Mechanism-based cancer-pain therapy

Nociceptor neurons promote PDAC progression and cancer pain by interaction with cancer-associated fibroblasts and suppression of natural killer cells

The emerging field of cancer neuroscience has demonstrated great progress in revealing the crucial role of the nervous system in cancer initiation and progression. Pancreatic ductal adenocarcinoma (PDAC) is characterized by perineural invasion and modulated by autonomic (sympathetic and parasympathetic) and sensory innervations. Here, we further demonstrated that within the tumor microenvironment of PDAC, nociceptor neurons interacted with cancer-associated fibroblasts (CAFs) through calcitonin gene-related peptide (CGRP) and nerve growth factor (NGF). This interaction led to the inhibition of interleukin-15 expression in CAFs, suppressing the infiltration and cytotoxic function of natural killer (NK) cells and thereby promoting PDAC progression and cancer pain. In PDAC patients, nociceptive innervation of tumor tissue is negatively correlated with the infiltration of NK cells while positively correlated with pain intensity. This association serves as an independent prognostic factor for both overall survival and relapse-free survival for PDAC patients. Our findings highlight the crucial regulation of NK cells by nociceptor neurons through interaction with CAFs in the development of PDAC. We also propose that targeting nociceptor neurons or CGRP signaling may offer a promising therapy for PDAC and cancer pain.

GFAP palmitoylcation mediated by ZDHHC23 in spinal astrocytes contributes to the development of neuropathic pain

BACKGROUND

Cancer pain has a significant impact on patient's quality of life. Astrocytes play an important role in cancer pain signaling. The direct targeting of astrocytes can effectively suppress cancer pain, however, they can cause many side effects. Therefore, there is an urgent need to identify the specific signaling pathways or proteins involved within astrocytes in cancer pain as targets for treating pain.

METHODS

A neuropathic cancer pain (NCP) model was established by inoculating mouse S-180 sarcoma cells around the right sciatic nerve in C57BL/6 mice. Spontaneous persistent pain and paw withdrawal thresholds were measured using von Frey filaments. The NCP spinal cord dorsal horn (L4-L6) and mouse astrocyte cell line MA-C were used to study protein palmitoylation using acyl-biotin exchange, real-time polymerase chain reaction, ELISA, western blotting, and immunofluorescent staining.

RESULTS

In a cancer pain model, along with tumor growth, peripheral nerve tissue invasion, and cancer pain onset, astrocytes in the dorsal horn of the spinal cord were activated and palmitoyltransferase ZDHHC23 expression was upregulated, leading to increased palmitoylation levels of GFAP and increased secretion of inflammatory factors, such as (C-X-C motif) ligand (CXCL)10 (CXCL-10), interleukin 6, and granulocyte-macrophage colony-stimulating factor. These factors in turn activate astrocytes by activating the signal transducer and activator of transcription 3 (STAT3) signaling pathway. A competitive peptide targeting GFAP palmitoylations was designed to effectively alleviate morphine tolerance in cancer pain treatment as well as cancer pain signaling and inflammatory factor secretion.

CONCLUSIONS

In a rodent model, targeting GFAP palmitoylation appears to be an effective strategy in relieving cancer pain and morphine tolerance. Human translational research is warranted.

Neuropathic Pain in Cancer: What Are the Current Guidelines?

OPINION STATEMENT

Neuropathic cancer pain is experienced by 30-40% of patients with cancer. It significantly reduces quality of life and overall wellbeing for patients living with and beyond cancer. The underlying mechanisms of neuropathic pain in patients with cancer are complex and involve direct tumour involvement, nerve compression or infiltration, chemotherapy and/or radiotherapy-induced nerve damage, or post-surgical complications. It is crucial for healthcare professionals to assess and manage neuropathic cancer pain effectively. There is increasing recognition that standardisation of neuropathic pain assessment leads to tailored management and improved patient outcomes. Pain management strategies, including medication, interventional analgesia, physical and complementary therapy, can help alleviate neuropathic pain and improve the patient's comfort and quality of life.

Experiences of patients with advanced cancer coping with chronic pain: a qualitative analysis

OBJECTIVES

To gain insight into the perceptions, and beliefs of patients with advanced cancer coping with chronic pain and to identify their attitudes and demands on pain management.

