduction in cancer patients. However, the effectiveness of tDCS on PMPS has never been evaluated in an experimental study.

Aim

To investigate the effect of bilateral anodal tDCS of motor cortex (M1) on pain, depression, and shoulder range of motion (ROM) in post-mastectomy pain syndrome.

Study design

Randomized controlled trial.

Methods

A total of 30 female patients with post-mastectomy neuropathic pain were randomized into two groups; the intervention group which received bilateral tDCS on motor cortex (M1) and the control group that received sham bilateral tDCS on M1. As pain affects shoulder range of motion (ROM), shoulder ROM was measured by electronic goniometer pre- and post-tDCS application. In addition, the levels of pain and depression have been measured pre and post treatment. Pain has been measured with visual analogue scale (VAS) and depression with Beck-Depression-Inventory-BDI questionnaire (BDI).

Results

A significant difference was noted in group A regarding pain, depression and shoulder ROM (p= 0.001, p= 0.003, and p= 0.003, respectively). Between group comparison revealed a significant difference of VAS scores and shoulder flexion ROM between groups, the study group and the control group (p=0.041 and 0.048, respectively). Pain decreased by 32% and Shoulder flexion increased by 4.8% post-treatment while there were no significant difference in group B (p=0.567 and p=0.866, respectively).

Conclusions

The application of tDCS decreases the severity of pain and improves shoulder range of motion suffered by breast cancer patients after total mastectomy surgery.

Topical Traditional Chinese Medicines for Cancer Pain: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND AND OBJECTIVES

Safe and effective management of cancer-related pain is a worldwide challenge. In the search for treatment options, natural products used in Chinese herbal medicines (CHMs) have received attention in clinical studies for their effects on cancer-related pain. The objective of this systematic review is to evaluate the clinical evidence for topically applied CHMs as adjunctive treatments for cancer pain management.

METHODS

Nine biomedical databases and 4 clinical trial registries were searched for randomized-controlled trials (RCTs) that reported measures of pain and/or quality of life. Risk of bias was assessed using the Cochrane tool. Meta-analysis employed mean difference (MD) with 95% confidence intervals (random effects).

RESULTS

Twenty (20) RCTs (1636 participants) met the inclusion criteria. Meta-analyses were grouped based on the comparisons and outcome measures. For pain intensity, there was a greater reduction in the topical CHM group versus placebo (MD -0.72 [-1.04, -0.40]), no difference when compared to tramadol (MD -0.15 [-0.38, 0.08]), and a greater reduction when topical CHMs were combined with conventional analgesic medications (MD -0.67 [-0.93, -0.40]). Analgesic onset time was reduced in the CHM group compared to tramadol (MD -26.02 [-27.57, -24.47] minutes), and for CHMs combined with conventional medications (MD -19.17 [-21.83, -16.52] minutes). When CHMs were combined with analgesic medications, improvements were found for duration of analgesia (MD 1.65 [0.78, 2.51] hours), analgesic maintenance dose (MD -31.72 [-50.43, -13.01] milligrams/day), and quality of life.

CONCLUSION

Addition of topical CHMs to conventional analgesic medications was associated with improved outcomes for pain intensity, some other pain-related outcomes, and measures of quality of life. Limitations included methodological issues in some studies and considerable heterogeneity in some pooled results.

Spinal Cord Stimulation Meets Them All: An Effective Treatment for Different Pain Conditions. Our Experience and Literature Review

IntroductionSpinal Cord Stimulation (SCS) is an emerging minimally invasive technique which uses neuromodulation to manage different forms of intractable pain. SCS is a well-established option for the treatment of various pain conditions, and nowadays, indications are ever increasing.Materials and MethodsIn this study, we present our case series of 49 patients who underwent SCS at our Institution for the treatment of pain from different etiologies, and discuss our 10-year experience in SCS. For the purpose of this study, we also performed a systematic review of current indications and new perspectives in SCS.ResultsAmong our case series, patients were differentiated into two groups upon prior spinal surgery: patients who had undergone prior spinal surgery for back pain were defined as the "FBSS (failed back surgery syndrome) group," instead patient suffering from different types of pain but who had never undergone surgery were defined as the "naive group." As regards clinical response to SCS, 20 patients out of 36 (55.56%) were classified as responders in the FBSS group; in the "naïve" group, 10 patients out of 13 (76.92%) were classified as responders. Among the "not responders" group, several patients suffered from infections.Of the recent literature about SCS, 2124 records were screened and 37 studies were finally included in the qualitative synthesis for our systematic review.DiscussionIn case of FBSS, surgical revision is often associated with a high morbidity and corresponding low rates of success. Unfortunately, patients affected by chronic pain often become refractory to conservative treatments. Spinal Cord Stimulation (SCS) is nowadays considered as an effective therapy for several chronic and neuropathic pain conditions, such as failed back surgery syndrome. As regards the economic impact of SCS, implantation of an SCS system results in short-term costs increase, but the annual cumulative costs decrease during the following years after implantation, when compared to the costs of conventional management. Beyond the application for the treatment of FBSS, SCS has also been used for the treatment of other types of chronic non-oncological pain such as neuropathic pain and chronic back pain ineligible for surgical intervention. This evidence paved the way to establishing the potential role of SCS also for the treatment of oncological pain. However, the effectiveness and relative safety of SCS for cancer-related pain has not yet been adequately established.ConclusionsSpinal Cord Stimulation is a well-established treatment option in for FBSS. Beyond that, SCS has also been used for the treatment of "naive" patients, suffering from other types of chronic, both oncological and non-oncological, medical-refractory pain such as neuropathic pain and chronic back pain ineligible for surgical intervention.

2022 KLCA-NCC Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Scrambler Therapy Enhances Quality of Life in Cancer Patients in a Palliative Care Setting: A Randomised Controlled Trial

Objectives:

Given the known side effects of opioids and the negative impact of these side effects on quality of life (QOL), there is a need for therapies that can reduce opioid intake and improve QOL in patients suffering from cancer pain. Scrambler therapy (ST) is a neuromodulatory therapy that has been shown to reduce cancer pain, but its effect on QOL is not well understood. This study intended to evaluate the efficacy of ST for enhancing QOL in cancer patients through minimising pain and opioid intake.

