Efficacy and Safety of Different Acupuncture Treatments for Cancer-Related Pain: A Systematic Review and Network Meta-Analysis

BACKGROUND

Cancer pain is a prevalent and persistent issue, and while there have been some observations of the possible benefits of acupuncture in managing cancer pain, there is still debate regarding its safety and effectiveness. This study aims to compare the efficacy and safety of different acupuncture modalities in the treatment of cancer pain through a network meta-analysis.

METHODS

Between the time each database was created and June 3, 2024, eight databases were queried: PubMed, Cochrane, Embase, Web of Science, CNKI, Wanfang, VIP, and China Biomedicine. Randomized controlled trials investigating the use of various acupuncture and moxibustion techniques in the treatment of cancer pain were identified. Publication bias and quality of randomized controlled trials were assessed using the Cochrane Risk of Bias tool and the Jadad scale, and network meta-analyses were performed using Stata 15 and R 4.3.2.

RESULTS

We incorporated 111 studies encompassing 9549 individuals diagnosed with cancer, examining 29 distinct therapies. Network meta-analysis showed that, compared to Usual Medicine, Acupuncture + Usual Medicine + Traditional Chinese medicine (MD = -1.83, 95% CI: -2.86 to -0.80) could reduce NRS scores, Acupuncture + Traditional Chinese medicine (OR = 30.86, 95% CI: 3.75-254.20) could improve cancer pain relief, Moxibustion + Usual Medicine (MD = 2.12, 95% CI: 0.43-3.80) could effectively improve KPS score, Acupuncture + Application of Chinese medicine (OR = 0.16, 95% CI: 0.04-0.66) is associated with a lower incidence of constipation, Electro-Acupuncture + Usual Medicine (OR = 0.11, 95% CI: 0.03-0.45) shows a lower incidence of nausea and vomiting, Acupuncture + Moxibustion + Usual Medicine (OR = 0.29, 95% CI: 0.09-0.90) is associated with a lower incidence of dizziness.

CONCLUSION

Acupuncture + Traditional Chinese medicine is the best intervention for different acupuncture methods in the treatment of cancer pain, and Moxibustion + Usual Medicine is the best intervention to improve the quality of life of patients.

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.

Pain experience of cancer patients receiving care in a multidisciplinary pain management clinic

BACKGROUND

Few longitudinal studies have focused on patients' cancer pain experience when receiving care in a multidisciplinary pain management clinic (MPMC). This study aimed to evaluate the experiences of a cohort of cancer patients newly engaged in a MPMC.

METHODS

This study was based on a longitudinal approach in which data were collected over a 6 months period at the King Hussein Cancer Centre in Jordan. The study adopted the Arabic version of the Brief Pain Inventory to identify the level and prevalence of cancer pain, and to identify the impact of receiving care at the MPMC on patients' pain experience. Data were collected over four time points, and the period between these points ranged from 2 to 3 weeks.

RESULTS

The majority of patients demonstrated improvement in their pain after receiving treatment at the MPMC, while a third still experienced severe pain. Significant improvement was reported at T1, and no further decline in pain was noted after this point. This indicates that exposure to the intervention provided by the MPMC generated, on average, an improvement in patients' pain experience.

CONCLUSION

The MPMC may be an effective pain management strategy in the treatment of cancer pain.

Moxibustion as an Adjuvant Therapy for Cancer Pain: A Systematic Review and Meta-Analysis

Purpose

Pain is one of the most common and feared symptoms among cancer patients. Unrelieved pain denies patients comfort and greatly affects their overall quality of life. Moxibustion is commonly used to manage chronic pain. However, its efficacy on cancer pain remains inconclusive. This study aimed to evaluate the efficacy of moxibustion for cancer pain.

Methods

We searched seven databases to obtain articles about moxibustion combined with pharmacotherapy for cancer pain published before November 2022. All data extraction was carried out independently by two investigators. RevMan 5.4 software was used for data analysis.