METHODS

From July to September 2022, 17 patients with advanced cancer living with chronic pain were recruited from a tertiary cancer hospital in Hunan Province, China. Qualitative and semi-structured interviews were conducted individually, with 30-45 minutes for each. The Colaizzi 7-step analysis method in phenomenological research was used for data analysis.

RESULTS

The experience of pain acceptance by advanced cancer patients with chronic pain was summarized into four themes: pain catastrophizing (unable to ignore the pain, try various methods to relieve the pain, exaggerating pain perception, and lack of knowledge about proper pain management), rumination (compulsive rumination and worrying rumination), avoidance coping (situational avoidance and repressive avoidance) and constructive action (setting clear value goal and taking reciprocal action).

CONCLUSION

Most patients with advanced cancer had low pain acceptance and negative attitudes. Feeling helpless in the face of pain and suffering alone were their norm. Long-term negative emotions could lead to gradual depression and loss of hope for treatment, resulting in pain catastrophizing and persistent rumination. Nevertheless, a few patients accepted pain with positive attitudes. Medical professionals should pay more attention to the psychological status of advanced cancer patients with chronic pain, and employ alternative therapies, for example, cognitive behavioral therapy. More efforts are needed to reduce patients' pain catastrophizing, and promote their pain acceptance by a better understanding of pain through health education.

From pain to tumor immunity: influence of peripheral sensory neurons in cancer

The nervous and immune systems are the primary sensory interfaces of the body, allowing it to recognize, process, and respond to various stimuli from both the external and internal environment. These systems work in concert through various mechanisms of neuro-immune crosstalk to detect threats, provide defense against pathogens, and maintain or restore homeostasis, but can also contribute to the development of diseases. Among peripheral sensory neurons (PSNs), nociceptive PSNs are of particular interest. They possess a remarkable capability to detect noxious stimuli in the periphery and transmit this information to the brain, resulting in the perception of pain and the activation of adaptive responses. Pain is an early symptom of cancer, often leading to its diagnosis, but it is also a major source of distress for patients as the disease progresses. In this review, we aim to provide an overview of the mechanisms within tumors that are likely to induce cancer pain, exploring a range of factors from etiological elements to cellular and molecular mediators. In addition to transmitting sensory information to the central nervous system, PSNs are also capable, when activated, to produce and release neuropeptides (e.g., CGRP and SP) from their peripheral terminals. These neuropeptides have been shown to modulate immunity in cases of inflammation, infection, and cancer. PSNs, often found within solid tumors, are likely to play a significant role in the tumor microenvironment, potentially influencing both tumor growth and anti-tumor immune responses. In this review, we discuss the current state of knowledge about the degree of sensory innervation in tumors. We also seek to understand whether and how PSNs may influence the tumor growth and associated anti-tumor immunity in different mouse models of cancer. Finally, we discuss the extent to which the tumor is able to influence the development and functions of the PSNs that innervate it.

Cancer Pain Management with Traditional Chinese Medicine: Current Status and Future Perspectives

Cancer pain, especially the moderate-to-severe pain experienced by patients with advanced cancer, is still one of the most challenging clinical problems. The current mainstream pharmacological treatment for cancer pain involves applying opioid medications and other pain-killing drugs. However, analgesic drugs have many adverse effects such as addiction, tolerance, and other formidable clinical and social issues. Thus, finding a new therapeutic approach to treat cancer pain is essential. Traditional Chinese medicine (TCM) has been increasingly applied in clinical practice because of its good efficacy and few side effects. However, its mechanisms of action in treating pain are still under investigation. The most important mechanism of cancer pain is that a large amount of pain-causing substances are secreted from cancer cells and promote their growth and invasion. The physical and chemical stimulations of these substances exist along with the cancer growth, leading to constantly increased pain sensation. Whether cancer pain can be alleviated by inhibiting cancer cells from releasing the substances and changing the microenvironment around the cancer mass, or even by eliminating pain-causing substances, is largely unknown. Based on TCM theory, this study reported that the aforementioned approach could effectively manage different cancer pains by tonifying qi, clearing and activating channels and meridians, and strengthening body resistance. The TCM therapies activate blood circulation, remove blood stasis, and nourish the heart. Commonly used Chinese herbal drugs include Corydalis yanhusuo, Angelica dahurica, and Ligusticum chuanxiong. Instead of using conventional analgesics to reduce pain, we should focus on using TCM modalities to alleviate cancer pain and increase the quality of life in patients suffering from cancer pain. TCM should provide us with a new strategy for managing cancer pain.