Material and Methods:

This was a randomised controlled trial including 80 patients with head, neck and thoracic cancer. In both arms, patients were given pain management drugs following the WHO analgesic ladder for ten consecutive days. In the intervention arm each day ST was given. Pain, morphine intake, and QOL (WHOQOL-BREF) were assessed.

Results:

All domains of QOL improved significantly in the intervention arm in comparison to the control arm. In comparison to baseline, pain improved in both the intervention and the control arm on day 10 and at follow-up. However, QOL significantly improved in the intervention arm, while morphine intake decreased. In the control arm, QOL deteriorated, while morphine intake increased.

Conclusion:

ST significantly improved QOL. Since the increase in QOL took place along with a significantly lower morphine intake, the improvement in QOL may not only be explained by lower pain scores but, also, by a reduced intake of morphine, because the lower dosages of morphine will decrease the likelihood of side effects associated with the drug.

Non-pharmacological integrative therapies for chronic cancer pain

Objective

Chronic pain is one of the most detrimental symptoms exhibited by cancer patients, being an indication for opioid therapy in up to half of the patients’ receiving chemotherapy and in 90% of advanced cases. Various successful non-pharmacological integrative therapy options have been explored and implemented to improve the quality of life in these patients. This review aims to highlight the mechanisms implicated; assessment tools used for cancer pain and summarize current evidence on non-pharmacological approaches in the treatment of chronic cancer pain.

Data sources

A review of the literature was conducted using a combination of MeSH keywords including “Chronic cancer pain,” “Assessment,” “Non-pharmacological management,” and “Integrative therapy.”

Data summary

Data on the approach and assessment of chronic cancer pain as well as non-pharmacological integrative options have been displayed with the help of figures and tables. Of note, non-pharmacological integrative management was divided into three subcategories; physical therapy (involving exercise, acupuncture, massage, and transcutaneous electric nerve stimulation), psychosocial therapy (e.g. mindful practices, supportive therapy), and herbal supplementation.

Conclusions

The use of non-pharmacological integrative therapy in the management of chronic cancer pain has been grossly underestimated and must be considered before or as an adjuvant of other treatment regimens to ensure appropriate care.

Blocking Cancer-Nerve Crosstalk for Treatment of Metastatic Bone Cancer Pain

The tumor microenvironment is a complex milieu where neurons constitute an important non-neoplastic cell type. From "cancer neuroscience," the crosstalk between tumors and neurons favors the rapid growth of both, making the cancer-nerve interaction a reciprocally beneficial process. Thus, cancer-nerve crosstalk may provide new targets for therapeutic intervention against cancer and cancer-related symptoms. We proposed a nerve-cancer crosstalk blocking strategy for metastatic bone cancer pain treatment, achieved by Mg/Al layered-double-hydroxide nanoshells (Mg/Al-LDH) with AZ-23 loaded inside and alendronate decorated outside. The pain-causing H⁺ is rapidly eliminated by the LDH, with neurogenesis inhibited by the antagonist AZ-23. As positive feedback, the decreased pain reverses the nerve-to-cancer Ca²⁺ crosstalk-related cell cycle, dramatically inhibiting tumor growth. All experiments confirm the improved pain threshold and enhanced tumor inhibition. The study may inspire multidisciplinary researchers to focus on cancer-nerve crosstalk for treating cancer and accompanied neuropathic diseases.

Pain Prevalence During Cancer Treatment: A Systematic Review and Meta-Analysis

CONTEXT

Pain is one of the most complex and prevalent symptoms in the cancer population. Despite the protective role of acute cancer-related pain, it is also an important predictor for the likelihood of developing chronic pain after cancer treatment.

OBJECTIVES

Since the last systematic review on pain prevalence rates during cancer treatment dates already from 2016, the aim of the present systematic review was to provide an overview of pain prevalence rates during cancer treatment since this previous review.

METHODS

A systematic search of the literature, including studies between 2014 and 2020, was conducted using the databases Pubmed, Embase, Scopus, Web of Science and Cochrane. Studies reporting pain prevalence rates during or within three months after curative cancer treatment was included. Title/abstract and full-text was screened double-blinded, followed by independent evaluation of the risk of bias. All prevalence rates were pooled within meta-analyses and a meta-regression was performed to clarify the amount of heterogeneity.

RESULTS

Of the 9052 studies, 12 studies were included in the meta-analysis of which 10 included breast cancer and two lung cancer patients. The pooled pain prevalence rate was 40% (95%CI 0.29-0.51), with a heterogeneity of 96%. Out of the meta-regression, only the covariate "method of pain measurement" significantly clarified the heterogeneity (P < 0.05), resulting in a residual heterogeneity of 94.88%.

CONCLUSION

Five years after the last systematic review published on this topic, pain is still very prevalent during cancer treatment. However, the pain prevalence rates were also very heterogeneous. These two findings emphasize the need for further research on the development of adequate pain assessment and pain management approaches during cancer treatment.

A Prospective, Real-World, Multinational Study of Naloxegol for Patients with Cancer Pain Diagnosed with Opioid-Induced Constipation-The NACASY Study

The Naloxegol Cancer Study (NACASY) was a multinational European study aimed to evaluate the 4-week safety and efficacy of naloxegol in a real-world setting in patients with cancer pain diagnosed with opioid-induced constipation. The primary safety endpoint was the incidence of adverse events leading to study discontinuation. We recruited 170 patients who received at least one dose of naloxegol (i.e., safety population). Out of 170 patients, 20 (11.8%, 95%CI 6.9-16.6) discontinued the study due to adverse events, and, of them, 12 (7.1%, 95%CI 3.2-10.9%) were study discontinuations due to naloxegol-related adverse events. From 76 patients subjects who had completed both 4 weeks of treatment and 28 days of the diary, 55 patients (72.4%, 95% CI 62.3-82.4%) were regarded as responders (i.e., showed ≥3 bowel-movements per week and an increase of ≥1 bowel-movement over baseline) to naloxegol treatment. The Patient Assessment of Constipation-Quality of Life Questionnaire total score and all its subscales improved from baseline to 4 weeks of follow up. Our findings support and provide new evidence about the beneficial effect of naloxegol in terms of improvement of constipation and quality-of-life in patients with cancer-related pain and opioid-induced constipation and show a safety profile consistent with previous pivotal and real-world studies.