Results

A total of ten trials involving 999 cases were included. The results of the meta-analysis revealed that moxibustion combined with pharmacotherapy was significantly better than drug therapy alone in improving pain relief rate (RR =1.16, 95% CI = [1.04, 1.30], P = 0.01), reducing pain scores (SMD = -1.43, 95% CI = [-2.09, -0.77], P < 0.0001), Shortening the onset of analgesia (MD = -12.07, 95% CI = [-12.91, -11.22], P < 0.00001), prolonging the duration of analgesia (MD = 3.69, 95% CI = [3.21, 4.18], P < 0.00001), and improving quality of life (SMD = 2.48, 95% CI = [0.67, 4.29], P = 0.007). In addition, moxibustion combined with pharmacotherapy can effectively reduce adverse reactions of drugs (RR =0.35, 95% CI = [0.21, 0.57], P < 0.0001).

Conclusion

The evidence in this review supports moxibustion as an effective adjuvant therapy for cancer pain management. However, high-quality RCTs are needed to further confirm these findings.

Registration Number

PROSPERO CRD42022370942.

Prescription Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and Incidence of Depression Among Older Cancer Survivors With Osteoarthritis: A Machine Learning Analysis

ObjectiveS

This study examined prescription NSAIDs as one of the leading predictors of incident depression and assessed the direction of the association among older cancer survivors with osteoarthritis.

Methods

This study used a retrospective cohort (N = 14, 992) of older adults with incident cancer (breast, prostate, colorectal cancers, or non-Hodgkin's lymphoma) and osteoarthritis. We used the longitudinal data from the linked Surveillance, Epidemiology, and End Results -Medicare data for the study period from 2006 through 2016, with a 12-month baseline and 12-month follow-up period. Cumulative NSAIDs days was assessed during the baseline period and incident depression was assessed during the follow-up period. An eXtreme Gradient Boosting (XGBoost) model was built with 10-fold repeated stratified cross-validation and hyperparameter tuning using the training dataset. The final model selected from the training data demonstrated high performance (Accuracy: 0.82, Recall: 0.75, Precision: 0.75) when applied to the test data. SHapley Additive exPlanations (SHAP) was used to interpret the output from the XGBoost model.

Results

Over 50% of the study cohort had at least one prescption of NSAIDs. Nearly 13% of the cohort were diagnosed with incident depression, with the rates ranging between 7.4% for prostate cancer and 17.0% for colorectal cancer. The highest incident depression rate of 25% was observed at 90 and 120 cumulative NSAIDs days thresholds. Cumulative NSAIDs days was the sixth leading predictor of incident depression among older adults with OA and cancer. Age, education, care fragmentation, polypharmacy, and zip code level poverty were the top 5 predictors of incident depression.

Conclusion

Overall, 1 in 8 older adults with cancer and OA were diagnosed with incident depression. Cumulative NSAIDs days was the sixth leading predictor with an overall positive association with incident depression. However, the association was complex and varied by the cumulative NSAIDs days.

Practical Considerations for the Use of Cannabis in Cancer Pain Management—What a Medical Oncologist Should Know

Pain is a highly debilitating emotional and sensory experience that significantly affects quality of life (QoL). Numerous chronic conditions, including cancer, are associated with chronic pain. In the setting of malignancy, pain can be a consequence of the tumor itself or of life-saving interventions, including surgery, chemotherapy, and radiotherapy. Despite significant pharmacological advances and awareness campaigns, pain remains undertreated in one-third of patients. To date, opioids have been the mainstay of cancer pain management. The problematic side effects and unsatisfactory pain relief of opioids have revived patients’ and physicians’ interest in finding new solutions, including cannabis and cannabinoids. The medical use of cannabis has been prohibited for decades, and it remains in Schedule 1 of the Misuse of Drugs Regulations. Currently, the legal context for its usage has become more permissive. Various preclinical and observational studies have aimed to prove that cannabinoids could be effective in cancer pain management. However, their clinical utility must be further supported by high-quality clinical trials.