Exploration of pain assessment and management processes in oncology outpatient services with healthcare professionals: a qualitative study

OBJECTIVES

This study explored cancer pain management practices and clinical care pathways used by healthcare professionals (HCPs) to understand the barriers and facilitators for standardised pain management in oncology outpatient services (OS).

DESIGN

Data were collected using semistructured interviews that were audio-recorded and transcribed. The data were analysed using thematic analysis.

SETTING

Three NHS trusts with oncology OS in Northern England.

PARTICIPANTS

Twenty HCPs with varied roles (eg, oncologist and nurse) and experiences (eg, registrar and consultant) from different cancer site clinics (eg, breast and lung). Data were analysed using thematic analysis.

RESULTS

HCPs discussed cancer pain management practices during consultation and supporting continuity of care beyond consultation. Key findings included : (1) HCPs' level of clinical experience influenced pain assessments; (2) remote consulting impeded experienced HCPs to do detailed pain assessments; (3) diffusion of HCP responsibility to manage cancer pain; (4) nurses facilitated pain management support with patients and (5) continuity of care for pain management was constrained by the integration of multidisciplinary teams.

CONCLUSIONS

These data demonstrate HCP cancer pain management practices varied and were unstructured. Recommendations are made for a standardised cancer pain management intervention: (1) detailed evaluation of pain with a tailored self-management strategy; (2) implementation of a structured pain assessment that supports remote consultations, (3) pain assessment tool that can support both experienced and less experienced clinicians. These findings will inform the development of a cancer pain management tool to integrate within routine oncology OS.

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.

End-of-life cancer patients' total pain: the necessity to supplement pharmacology with psycho-socio-spiritual treatments

Aim: To analyze pain considering its different bio-psycho-social-spiritual manifestations and to assess the effectiveness of the analgesic treatments in end-of-life cancer patients. Materials & methods: The study was cross-sectional. A total of 376 end-of-life cancer inpatients participated in the research. Their socio-demographic and clinical data were collected and, during the first psychological consultancy, they filled in a set of validated rating scales assessing pain, anxiety, depression and quality of life. Results: The results show that physical pain was well managed for almost all patients. Nevertheless, the majority showed clinically significant levels of psychological distress. Conclusion: Treating pain means caring for all its possible manifestations including psychological symptoms and reduced wellbeing. Thus, integrating pharmacological treatment with psycho-socio-spiritual interventions, in other words, psychological, social and spiritual support, could be effective and desirable.

Development of Anticancer Peptides with Low Hemolysis, High Penetrating Membrane Activity, Certain Analgesic Activity and the Synergistic Anticancer Effect

Herein, an amphiphilic cationic α-helical anticancer lipopeptide P10 with the low toxicity and high penetrating membrane activity was developed. The lipopeptide could self-assemble into stable spherical aggregates in aqueous solution,...

Phosphoproteomic Profiling of Rat's Dorsal Root Ganglia Reveals mTOR as a Potential Target in Bone Cancer Pain and Electro-Acupuncture's Analgesia

Bone cancer pain (BCP) is a clinical refractory mixed pain involving neuropathic and inflammatory pain, with the underlying mechanisms remaining largely unknown. Electro-acupuncture (EA) can partly alleviate BCP according to previous research. We aim to explore the proteins and major pathways involved in BCP and EA treatment through phosphoproteomic profiling. BCP rat model was built by tibial inoculation of MRMT-1 mammary gland carcinoma cells. Mechanical hyperalgesia determined by paw withdrawal thresholds (PWTs) and bone destruction manifested on the radiographs confirmed the success of modeling, which were attenuated by EA treatment. The differentially expressed phosphorylated proteins (DEPs) co-regulated by BCP modeling and EA treatment in rat dorsal root ganglions (DRGs) were analyzed through PEX100 Protein microarray. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that DEPs were significantly enriched in mammalian target of rapamycin (mTOR) signaling pathway. The phosphorylations of mTOR at Ser2448 and Thr2446 were increased in BCP and downregulated by EA. In addition, the phosphorylation of S6K and Akt, markers of the mTOR complex, were also increased in BCP and downregulated by EA. Inhibition of mTOR signaling alleviated the PWTs of BCP rats, while the mTOR agonist impaired the analgesic effect of EA. Thus, our study provided a landscape of protein phosphorylation changes in DRGs of EA-treated BCP rats and revealed that mTOR signaling can be potentially targeted to alleviate BCP by EA treatment.