Effects of Transcutaneous Electrical Nerve Stimulation on Pain and Chemotherapy-Induced Peripheral Neuropathy in Cancer Patients: A Systematic Review

Transcutaneous electrical nerve stimulation (TENS) is the usage of a mild electrical current through electrodes that stimulate nerves. Patients with malignancies experience pain and chemotherapy-induced peripheral neuropathy. A systematic review was performed to find research evaluating the effect of TENS on these two common symptoms decreasing the quality of life in cancer patients. PubMed, the Cochrane Central Register of Controlled Trials and EMBASE were searched. Original studies, namely randomized controlled trials, quasi-randomized controlled trials and controlled clinical trials, published between April 2007 and May 2020, were considered. The quality of the selected studies was assessed. Seven papers were incorporated in a qualitative synthesis, with 260 patients in total. The studies varied in terms of design, populations, endpoints, quality, treatment duration, procedures and follow-up period. Based on the results, no strict recommendations concerning TENS usage in the cancer patient population could be issued. However, the existing evidence allows us to state that TENS is a safe procedure that may be self-administered by the patients with malignancy in an attempt to relieve different types of pain. There is a need for multi-center, randomized clinical trials with a good methodological design and adequate sample size.

The Impact of Optimism on Cancer-Related and Postsurgical Cancer Pain: A Systematic Review

BACKGROUND

The impact of psychological factors on pain levels continues to be of interest throughout a cancer patient's journey. The relationship between pain and optimism has been described previously in patients with various diseases.

OBJECTIVES

We further investigated the effect of optimism on pain levels felt by patients diagnosed and living with cancer before and after surgery.

MATERIALS AND METHODS

The search strategy for relevant articles from inception through June 2020 included five databases. The main outcome of interest was the effect of optimism on cancer-related pain.

RESULTS

We identified 482 studies. After the full-text screening, seven articles meeting the inclusion criteria were included. Seven studies were analyzed and are included in the data table. Of the seven included articles, four articles described the association of optimism with cancer pain; four articles studied the relationship between optimism and chronic postsurgical pain (CPSP), and one article investigated optimism's relationship with acute postsurgical pain (APSP). All articles observed a negative correlation between optimism and pain levels.

CONCLUSION

Despite the differences in the pathophysiology of pain types investigated, and which stage of the patient's journey pain was experienced, all studies reported a negative association with the level of optimism and pain described by patients. Therefore, promoting and supporting psychological coping techniques, including optimism for cancer patients may decrease patients' suffering, increase their quality of life at different cancer stages, and reduce opioid use.

History and Epidemiology of Cancer Pain

Pain is indelibly associated with the cancer experience. A systematic review and meta-analysis indicate that the prevalence of cancer pain is 55% during anticancer treatment, 66.4% in advanced, metastatic, or terminal disease, and 39.3% after curative treatment.

Cancer Pain Syndromes

Pain from cancer can present in a multitude of ways. In this chapter, we will identify the types of cancer pain and their etiologies. Following this, we will explore how cancer pain can present as somatic pain, visceral pain, and neuropathic pain. We will explore the aspects of the history and physical examination that point to specific diagnoses of pain and how to appropriately treat each diagnosis appropriately. Finally, we will touch upon a phenomenon known as opioid neurotoxicity.

A Systematic Review of CheeZheng Pain Relieving Plaster for Musculoskeletal Pain: Implications for Oncology Research and Practice

BACKGROUND

Musculoskeletal pain is a common and debilitating condition for cancer patients. Existing therapies for these pain conditions have substantial limitations. To identify an integrative approach to pain management, we conducted a systematic review to evaluate the safety and efficacy of a Tibetan herbal-based topical agent, CheeZheng Pain Relieving Plaster (PRP), for the treatment of osteoarthritis (OA) pain.

METHODS

We extracted citations from PubMed and Chinese databases (CNKI, WanFang Data, and CQVIP). We included randomized clinical trials evaluating the effectiveness and safety of CheeZheng PRP compared to conventional OA pain treatments.

RESULTS

Twenty-two randomized clinical trials (n = 2556 participants) compared CheeZheng PRP against nonsteroidal anti-inflammatory drugs (11), glucosamine (2), intraarticular corticosteroid (2), hyaluronic acid injections (6), and acetaminophen (1). Ten studies found a statistically greater effectiveness (assessed by ≥30% reduction in symptom severity) of CheeZheng PRP in improving OA pain (measured by the Visual Analogue Scale), stiffness, and function compared to control. Ten studies reported that 4.8% of participants experienced application site skin irritation that resolved after discontinuing the plaster. Randomization was not sufficiently described in most studies, and no placebo-controlled trials were identified.

CONCLUSIONS

There is promising evidence for the safety and clinical effectiveness of CheeZheng PRP to treat OA; however, lack of placebo control and unclear descriptions of randomization increase the potential risk for bias. Future randomized, placebo-controlled trials are needed to establish the safety and efficacy of CheeZheng PRP for pain management in oncology settings.

Pain Management in Breast Cancer Patients: A Multidisciplinary Approach

Pain is a significant problem and is one of the most invalidating symptoms in breast cancer (BC) patients that would negatively affect the functional status and the Quality of Life (QoL). Pain management in BC patients requires thorough patient evaluation and critical assessment of pain. The actual cause for the pain must be recognized, so management can be tailored to each patient. This review aims to discuss various treatment modalities employed for effectively managing pain in BC patients.

Pharmacotherapy makes up the cornerstone of the management of pain in BC patients. Both opioid and non-opioid analgesics are utilized. The WHO recommends a method called “by the ladder” for managing pain in BC patients where analgesics are used in ascending order. In comprehensive pain management (CPM), non-pharmacologic therapies are gaining wide acceptance and popularity, including complementary and alternative medicine (CAM), procedural and psychosocial interventions. Procedural interventions are usually used in case of severe pain refractory to pharmacological therapy. Techniques, such as radiotherapy, neurectomy, and nerve blocks, are effective in managing cancer pain. However, CAM therapies in BC pain management need to be guided by enough scientific evidence, decision-making, and medical judgment of regulatory bodies.

BC pain management is based on careful routine pain assessments and appropriate patient evaluation both physically and psychologically. Pain control is one of the methods to improve the QoL of BC patients. Both pharmacological and non-pharmacological therapies are accessible to patients today, but they should be used with caution to minimize toxicity and increase effectiveness. The use of any pain management intervention should be based on proper scientific evidence and collective medical judgment.