Non-opioid Analgesics and Emerging Therapies

Pain is a common and debilitating symptom of cancer. Cancer-related pain can occur at any point along the continuum from diagnosis to treatment to survivorship¹. A systematic review published in 2016 estimated the prevalence of cancer pain to be 55% in those undergoing antineoplastic treatment, 66.4% in advanced cancer, and 39.3% in the post-treatment population. Thirty-eight percent of cancer patients in this pooled analysis experienced moderate to severe pain².

Factors related to pain management adequacy in patients receiving palliative care: data from a tertiary hospital in Indonesia

BACKGROUND Adequate pain management must be applied to improve the quality of life, particularly in patients receiving palliative care. Thus, this study aimed to determine the factors related to pain management adequacy in patients receiving palliative care. METHODS This cross-sectional study included all patients sent for consultation to the palliative care team complaining of pain in Cipto Mangunkusumo Hospital, Jakarta, Indonesia from 2016 to 2018. All data such as gender, age, employment status, disease type, primary cancer location, pain intensity, analgesic drug treatment duration, and the presence of anxiety and depression were retrieved from medical records. Pain management adequacy was evaluated using the pain management index. Logistic regression included all variables with p<0.25 related to pain management adequacyin bivariate analysis. RESULTS Out of 175 patients with pain, 85.7% reported having adequate pain management. Pain was more adequately treated in patients with employment (p = 0.001), milder pain intensity (p<0.001), those using opioids (p<0.001), and those who did not experience anxiety (p = 0.05). Factors related to pain management adequacy were opioid use (OR = 3.23, 95% CI = 1.71–6.13) and milder pain (OR = 11.15, 95% CI = 3.89–31.99). CONCLUSIONS Most of the patients received adequate pain management which related to opioid use and milder pain.

Acupuncture for Cancer Related Pain: Protocol for a Pragmatic Randomised Wait-List Controlled Trial

BACKGROUND

Acupuncture has been proved effective for cancer related pain (CRP) in China, America and some other countries. However, there is relative lack of evidence to support the use of acupuncture for CRP in Australia.

OBJECTIVES

To assess the effectiveness and safety of acupuncture for management of CRP in a real-world setting and to understand cancer patients' experience of undergoing acupuncture for CRP.

METHODS

A pragmatic randomised controlled trial will be conducted in South Western Sydney Local Health District (SWSLHD) in NSW, Australia. Adults with cancer related pain (n = 106) will be randomised in a 1:1 ratio to receive the acupuncture intervention up front versus after a wait list period of 4 weeks. Pain level (by Numerical Rating Scale), analgesic use, auricular acupressure frequency and adverse events will be assessed at baseline, mid-treatment and post-treatment. Expectancy on trial outcome (by Credibility and Expectancy questionnaire) will be assessed at baseline. The perspective of the participants (by an interview) will be recorded after the last intervention.

EXPECTED OUTCOMES

We hypothesise that acupuncture will relieve cancer related pain at mid-treatment and post-treatment. We also hypothesise that few adverse events will be provoked by acupuncture.

TRIAL REGISTRATION

Australia New-Zealand Clinical Trial Registry (ACTRN12620000325909).

Analgesic Prescription Patterns and Pain Outcomes in Southeast Asia: Findings From the Analgesic Treatment of Cancer Pain in Southeast Asia Study

Purpose

To identify patterns of analgesic prescription and to explore patient-reported pain intensity, sleep disturbance, and quality of life among cancer patients with pain in Southeast Asia (SEA).

Methods

This cross-sectional observational study included 465 adult outpatients prescribed analgesics for cancer pain for 1 month or longer at 22 sites in Indonesia, Malaysia, Philippines, Singapore, Thailand, and Vietnam. Data on analgesic prescription and cancer characteristics were extracted from medical records. Pain intensity, sleep disturbance, and quality of life measures were recorded via questionnaires.