The combined analgesic effect of pregabalin and morphine in the treatment of pancreatic cancer pain, a retrospective study

BACKGROUND

Pregabalin is commonly used to relieve neuropathic pain. However, data are lacking on its efficacy for the treatment of chronic cancer pain. The purpose of this study was to determine the analgesic efficacy of pregabalin combined with morphine in the management of pancreatic cancer pain.

METHODS

This study reviewed patients who were prescribed morphine and 150 mg/d pregabalin between 1 January 2017 and 10 November 2018 in our institute. The primary outcomes of this study were the average pain score and dose of morphine. Secondary outcomes included characters of breakthrough cancer pain, functional interference related to pain, anxiety/depression status, and incidence of treatment-related adverse events during the study.

RESULTS

A total of 240 patients with pain related to pancreatic cancer were included in the study. The results showed that patients of both combination therapy group (pregabalin+morphine) and monotherapy group (morphine) achieved similar analgesic efficacy, demonstrated by NRS (2.4 ± 0.9 vs. 2.6 ± 0.9; combination vs. monotherapy) at the end of the study. Mean daily dose of morphine used in the combination group was significant lower compared to monotherapy group (39.5 ± 16.0 mg vs. 61.5 ± 19.3 mg, net difference 23.5, 95% CI: 18.4-28.6, p <  0.001). The change of functional interference score related to pain was significantly different between combination and monotherapy group (12.0 ± 0.4 vs. 9.8 ± 4.9; net difference, 2.3; 95% CI: 1.1-3.3; p < 0.001). Patients in combination therapy group had experienced shorter duration of breakthrough cancer pain than those in monotherapy group (X² p < 0.001, Cramer's V:0.36). The incidence of somnolence, dizziness, and cognitive dysfunction were significantly higher in the combination group compared to monotherapy group. No serious treatment-related side effects were observed.

CONCLUSIONS

The findings of this study supported the use of pregabalin with morphine to relieve pain in patients of pancreatic cancer.

Management of Procedural Pain in Children

In recent years, there has been increased interest in the study of pain in children and its treatment. It is known that when facing diagnostic and therapeutic procedures similar to those performed on adults, children either do not receive specific pain treatment or receive it on a significantly lower scale. However, recent research suggests a change in attitude and an improvement in the current treatment of children's pain. Although current knowledge demonstrates the falsity of many preconceived ideas about pain and its management, our results suggest that attitudinal change towards childhood pain remains slow and that real improvement in the training and practical application of the pediatrician who has to treat childhood pain is urgently needed. In this context, this manuscript has prepared standards and guidelines to improve pain management practices in a large number of national and international professional settings.

Reasons for failure to perform interventional pain procedures in cancer patients: an analysis of pain clinic consultations

Background

Interventional pain procedures (IPPs) may be necessary for some cancer patients when conservative treatment fails. However, many IPPs are often delayed or cancelled for cancer patients who are referred to the pain clinic.

Methods

We retrospectively analyzed the reasons for such cancellations to identify clinically avoidable causes of the delay in IPP.

Results

We enrolled 350 cancer patients who were referred to our pain clinic for an IPP between March 2016 and February 2018. There were 213 (60.9%) cases that were cancelled, among which 115 (54%) cases were potentially avoidable and 98 (46%) were unavoidable. The most common reasons for cancellation were patient-derived factors, which accounted for 85 (39.9%) cases. Patient refusal was a common reason for cancellation, with 33 (15.5%) cases attributed to this cause. The primary avoidable causes of cancellation were a recommendation that the patient continue with their current pharmacological pain treatment, conflict with another planned treatment, and pain characteristics that were not suitable for an IPP. Together, these accounted for 76.5% of all avoidable cancellations.

Conclusions

Comprehensive and accurate pain assessments before IPP may result in more favorable outcomes for the efficient use of medical resource and effective pain relief in cancer patients.

Index and Nonindex Pain Endpoints in Radiation Therapy for Painful Tumors: A Secondary Analysis of a Prospective Observational Study

Purpose

Improving pain interference in daily activities, rather than mere pain reduction, is a desirable endpoint for palliative radiation therapy. The association between pain response and pain interference has been studied almost exclusively in patients with painful bone metastases (PBMs), whereas nonindex pain has scarcely been explored in palliative radiation therapy. We investigated whether index and nonindex pain endpoints are associated with pain interference changes in patients with both PBMs and painful non-bone-metastasis tumors (PNTs).