Patient-Caregiver Treatment Preference Discordance and Its Association With Caregiving Burden and Esteem

Background and Objectives

Many patient–caregiver dyads report conflicting treatment decisions regarding preferences for life extension treatments and symptom management. It is possible that this discordance will lead to negative psychological outcomes including lowered caregiving esteem and increased caregiver burden. However, the relationships between treatment discordance among dyads and caregiver psychological outcomes are not well studied among advanced cancer patients—a gap this study aims to fill.

Research Design and Methods

Outcome variables included caregiver burden and caregiving esteem, measured via a modified 4-domain Caregiver Reaction Assessment Scale. The main independent variable was patient–caregiver treatment preference discordance, examined using questions adapted from an existing protocol. Analyses were conducted using multivariable regressions.

Results

A convenience sample of 285 patient–caregiver dyads were recruited from outpatient clinics at 2 tertiary hospitals in Singapore. The majority (60%) of patient–caregiver dyads reported discordant treatment preferences. Discordance in this study arose because caregivers wanted a balance between life extension and symptom management while patients preferred life-extending treatment. In multivariable analyses, discordance predicted caregiver burden arising from impact on caregiver schedule and health (β = 0.16, p = .07) and lack of family support (β = 0.13, p = .04).

Discussion and Implications

Theoretically, this study provided a more nuanced understanding of how dyad discordance may worsen the burdens felt by caregivers, and which aspects of their lives (i.e., burden due to impact of caregiver schedule and health and lack of family support) are most affected. Our findings can aid in establishing therapeutic interventions targeted toward improving communication skills and encouraging end-of-life discussions among patients, caregivers, and their health care providers. The importance of establishing and improving therapy programs specifically targeted toward caregivers was also underlined.

Anesthetic considerations in patients with implantable devices and chronic pain surgery

The use of advanced invasive techniques for the control of chronic pain in patients with multiple comorbidities is becoming increasingly common. Neuromodulation offers a new management alternative involving the infusion of one or more drugs into the epidural or intrathecal space through a fully implantable infusion pump. It also involves spinal stimulation, a minimally invasive technique in which electrodes are positioned in the epidural space and connected to a pulse generator that is implanted subcutaneously and generates pulses designed to suppress the noxious stimulus. This article will describe the anesthetic considerations in cases of implantable drug delivery systems, and spinal and peripheral nerve stimulation devices. Additionally, patients with electrical or drug neuromodulation devices may present to anesthetic practice for surgical indications unrelated to their chronic pain pathology. Hence the importance of being familiar with the basic components of these devices, how they work, what drugs they use and the potential associated complications in the perioperative context, in order to ensure proper management and patient safety.

Clinical efficacy and implementation issues of an electronic pain reporting device among outpatients with cancer

PURPOSE

Collecting patients' pain features for congruent pain relief treatment is time-consuming. We sought to identify implementation issues and evaluate the efficacy of an electronic patient self-reporting pain device in community-based cancer clinics.

METHODS

In a 2-phase descriptive pilot and randomized controlled trial (RCT) with pretest/posttest design, 178 cancer patients participated (n = 33 pilot phase; n = 145 in the RCT phase). Patients completed PAINReportIt®, an electronic version of the valid and reliable McGill Pain Questionnaire that comprehensively measures the multiple dimensions of pain. All pilot phase and RCT patients were asked to complete PAINReportIt® twice and received usual care. For RCT patients assigned to the experimental group, a copy of the PAINReportIt® Summary was placed in their clinic medical record before they visited their clinicians. Posttest measures were completed 3-7 days later.

RESULTS

We identified three implementation barriers: system resistance to deposit of research data into the medical record, staff resistance to change, and patients' physical manipulation of the tablet. The time required to complete the tool did not differ significantly between groups but reduced significantly pre- to posttest in both RCT groups. Current pain intensity and pain quality but not worst pain scores decreased significantly pre- to posttest in the experimental group. None of the pain variables differed significantly between groups.

CONCLUSION

Implementation of PAINReportIt® was feasible in community oncology clinic settings. Barriers identified were expected and were surmountable. The studied tool showed satisfactory time sparing for comprehensive pain assessment with data automatically recorded and easily accessed by the clinician in the form of a summary report. Findings support the need for additional research to demonstrate the clinical efficacy of tablet-based pain assessment on patient outcomes as well as clinical care processes such as pain documentation and analgesic prescriptions.

Neurophysiological Mechanisms Related to Pain Management in Bone Tumors

BACKGROUND

Primary and metastatic bone tumor incidence has increased in the previous years. Pain is a common symptom and is one of the most important related factors to the decrease of quality of life in patients with bone tumor. Different pain management strategies are not completely effective and many patients afflicted by cancer pain cannot be controlled properly. In this sense, we need to elucidate the neurophysiology of cancer-induced pain, contemplating other components such as inflammation, neuropathies and cognitive components regarding bone tumors, and thus pave the way for novel therapeutic approaches in this field.

AIM

This study aims to identify the neurophysiology of the mechanisms related to pain management in bone tumors.

METHODS

Advanced searches were performed in scientific databases: PubMed, ProQuest, EBSCO, and the Science Citation index to get information about the neurophysiology mechanisms related to pain management in bone tumors.

RESULTS

The central and peripheral mechanisms that promote bone cancer pain are poorly understood. Studies have shown that bone cancer could be related to neurochemicals produced by tumor and inflammatory cells, coupled with peripheral sensitization due to nerve compression and injury caused by tumor growth. The activity of mesolimbic dopaminergic neurons, substance P, cysteine/ glutamate antiporter, and other neurochemical dynamics brings us putative strategies to suggest better and efficient treatments against pain in cancer patients.

CONCLUSION

Cancer-induced bone pain could include neuropathic and inflammatory pain, but with different modifications to the periphery tissue, nerves and neurochemical changes in different neurological levels. In this sense, we explore opportunity areas in pharmacological and nonpharmacological pain management, according to pain-involved mechanisms in this study.

Attitudes and appropriateness of pain management in cancer patients using pain management index

Objectives

Inadequate management of cancer pain (CP) remains a global medical problem. In this study, the aim was to assess attitudes of cancer patients towards their CP treatment and to evaluate effectiveness of pain management.

Methods

A sample of 300 adult cancer patients admitted to a single hospital were face-to-face interviewed in a cross-sectional study design using a structured questionnaire. The short form of the Brief Pain Inventory was used to collect data on pain, and Pain Management Index (PMI) was calculated to assess adequacy of pain management.