Results

Most patients (84.4%) had stage III or IV cancer. A total of 419 patients (90.7%) were prescribed opioids; of these, 42.2% received only weak opioids, whereas 57.8% received at least one strong opioid. The mean worst pain intensity during the past 24 hours was 4.76 (standard deviation [SD], 2.47) on a scale of 0 (no pain) to 10 (worst possible pain); the mean current pain intensity was 4.10 (SD, 2.61). More than half of patients (54.8%) reported sleep disturbance caused by pain in the past 7 days. The majority of patients reported problems with pain/discomfort (82.3%), usual activities (65.8%), mobility (58.2%), and anxiety/depression (56.3%). The median daily dose prescribed in oral morphine equivalents was 30 mg for both morphine and tramadol.

Conclusion

Despite unrelieved pain, sleep disturbance, and issues with quality of life, a notable proportion of patients were prescribed only weak opioids, and opioid doses prescribed were generally low. Efforts focused on encouragement of prescriptions with analgesic strength and/or doses proportional to the pain management needs of patients are vital to improve the status of cancer pain management in the region.

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.

A systematic review and meta-analysis of randomized controlled trials of palliative care for pain among Chinese adults with cancer

Background

Pain is one of the most common symptoms that has a severe impact on quality of life and is associated with numerous psychosocial issues in cancer patients. Palliative care, which is a recent development in China, mainly focuses on symptom control and provides psychosocial support in order to improve quality of life for terminally ill patients. This meta-analysis aimed to evaluate the effects of palliative care on cancer pain in China.

Methods

The four most comprehensive Chinese academic databases-CNKI, Wanfang, Vip and CBM-were searched from their inception until July 2019. Medline/PubMed, Web of Science, EBSCO and internet search (Google and Google Scholar) were also searched. Randomized controlled studies assessing the effects of palliative care on cancer pain were analyzed. The pooled random-effect estimates of standardized mean difference (SMD) and 95% confidence intervals (CI) were calculated. Subgroup analysis was conducted by moderating factors for heterogeneity.

Results

The present meta-analysis included 18 studies with a total of 1370 patients. The random-effect model showed a significant effect size of palliative care on cancer pain (SMD = 1.475, p < 0.001; 95% CI = 1.071–1.878). Age, pharmacological/non-pharmacological strategies and publication date could account for the heterogeneity through subgroup analysis to some extent.

Conclusions

Palliative care was largely effective for relieving pain among Chinese adults with cancer, indicating that an adequate system should be urgently established to provide palliative care for cancer patients in Chinese medical settings. However, given the extent of heterogeneity, our findings should be interpreted cautiously.

Electronic supplementary material

The online version of this article (10.1186/s12904-019-0456-z) contains supplementary material, which is available to authorized users.

Comparison of the antinociceptive profiles of morphine and oxycodone in two models of inflammatory and osteoarthritic pain in rat

Oxycodone and morphine are two opioid drugs commonly used for the treatment of moderate to severe pain. However, their use in the management of noncancer pain remains a controversial issue and, in this respect, the evidence on their effectiveness and safety, particularly in osteoarthritis, is being questioned. In order to analyse their analgesic profile, two different pain models in rats were used: the formalin-induced inflammatory pain and the monosodium iodoacetate (MIA)-induced knee osteoarthritic pain. Drugs were administered systemically (i.p.) and their antinociceptive effect and potency were assessed. In the formalin test, both morphine and oxycodone produced a dose-dependent antinociceptive effect, but oxycodone outdid morphine in terms of effectiveness and potency (nearly two times) in the early (acute nociceptive) as in the late phase (inflammatory). In the osteoarthritis model, both drugs reduced movement-evoked pain (knee-bend test), mechanical allodynia (von Frey test) and heat hyperalgesia (Plantar test). Pretreatment with naloxone and naloxone methiodide reduced morphine and oxycodone effects. Peripheral mu-opioid receptors play a crucial role in the antinociceptive effect of both drugs on movement-evoked pain and heat hyperalgesia, but not on tactile allodynia. The main finding of our study is that oxycodone has a better antinociceptive profile in the inflammatory and osteoarthritic pain, being more effective than morphine at 14 days post-MIA injection (phase with neuropathic pain); it overcame the morphine effect by improving the movement-induced pain, tactile allodynia and heat hyperalgesia. Therefore, oxycodone could be an interesting option to treat patients suffering from knee osteoarthritis when opioids are required.