Methods and Materials

Brief pain inventory data collected at baseline and at 2 months post-treatment were used to calculate differences in pain interference scores. Pain response in terms of the index pain was assessed using the international consensus endpoint. Patients were diagnosed with predominance of other pain (POP) if nonindex pain of malignant or unknown origin was present and had a greater pain score than the index pain.

Results

Of 302 patients, 127 (42%) had PBMs and 175 (58%) had PNTs. The median pain interference score, which is based on the mean of the 7 subscale items, decreased to a greater extent among responders than among nonresponders (PBM group: –3.43 vs –0.57 [P = .005]; PNT group: –2.43 vs –0.29 [P < .001]). Moreover, patients without POP experienced a greater reduction in their median pain interference score than did those with POP (PBM group: –2.71 vs +0.43 [P = .004]; PNT group: –2.00 vs +1.57 [P = .007]). The Jonckheere-Terpstra test showed a significant trend across 4 pain response categories in patients with PBMs and those with PNTs (P < .001 for both).

Conclusions

The index and nonindex pain endpoints were positively and negatively associated with improvement in pain interference, respectively. There was no apparent difference between patients with PBMs and PNTs in terms of the associations of these endpoints with pain interference.

A simple mechanistic terminology of psychoactive drugs: a proposal

Antidepressants, antiepileptics, mood stabilizers, and antipsychotics are extremely broadly used psychoactive drugs. These drug terms are universally used in the literature. However, the indications of these drugs have broadened substantially and overlap. The mismatch between drug classification and clinical uses causes a lot of confusion in communication and renders literature searches increasingly difficult. Therefore, we propose to drop the above terms altogether and replace them by simple mechanistic terms. Antidepressants are re-named as norepinephrine/serotonin (NE/5-HT) enhancers, antiepileptics comprising drugs with different mechanisms become neuronal inhibitors with pleiotropic effects (NIPEs), and antipsychotics become antagonists at multiple G protein-coupled receptors (mGPCR antagonists). Alkali metal ions, comprising lithium, are integrated into NIPEs. The terms "typical/first-generation/conventional" and "atypical/second-generation/non-conventional" antipsychotics should be dropped, because the original criterion for distinction, i.e., the presence and absence of extrapyramidal motor effects, respectively, is not valid anymore. The suggested changes in drug nomenclature have already been implemented into a recent textbook (Seifert R, Basic Knowledge of Pharmacology). The revised nomenclature ensures consistency with other fields of pharmacology and assignment of drug classes to indications without causing confusion. The authors acknowledge that the change in drug nomenclature is a cultural process that will take time and openly discuss the problems associated with the proposal. Ultimately, international learned societies will have to agree on a new nomenclature.

Fentanyl inhibits the progression of gastric cancer through the suppression of MMP-9 via the PI3K/Akt signaling pathway

BACKGROUND

Fentanyl is a drug commonly used for perioperative and postoperative analgesia. Previous studies have confirmed that fentanyl can affect the progression of gastric cancer; however, this effect has not yet been elucidated. The purpose of our study was thus to investigate the role of fentanyl in gastric cancer and clarify its potential mechanisms.

METHODS

A CCK-8 assay was used to determine the proliferation of MGC-803 cells, while Transwell assay and wound healing assay were used to determine the invasion and migration abilities, respectively. Apoptosis and the cell cycle were assessed by flow cytometry, and the ultrastructure of the cells was examined with a transmission electron microscope. The mRNA expression levels of serine-threonine protein kinase 1 (Akt-1), matrix metalloproteinase-9 (MMP-9), and death-associated protein kinase 1 (DAPK1) were evaluated by real-time (RT) quantitative PCR. The protein expression of p-Akt, MMP-9, and caspase-9 was detected by western blot analysis. To study the interaction of fentanyl with the phosphatidylinositol-3-kinase (PI3K)/Akt/MMP-9 pathway, PI3K inhibitor (LY294002) and MMP-9 inhibitor (SB-3CT) were used to treat the MGC-803 cells.