Key findings

Median age of patients was 53 years (interquartile range, 43–63). Half of patients (50.5%) believed their pain therapy needs improvement. Almost half patients had severe pain at interview (49.8%). Pain interfered most with patient enjoyment of life with a mean interference score 6.13 ± 2.37. Majority of cancer patients (84.3%) received a non-opioid analgesic while a minority (15.7%) received opioid analgesic in which morphine was the most common drug. The use of non-opioid adjuvants was minimal. Mean PMI for patients was −1.15 ± 0.75 (range −2 to +1), and most patients (80.3%) had inadequate pain treatment. Gender and smoking status of patients were significantly associated with adequacy of pain management (P = 0.009 and P = 0.004, respectively). There were no associations between patient age, educational level or tumour characteristics and adequacy of pain management.

Conclusions

Cancer patients in this study present with severe pain and the rates of undertreatment are high. There is an urgent need to improve management plans to assure appropriate use of therapeutic modalities for treatment of cancer-related pain.

[Radiosurgical hypophysectomy in cancer pain treatment. Literature review and clinical case]

Cancer pain is one of the main problem in modern medicine. According European Society for Medical Oncology data, cancer pain prevalence is 64% among patient with terminal stage of disease and in 46% standard pain therapy was ineffective. Radiosurgical hypophysectomy is one of the important and perspective method in cancer pain treatment. This method could be offered patient with chronic disease. According literature review, endocrinology complications were very rare and occurred 10 months after therapy. Value of analgesic effect was 70-90%. In some trials, procedure was effective not only nociceptive, but also in neuropathic pain. More trials require for determination of indications and mechanism of action. The case of successful relief of resistant pain in patient with pancreatic cancer by means of radiosurgical hypophysectomy is described.

Patients' Self-Assessment of the Symptoms and Impact of Opioid-Induced Constipation: Results From a Prospective Observational Cohort Study of Japanese Patients With Cancer

CONTEXT

Many patients who have cancer consider opioid-induced constipation (OIC) to be a burdensome side effect of opioid treatment.

OBJECTIVES

To evaluate patient-reported outcomes in Japanese patients with cancer pain and OIC.

METHODS

This prospective observational study evaluated OIC incidence for two weeks in patients with cancer after they initiated strong opioid therapy. Rome IV diagnostic criteria, a physician's diagnosis, spontaneous bowel movements, Bowel Function Index score, and patients' daily self-assessments were used. Changes from baseline in Patient Assessment of Constipation Symptoms and Patient Assessment of Constipation Quality of Life (PAC-QOL) scores were compared between patients with and without OIC. Patients and health care providers (HCPs) completed study-specific questionnaires regarding OIC burden, treatment satisfaction, and patient-provider communications.

RESULTS

Among 212 enrolled patients, the incidence of OIC was 47.6% by patients' self-assessments, with a cumulative incidence of 30.2% by Day 3 and 43.5% by Day 7. Patient Assessment of Constipation Symptoms and PAC-QOL overall scores from patients with OIC worsened significantly from baseline compared with patients without OIC by all diagnostic criteria, except for spontaneous bowel movement frequency for PAC-QOL. Patients and HCPs were generally satisfied with OIC treatment; however, 53.5% of patients and approximately 40.0% of HCPs reported that OIC affected pain management. Most patients and HCPs reported that OIC conditions were sufficiently or essentially communicated.

CONCLUSION

After starting opioid therapy, patients recognized OIC onset and its impact on cancer pain management, highlighting the need for effective patient-provider communications, diagnosis, and treatment of OIC to improve QOL for patients with cancer receiving opioid analgesics.

Managing Pain in People with Cancer-a Systematic Review of the Attitudes and Knowledge of Professionals, Patients, Caregivers and Public

Cancer pain is a common symptom experienced by patients, caused either by the disease or its treatment. Morphine remains the most effective and recommended treatment for cancer pain. However, cancer patients still do not receive appropriate management for their pain, and under-treatment is common. Lack of knowledge and negative attitudes towards cancer pain and analgesia among professionals, patients and family caregivers are reported as one of the most common barriers to effective cancer pain management (CPM). To systematically review research on the nature and impact of attitudes and knowledge towards CPM, a systematic literature search of 6 databases (the Cochrane library, MEDLINE, PsycINFO, CINAHL, Web of Science and EMBASE) was undertaken in July 2018. Additionally, hand-searching of Google, Google Scholar and reference lists was conducted. The inclusion criteria were adult (18-65 years of age), studies which included attitudes and knowledge towards CPM, studies written in English, published literature only and cross-sectional design. Included studies were critically appraised by two researchers independently using the Joanna Briggs Institute Analytical Cross Sectional Studies Assessment (JBI-ACSSA). A total of 36 studies met the inclusion criteria. The main finding was that among professionals, patients, caregivers and the public there were similar attitudinal barriers to effective CPM. The most commonly cited barriers were fear of drug addiction, tolerance of medication and side effects of opioids. We also found differences between professional groups (physicians versus nurses) and between different countries based on their potential exposure to palliative care training and services. There are still barriers to effective CPM, which might result in unrelieved cancer pain. Therefore, more educational programmes and training for professionals on CPM are needed. Furthermore, patients, caregivers, and the public need more general awareness and adequate level of knowledge about CPM.

Radiation Therapy Pain Management: Prevalence of Symptoms and Effectiveness of Treatment Options

BACKGROUND

The prevalence of pain among patients undergoing radiation therapy (RT) is not well described.

OBJECTIVES

The purpose of this study was to assess the prevalence and management of pain in patients undergoing RT.

METHODS

94 patients undergoing RT were surveyed at two time points during the course of their treatment. Patients reported on pain, fatigue, nausea, headache, and depressive symptoms, as well as on the use of pharmacologic and nonpharmacologic or alternative methods for symptom management.

FINDINGS

The mean severity of pain did not change significantly between the first week of RT and the final week. Severity of pain was associated with worse fatigue, nausea, headaches, and depressive symptoms, providing opportunities for providers to address multiple co-occurring symptoms. Rates of opioid and marijuana use remained similar between the two time points. More than half of the patients reported use of at least one nonpharmacologic method for pain management, with use increasing during the course of RT.