Chronic Cancer Pain: Diagnostic Dilemma and Management Challenges

A 32-year-old female, diagnosed case of neuroendocrine tumor of pancreas, was admitted to the pain and palliative care unit with complaints of diffuse abdominal pain which was severe in intensity with score on numerical rating scale-9/10. Pain was not relieved even after taking tablet morphine immediate release 360 mg every 4 hourly, paracetamol 500 mg 6 hourly, and gabapentin 300 mg 8 hourly. She had undergone distal pancreatectomy with splenectomy and also received multiple lines of chemotherapy. After making a diagnosis of opioid-induced hyperalgesia, opioid rotation from morphine to fentanyl was done. This case report reflects various conditions where strong opioids fail to relieve cancer pain, and a multimodal approach is needed for its management.

Cancer pain management: recommendations from a Latin-American experts panel

Generating a consensus in the Latin-American region on cancer pain management is a current need. Thus a panel of Latin-American experts met in Madrid in March 2017 in order to review the published literature, discuss the best approach for cancer pain classification and evaluation and also make recommendations of pharmacological and nonpharmacological therapies for cancer pain management improvement in Latin-American countries. The result of that meeting is presented in this document. The experts participating were from Costa Rica, Mexico, Chile, Colombia, Peru, Brazil and Ecuador, and the project coordinator was from Spain.

Neuraxial drug delivery for the management of cancer pain: cost, updates, and society guidelines

PURPOSE OF REVIEW

The present study discusses the utilization of neuraxial drug delivery (NDD) for the management of cancer pain, based on recent trials, reviews, and guidelines with a focus on cost analysis.

RECENT FINDINGS

Almost all recent publications suggest that more stringent research is needed to improve evidence on NDD, particularly as conflicting reports exist regarding cost effectiveness of drug delivery systems. The combination of local anesthetics and opioids, with or without clonidine, continues to be reported as beneficial with the utilization of patient controlled systems providing an advantage over continuous ones. Interestingly, the use of opioids as an adjunct to local anesthetics may not enhance analgesia but the addition of dexamethasone is useful for incident cancer-related bone pain. Ziconitide remains supported as first-line therapy in districts where it is available - United States and Europe. Although new targeted drugs are being designed for cancer pain management, none have seen human clinical trials in the last year.

SUMMARY

The ability to demonstrate cost effectiveness of NDD is variable from region to region. Less expensive externalized systems may pose a viable alternative. With the exception of dexamethasone, no new drugs have been shown to provide any benefit to conventional medications.

Oral nonsteroidal anti-inflammatory drugs (NSAIDs) for cancer pain in adults

BACKGROUND

Pain is a common symptom with cancer, and 30% to 50% of all people with cancer will experience moderate to severe pain that can have a major negative impact on their quality of life. Non-opioid drugs are commonly used to treat cancer pain, and are recommended for this purpose in the World Health Organization (WHO) cancer pain treatment ladder, either alone or in combination with opioids.A previous Cochrane review that examined the evidence for nonsteroidal anti-inflammatory drugs (NSAIDs) or paracetamol, alone or combined with opioids, for cancer pain was withdrawn in 2015 because it was out of date; the date of the last search was 2005. This review, and another on paracetamol, updates the evidence.

OBJECTIVES

To assess the efficacy of oral NSAIDs for cancer pain in adults, and the adverse events reported during their use in clinical trials.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from inception to April 2017, together with reference lists of retrieved papers and reviews, and two online study registries.