RESULTS

Findings indicated that fentanyl inhibits the proliferation, invasion, and migration of MGC-803 cells. Specifically, fentanyl inhibits the expression of MMP-9 and enhances the expression of apoptosis-promoting factors such as caspase-9 and DAPK1 through the PI3K/Akt signaling pathway. Cell cycle arrest was observed in the G0/G1 phase. Furthermore, the inhibition of PI3K/Akt/MMP-9 by LY294002 and SB-3CT enhanced the anticancer effects of fentanyl.

CONCLUSIONS

Fentanyl inhibits the proliferation, invasion and migration of gastric cancer cells by inhibiting the PI3K/Akt/MMP-9 pathway, which could be very useful for gastric cancer treatment.

Access to Opioids for Patients with Advanced Disease

Pain at the end of life is common in both malignant and non-malignant disease. It is feared by patients, their families and careers, and professionals. Effective pain control can be achieved for the majority of patients at the end of life using a multimodal approach. Pharmacological management relies predominantly on strong opioids. In spite of this, evidence suggests that under treatment of pain is common resulting in unnecessary suffering. Multiple barriers to use of opioids have been identified. Patient barriers include reluctance to report pain and to take analgesics. Professional barriers include inadequate pain assessment and lack of specialist knowledge and confidence in opioid therapy. Fear of side effects including respiratory depression affects patients and professionals alike. The impact of the "opioid epidemic", with increasing prescribed and illicit opioid use around the world, has also led to increasingly stringent regulation and concern about under prescribing in palliative care. System barriers to use of opioids at the end of life result from limited opioid availability in some countries and also inconsistent and limited access to palliative care. Multiple interventions have been developed to address these barriers, targeted at patients, professionals and systems. There is increasing evidence to suggest that complex interventions combining a number of different approaches are most effective in optimising pain outcomes for patients at the end of life.

Cancer-Related Neuropathic Pain

Neuropathic pain in cancer is common and debilitating. It is important to differentiate neuropathic pain from other cancer-related pains as it is associated with worse pain outcomes and requires different treatment strategies. This review summarises recent updates to pain classification, aetiology, pain assessment and current recommendations for treatment in patients with cancer-related neuropathic pain.

Standards for the management of cancer-related pain across Europe-A position paper from the EFIC Task Force on Cancer Pain

BACKGROUND AND OBJECTIVE

Pain is a common symptom in patients who survive cancer and in those who live with progressive advanced disease. Evidence from meta-analyses suggests that pain remains poorly controlled for a large proportion of patients; barriers to good management include poor assessment of pain, inadequate support for patient self-management and late or inadequate access to strong opioid analgesia in those with advanced disease.

METHODS

The European Pain Federation (EFIC) established a Task Force in 2017 which convened a European group of experts, drawn from a diverse range of relevant clinical disciplines, to prepare a position paper on appropriate standards for the management of cancer-related pain. The expert panel reviewed the available literature and made recommendations using the GRADE system to combine quality of evidence with strength of recommendation. The panel took into account the desirable and undesirable effects of the management recommendation, including the cost and inconvenience of each when deciding the recommendation.

RESULTS AND CONCLUSIONS

The 10 standards presented are aimed to improve cancer pain management and reduce variation in practice across Europe. The Task Force believes that adoption of these standards by all 37 countries will promote the quality of care of patients with cancer-related pain and reduce unnecessary suffering.

SIGNIFICANCE

Pain affects up to 40% of cancer survivors and affects at least 66% of patients with advanced progressive disease, many of whom experience poor pain control. These 10 standards are aimed to improve cancer pain management, promote the quality of care of patients and reduce variation across Europe.

Improvement in pain interference after palliative radiotherapy for solid and hematologic painful tumors: a secondary analysis of a prospective observational study

Background

We previously demonstrated that patients with painful hematologic tumors were more likely to experience pain response after palliative radiotherapy (RT) than those with painful solid tumors. However, it is unknown whether change in pain interference differs between these two tumor types. In the present study, we carried out a secondary analysis of our previous prospective observational study to investigate this matter.

Methods

From patients undergoing palliative RT to treat painful tumors, Brief Pain Inventory data were collected at the start of RT and at the 1-, 2-, and 3- month follow-ups. The Mann-Whitney U test was used to compare changes in pain interference score from baseline between the two groups.