Molecular Basis of Cancer Pain Management: An Updated Review

Pain can have a significantly negative impact on the quality of life of patients. Therefore, patients may resort to analgesics to relieve the pain. The struggle to manage pain in cancer patients effectively and safely has long been an issue in medicine. Analgesics are the mainstay treatment for pain management as they act through various methods on the peripheral and central pain pathways. However, the variability in the patient genotypes may influence a drug response and adverse drug effects that follow through. This review summarizes the observed effects of analgesics on UDP-glucuronosyl (UGT) 2B7 isoenzyme, cytochrome P450 (CYP) 2D6, μ-opioid receptor μ 1 (OPRM1), efflux transporter P-glycoprotein (P-gp) and ATP-binding cassette B1 ABCB1/multiple drug resistance 1 (MDR1) polymorphisms on the mechanism of action of these drugs in managing pain in cancer. Furthermore, this review article also discusses the responses and adverse effects caused by analgesic drugs in cancer pain management, due to the inter-individual variability in their genomes.

Opioids in cancer-related pain: current situation and outlook

PURPOSE

Despite progress in treatments, cancer pain remains underestimated, poorly assessed and under-treated. Prescribing strong opioids, because of their specificities, requires precision in management considering their pharmacology but also a clear understanding of recommendations. Some clinicians highlight the risk of addiction, excessive sedation and respiratory depression and their need for information. Our objective in this review is to suggest some clinical guidance for the positioning and daily use of opioids within cancer pain management.

METHODS

Critical reflection based on literature analysis and clinical practice.

RESULTS

Strong opioids may be initiated as soon as pain diagnosis is defined. Factors to consider are pain aetiology, opioid pharmacokinetics and pharmacodynamics, genetic polymorphism, physiology (age, gender, weight and pregnancy), comorbidities (especially renal, hepatic, cardiovascular diseases), chronobiology, environmental factors, medication interference and treatment adherence. Achieving the best-balanced opioid treatment for background pain is complex, mainly due to the variable benefit/risk ratio between individuals and the experience of breakthrough cancer pain. Opioid initiation alongside a dynamic reassessment of pain should be fully integrated into the patient's management to optimise analgesia. The efficacy and safety of a strong opioid treatment need to be re-evaluated and adapted to individuals constantly as it varies over time.

CONCLUSIONS

Cancer pain is multimorphic and permanently changing due to disease evolution, curative treatments and disruptive events (concomitant treatments, pain from associated disease, comorbidities and complications, modifications of the environment). Well-managed opioids are the cornerstone of a complex environment requiring multidisciplinary dynamic assessments integrated into the patient's care pathway.

Strategies for interventional therapies in cancer-related pain-a crossroad in cancer pain management

PURPOSE

Interventional therapies are important to consider when facing cancer pain refractory to conventional therapies. The objective of the current review is to introduce these effective strategies into dynamic interdisciplinary pain management, leading to an exhaustive approach to supportive oncology.

METHODS

Critical reflection based on literature analysis and clinical practice.

RESULTS

Interventional therapies act on the nervous system via neuromodulation or surgical approaches, or on primitive or metastatic lesions via interventional radiotherapy, percutaneous ablation, or surgery. Interventional therapies such as neuromodulations are constantly evolving with new technical works still in development. Nowadays, their usage is better defined, depending on clinical situations, and their impact on quality of life is proven. Nevertheless their availability and acceptability still need to be improved. To start with, a patient's interdisciplinary evaluation should cover a wide range of items such as patient's performance and psychological status, ethical considerations, and physiochemical and pharmacological properties of the cerebrospinal fluid for intrathecal neuromodulation. This will help to define the most appropriate strategy. In addition to determining the pros and cons of highly specialized interventional therapies, their relevance should be debated within interdisciplinary teams in order to select the best strategy for the right patient, at the right time.

CONCLUSIONS

Ultimately, the use of the interventional therapies can be limited by the requirement of specific trained healthcare teams and technical support, or the lack of health policies. However, these interventional strategies need to be proposed as soon as possible to each patient requiring them, as they can greatly improve quality of life.

Opening up disruptive ways of management in cancer pain: the concept of multimorphic pain

PURPOSE

Following a series of articles reviewing the basics of cancer pain management, in this article, we develop the guiding principle of our philosophy: the concept of multimorphic pain and how to integrate it as the innovative cornerstone of supportive care in cancer.

METHOD

Critical reflection based on literature analysis and clinical practice.

RESULTS

This model aims to break with standard approaches, offering a more dynamic and exhaustive vision of cancer pain as a singular clinical entity, taking into account its multimorphic characteristics (cancer pain experience can and will change during cancer: aetiology, physiopathology, clinical presentation and consequences of pain) and the disruptive elements that can occur to influence its evolution (cancer evolution, concomitant treatments, pain from associated diseases, comorbidities and complications, or modifications in the environment). Our model establishes the main key stages for interdisciplinary management of cancer pain: Early, personalised management that is targeted and multimodal; Identification, including in advance, of potential disruptive elements throughout the care pathway, using an exhaustive approach to all the factors influencing pain, leading to patient and caregiver education; Optimal analgesic balance throughout the care pathway; Integration of this concept into a systemic early supportive care model from the cancer diagnosis.

CONCLUSIONS

Given the difficulties still present in the management of pain in cancer, and whilst cancer is often considered as a chronic condition, the concept of multimorphic pain proposes a practical, optimised and innovative approach for clinicians and, ultimately, for patients experiencing pain.

A clinical approach to the management of cancer-related pain in emergency situations

PURPOSE

Most cancer patients experience many pain episodes depending on disruptive elements, leading them to the emergency room. The objective of the article is to describe common pitfalls that need to be avoided, as well as opportunities to be seized for repositioning patients back on their care pathway.

METHODS

Critical reflection based on literature analysis and clinical practice.

RESULTS

Most forms of cancer are now chronic, evolving diseases, and patients are treated with high-technology targeted therapies with iatrogenic effects. Moreover, the multimorphic nature of cancer-related pain requires dynamic, interdisciplinary assessments addressing its etiology, its pathophysiology, its dimensions (sensory-discriminatory, cognitive, emotional, and behavioral), and the patient's perception of it, in order to propose the most adapted therapies. However, for most patients, cancer pain remains underestimated, poorly assessed, and under-treated. In this context, the key steps in emergency cancer pain management are as follows: • Quick relief of uncontrolled cancer pain: after eliminating potential medical or surgical emergencies revealed by pain, a brief questioning will make the use of carefully titrated morphine in most situations possible. • Assessment and re-assessment of the pain and the patient, screening specific elements, to better understand the situation and its consequences. • Identification of disruptive elements leading to uncontrolled pain, with an interdisciplinary confrontation to find a mid to long-term approach, involving the appropriate pharmaceutical and/or non-pharmaceutical strategies, possibly including interventions.

CONCLUSIONS

Pain emergencies should be part of the cancer care pathway and, through supportive care, provide an opportunity to help cancer patients both maintain their physical, psychological, and social balance and anticipate further painful episodes.

Strategies of complementary and integrative therapies in cancer-related pain-attaining exhaustive cancer pain management

PURPOSE

Complementary integrative therapies (CITs) correspond to growing demand in patients with cancer-related pain. This demand needs to be considered alongside pharmaceutical and/or interventional therapies. CITs can be used to cover certain specific pain-related characteristics. The objective of this review is to present the options for CITs that could be used within dynamic, multidisciplinary, and personalized management, leading to an integrative oncology approach.

METHODS

Critical reflection based on literature analysis and clinical practice.

RESULTS

Most CITs only showed trends in efficacy as cancer pain was mainly a secondary endpoint, or populations were restricted. Physical therapy has demonstrated efficacy in motion and pain, in some specific cancers (head and neck or breast cancers) or in treatments sequelae (lymphedema). In cancer survivors, higher levels of physical activity decrease pain intensity. Due to the multimorphism of cancer pain, certain mind-body therapies acting on anxiety, stress, depression, or mood disturbances (such as massage, acupuncture, healing touch, hypnosis, and music therapy) are efficient on cancer pain. Other mind-body therapies have shown trends in reducing the severity of cancer pain and improving other parameters, and they include education (with coping skills training), yoga, tai chi/qigong, guided imagery, virtual reality, and cognitive-behavioral therapy alone or combined. The outcome sustainability of most CITs is still questioned.

CONCLUSIONS

High-quality clinical trials should be conducted with CITs, as their efficacy on pain is mainly based on efficacy trends in pain severity, professional judgment, and patient preferences. Finally, the implementation of CITs requires an interdisciplinary team approach to offer optimal, personalized, cancer pain management.

Natural products as a perspective for cancer pain management: A systematic review

BACKGROUND

Cancer is the leading cause of death in the world and one of the main symptoms affecting these individuals is chronic pain, which must be evaluated and treated in its various components. Several drugs are currently used, but beyond the high cost, they have harmful side effects to patients or are transitorily effective. Ergo, there is a need to look for new options for cancer pain relief. Natural products (NPs) present themselves as strong candidates for the development of new drugs for the treatment of chronic pain, such as cancer pain.

PURPOSE

This systematic review aimed to summarize current knowledge about the analgesic profile of NPs in cancer pain.

METHODS

The search included PubMed, Scopus and Web of Science (from inception to June 2018) sought to summarize the articles studying new proposals with NPs for the management of oncological pain. Two independent reviewers extracted data on study characteristics, methods and outcomes.

RESULTS

After an extensive survey, 21 articles were selected, which described the analgesic potential of 15 natural compounds to relieve cancer pain. After analyzing the data, it can be suggested that these NPs, which have targets in central and peripheral mechanisms, are interesting candidates for the treatment of cancer pain for addressing different pharmacological mechanisms (even innovative), but ensuring the safety of these compounds is still a challenge. Likewise, the cannabinoids compounds leave the front as the most promising compounds for direct applicability due to the clinical studies that have already been developed and the background already established about these effects on chronic pain.

CONCLUSION

Regarding these findings, it can be concluded that the variability of possible biological sites of action is strategic for new perspectives in the development of therapeutic proposals different from those available in the current market.

Long-Term Opioid Therapy in Older Cancer Survivors: A Retrospective Cohort Study

OBJECTIVES

To examine the rates and predictors of long-term opioid therapy in older cancer survivors.

DESIGN

Retrospective cohort study.

SETTING

Texas, United States.

PARTICIPANTS

Cancer survivors (5 years or more postcancer diagnosis) diagnosed from 1995 to 2008 and who were also Medicare Parts A, B, and D beneficiaries.

MEASUREMENTS

We used Medicare Part D event data to calculate the proportion of cancer survivors with a prolonged opioid prescription (90-day or more supply of opioids/year). Adjusted odds ratios were calculated to identify predictors of prolonged opioid prescribing. All analyses were repeated with a subcohort of opioid-naïve cancer survivors.

RESULTS

The rate of prolonged opioid therapy for cancer patients diagnosed in 2008 was 7.1% prior to cancer diagnosis; it rose to 9.8% within a year of cancer treatments, and to 13.3% at 5 years postdiagnosis. The rate at the sixth year varied by cancer sites: 19.4% in lung cancer and 9.6% in prostate cancer. Among opioid-naïve survivors, the rate increased from 1.4% to 7.1%, from 5 to 18 years postcancer diagnosis. Cancer survivors diagnosed in 2004 to 2008 had higher rates of opioid prescribing compared to those diagnosed in 1995 to 1998 and 1999 to 2003. Years since diagnosis, a later year of diagnosis, female sex, urban location, lung cancer diagnosis, disability as reason for Medicare entitlement, Medicaid eligibility, one or more comorbidity, and history of depression or drug abuse were predictors of prolonged opioid therapy. Among opioid-naïve cancer survivors, diagnosis in 2004 to 2008 was the strongest predictor, while a history of drug abuse was the strongest predictor for all the survivors.

CONCLUSION

The rates of prolonged opioid prescribing for older cancer survivors remained high at 5 or more years after cancer diagnosis. Our findings have potential to inform the development of clinical guidelines and public policy to ensure safer and more effective pain treatment in older cancer survivors. J Am Geriatr Soc 67:945-952, 2019.