Results

Of the 237 patients, 203 (86%) had solid and 34 (14%) had hematologic index tumors planned to receive RT. At baseline, the groups did not differ significantly in terms of pain score, analgesic use, or pain interference score. At the 1-, 2-, and 3-month follow-ups, the changes in pain interference score from baseline did not differ significantly between the two groups. In both groups, all seven pain interference items, other than sleep in patients with hematologic tumors at the 2-month follow-up, were significantly improved (P < 0.05).

Conclusions

The two groups showed comparable benefit from RT in terms of improvement in pain interference. Patients with tumor-related pain should be offered the option of palliative RT, irrespective of whether the painful tumor is solid or hematologic.

A neuropathic pain component as a predictor of improvement in pain interference after radiotherapy for painful tumors: A secondary analysis of a prospective observational study

•

A neuropathic component was related to worse pain interference scores at baseline.

•

A neuropathic component predicted a greater reduction in pain interference.

•

Older patients and male patients tended to have a neuropathic component.

Background and purpose

We previously demonstrated that patients with a tumor-related neuropathic pain component were more likely to experience a pain response after radiotherapy (RT) than those without. It is unknown whether the presence of a neuropathic component also favorably influences pain interference. In a secondary analysis of our previous prospective observational study, we investigated if the presence of a neuropathic component of the index pain caused by the irradiated tumors predicts greater reduction in pain interference.

Material and methods

For patients scheduled for RT for painful tumors, Brief Pain Inventory data were collected at initiation of RT and 1, 2, and 3 months thereafter. Multivariable linear regression analyses were performed to investigate the effects of the presence of a neuropathic component on the changes in pain interference scores (i.e., follow-up minus baseline). We used 10 covariates as potential confounders.

Results

Of the 302 analyzable patients, 93 (31%) were diagnosed as having a neuropathic component of the index pain. Multivariable linear regression analyses revealed that all the point estimates of regression coefficients at 1-, 2-, and 3-month follow-up were negative values; some were statistically significant. At 2-month follow-up, patients with a neuropathic component experienced greater reductions in their pain interference scores for walking ability (p = 0.048), normal work (p = 0.021), sleep (p = 0.001), and enjoyment of life (p = 0.010) than those without it.

Conclusions

The presence of a neuropathic pain component predicted a greater reduction in pain interference after RT. Patients with neuropathic tumor-related pain should be offered the option of receiving palliative RT.

Cancer Pain With a Neuropathic Component: A Cross-sectional Study of Its Clinical Characteristics, Associated Psychological Distress, Treatments, and Predictors at Referral to a Cancer Pain Clinic

CONTEXT

In patients with cancer pain, identifying a neuropathic pain component (NPC) may inform the selection of subsequent therapeutic interventions.

OBJECTIVES

The objective of this study was to determine the prevalence, clinical characteristics, associated psychological distress, pre-referral treatment, and predictors of cancer pain with an NPC in patients referred to a cancer pain clinic.

METHODS

Participants had standard assessments and documentation: Brief Pain Inventory ratings, presence of an NPC, based on a Douleur Neuropathique 4 (DN4) (neuropathic pain screening scale) score ≥4 combined with a physician's clinical assessment (blinded to DN4 result), the Hospital Anxiety Depression Scale, and Emotion Thermometer scores. Logistic regression analyses were used to determine predictors associated with an NPC.

RESULTS

Of 371 study participants, 120 (32.3%) had a designated NPC. Overall, psychological distress indices were similar in the NPC and nociceptive pain groups, except for a Hospital Anxiety and Depression Scale >7 score that was proportionately higher (74% vs. 63%, P = 0.03) in the nociceptive group. The final multivariable logistic regression model generated the following NPC predictors and their respective odds ratios (95% CIs): recent chemotherapy, 2.93 (1.63-5.26); recent surgery, 3.65 (2.03-6.59); adjuvant analgesic use, 2.93 (1.66-5.17); episodic incident pain, 2.63 (1.44-4.84); episodic breakthrough pain, 3.67 (2.00-6.73); pain duration three or more months, 2.35 (1.36-4.06); higher pain intensity, 1.47 (1.24-1.74); and pelvic or perineal pain location, 2.75 (1.09-6.96).

CONCLUSION

One in three patients with cancer have an NPC, which is independently associated with recent chemotherapy, surgery, adjuvant analgesic use, episodic incident and breakthrough pain, longer pain duration, higher pain intensity, and pelvic or perineal pain location.