Pain: Persistent postsurgery and bone cancer-related pain

The generation of neuropathic pain is a complex dynamic process. Factors involved include one or more dysregulated sensory neural pathways; dysregulated activity of specific neurotransmitters, synapses, receptors and cognitive and emotional neural circuits; and the balance between degenerative and regenerative neural events. Risk factors include age, sex, cognition, emotions, genetic polymorphism, previous or ongoing chronic pain conditions and the use of certain drugs. Intense pain experienced before, during and after surgery is a risk factor for the development of central sensitization with consequent persistent postsurgery neuropathic pain. Blockade of N-methyl-D-aspartate receptors with appropriate drugs during and immediately after surgery may prevent persistent postsurgical pain. Most cancers, but particularly malignant metastases in bone, can induce persistent pain. Local factors including direct damage to sensory nerve fibres, infiltration of nerve roots by cancer cells and algogenic biological agents within the microenvironment of the tumour bring about central sensitization of dorsal horn neurons, characterized by neurochemical reorganization with persistent cancer pain. In this article, the clinical features, pathogenesis and principles of management of persistent postsurgery pain and cancer pain are briefly discussed.

Activation of the P2X7 receptor in midbrain periaqueductal gray participates in the analgesic effect of tramadol in bone cancer pain rats

Background

Cancer pain is a well-known serious complication in metastatic or terminal cancer patients. Current pain management remains unsatisfactory. The activation of spinal and supraspinal P2X₇ receptors plays a crucial role in the induction and maintenance mechanisms of various kinds of acute or chronic pain. The midbrain periaqueductal gray is a vital supraspinal site of the endogenous descending pain-modulating system. Tramadol is a synthetic, centrally acting analgesic agent that exhibits considerable efficacy in clinically relieving pain. The purpose of this study was to determine whether the activation of P2X₇ receptor in the ventrolateral region of the periaqueductal gray (vlPAG) participates in the analgesic mechanisms of tramadol on bone cancer pain in rats. The bone cancer pain rat model was established by intratibial cell inoculation of SHZ-88 mammary gland carcinoma cells. The analgesic effects of different doses of tramadol (10, 20, and 40 mg/kg) were assessed by measuring the mechanical withdrawal threshold and thermal withdrawal latency values in rats by using an electronic von Frey anesthesiometer and radiant heat stimulation, respectively. Alterations in the number of P2X₇ receptor-positive cells and P2X₇ protein levels in vlPAG were separately detected by using immunohistochemistry and Western blot assay. The effect of intra-vlPAG injection of A-740003 (100 nmol), a selective competitive P2X₇ receptor antagonist, on the analgesic effect of tramadol was also observed.

Results

The expression of P2X₇ receptor in the vlPAG on bone cancer pain rats was mildly elevated, and the tramadol (10, 20, and 40 mg/kg) dose dependently relieved pain-related behaviors in bone cancer pain rats and further upregulated the expression of P2X₇ receptor in the vlPAG. The intra-vlPAG injection of A-740003 pretreatment partly but significantly antagonized the analgesic effect of tramadol on bone cancer pain rats.

Conclusions

The injection of tramadol can dose dependently elicit analgesic effect on bone cancer pain rats by promoting the expression of the P2X₇ receptor in vlPAG.

Hepatocellular cancer pain: impact and management challenges

Hepatocellular carcinoma (HCC) remains the most common primary liver malignancy. Pain comprises one of the most pervasive and troubling symptoms of HCC and may have severely negative effects on patient’s quality of life. Furthermore, because HCC frequently arises in the setting of cirrhosis, treating pain related to this malignancy poses a clinical challenge. This article summarizes manifestations of hepatocellular cancer pain, common obstacles to treatment, and practical HCC pain management.

Pain in pancreatic ductal adenocarcinoma: A multidisciplinary, International guideline for optimized management

Abdominal pain is an important symptom in most patients with pancreatic ductal adenocarcinoma (PDAC). Adequate control of pain is often unsatisfactory due to limited treatment options and significant variation in local practice, emphasizing the need for a multidisciplinary approach. This review contends that improvement in the management of PDAC pain will result from a synthesis of best practice and evidence around the world in a multidisciplinary way. To improve clinical utility and evaluation, the evidence was rated according to the GRADE guidelines by a group of international experts. An algorithm is presented, which brings together all currently available treatment options. Pain is best treated early on with analgesics with most patients requiring opioids, but neurolytic procedures are often required later in the disease course. Celiac plexus neurolysis offers medium term relief in a substantial number of patients, but other procedures such as splanchnicectomy are also available. Palliative chemotherapy also provides pain relief as a collateral benefit. It is stressed that the assessment of pain must take into account the broader context of other physical and psychological symptoms. Adjunctive treatments for pain, depression and anxiety as well as radiotherapy, endoscopic therapy and neuromodulation may be required in selected patients. There are few comparative studies to help define which combination and order of these treatment options should be applied. New pain therapies are emerging and could for example target neural transmitters. However, until better methods are available, management of pain should be individualized in a multidisciplinary setting to ensure optimal care.

The Regulatory Mechanisms and Therapeutic Potential of MicroRNAs: From Chronic Pain to Morphine Tolerance

Chronic pain, including cancer-related pain, is a pain condition often caused by inflammation or dysfunctional nerves. Chronic pain treatment poses a significant health care challenge, where opioids especially morphine are widely used and patients often develop tolerance over time with aggravated pain. microRNA (miRNA) is known to play important roles in regulating gene expressions in the nervous system to affect neuronal network plasticity related to algogenesis and the developing of morphine tolerance. In this article, we reviewed studies conducted in rodent animal models investigating the mechanisms of miRNAs regulation in chronic pain with different phenotypes and morphine tolerance. In addition, the potential of targeting miRNAs for chronic pain and morphine tolerance treatment is also reviewed. Finally, we point out the directions of the future research in chronic pain and morphine tolerance.

Understanding the Progression of Bone Metastases to Identify Novel Therapeutic Targets

Bone is one of the most preferential target site for cancer metastases, particularly for prostate, breast, kidney, lung and thyroid primary tumours. Indeed, numerous chemical signals and growth factors produced by the bone microenvironment constitute factors promoting cancer cell invasion and aggression. After reviewing the different theories proposed to provide mechanism for metastatic progression, we report on the gene expression profile of bone-seeking cancer cells. We also discuss the cross-talk between the bone microenvironment and invading cells, which impacts on the tumour actions on surrounding bone tissue. Lastly, we detail therapies for bone metastases. Due to poor prognosis for patients, the strategies mainly aim at reducing the impact of skeletal-related events on patients' quality of life. However, recent advances have led to a better understanding of molecular mechanisms underlying bone metastases progression, and therefore of novel therapeutic targets.