SELECTION CRITERIA

We included randomised, double-blind, single-blind, or open-label studies of five days' duration or longer, comparing any oral NSAID alone with placebo or another NSAID, or a combination of NSAID plus opioid with the same dose of the opioid alone, for cancer pain of any pain intensity. The minimum study size was 25 participants per treatment arm at the initial randomisation.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. We did not carry out any pooled analyses. We assessed the quality of the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

Eleven studies satisfied inclusion criteria, lasting one week or longer; 949 participants with mostly moderate or severe pain were randomised initially, but fewer completed treatment or had results of treatment. Eight studies were double-blind, two single-blind, and one open-label. None had a placebo only control; eight compared different NSAIDs, three an NSAID with opioid or opioid combination, and one both. None compared an NSAID plus opioid with the same dose of opioid alone. Most studies were at high risk of bias for blinding, incomplete outcome data, or small size; none was unequivocally at low risk of bias.It was not possible to compare NSAIDs as a group with another treatment, or one NSAID with another NSAID. Results for all NSAIDs are reported as a randomised cohort. We judged results for all outcomes as very low-quality evidence.None of the studies reported our primary outcomes of participants with pain reduction of at least 50%, and at least 30%, from baseline; participants with Patient Global Impression of Change (PGIC) of much improved or very much improved (or equivalent wording). With NSAID, initially moderate or severe pain was reduced to no worse than mild pain after one or two weeks in four studies (415 participants in total), with a range of estimates between 26% and 51% in individual studies.Adverse event and withdrawal reporting was inconsistent. Two serious adverse events were reported with NSAIDs, and 22 deaths, but these were not clearly related to any pain treatment. Common adverse events were thirst/dry mouth (15%), loss of appetite (14%), somnolence (11%), and dyspepsia (11%). Withdrawals were common, mostly because of lack of efficacy (24%) or adverse events (5%).

AUTHORS' CONCLUSIONS

There is no high-quality evidence to support or refute the use of NSAIDs alone or in combination with opioids for the three steps of the three-step WHO cancer pain ladder. There is very low-quality evidence that some people with moderate or severe cancer pain can obtain substantial levels of benefit within one or two weeks.

Oral paracetamol (acetaminophen) for cancer pain

BACKGROUND

Pain is a common symptom with cancer, and 30% to 50% of all people with cancer will experience moderate to severe pain that can have a major negative impact on their quality of life. Non-opioid drugs are commonly used to treat mild to moderate cancer pain, and are recommended for this purpose in the WHO cancer pain treatment ladder, either alone or in combination with opioids.A previous Cochrane review that examined the evidence for nonsteroidal anti-inflammatory drugs (NSAIDs) or paracetamol, alone or combined with opioids, for cancer pain was withdrawn in 2015 because it was out of date; the date of the last search was 2005. This review, and another on NSAIDs, updates the evidence.

OBJECTIVES

To assess the efficacy of oral paracetamol (acetaminophen) for cancer pain in adults and children, and the adverse events reported during its use in clinical trials.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from inception to March 2017, together with reference lists of retrieved papers and reviews, and two online study registries.

SELECTION CRITERIA

We included randomised, double-blind, studies of five days' duration or longer, comparing paracetamol alone with placebo, or paracetamol in combination with an opioid compared with the same dose of the opioid alone, for cancer pain of any intensity. Single-blind and open studies were also eligible for inclusion. The minimum study size was 25 participants per treatment arm at the initial randomisation.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. We did not carry out any pooled analyses. We assessed the quality of the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

Three studies in adults satisfied the inclusion criteria, lasting up to one week; 122 participants were randomised initially, and 95 completed treatment. We found no studies in children. One study was parallel-group, and two had a cross-over design. All used paracetamol as an add-on to established treatment with strong opioids (median daily morphine equivalent doses of 60 mg, 70 mg, and 225 mg, with some participants taking several hundred mg of oral morphine equivalents daily). Other non-paracetamol medication included non-steroidal anti-inflammatory drugs (NSAIDs), tricyclic antidepressants, or neuroleptics. All studies were at high risk of bias for incomplete outcome data and small size; none was unequivocally at low risk of bias.None of the studies reported any of our primary outcomes: participants with pain reduction of at least 50%, and at least 30%, from baseline; participants with pain no worse than mild at the end of the treatment period; participants with Patient Global Impression of Change (PGIC) of much improved or very much improved (or equivalent wording). What pain reports there were indicated no difference between paracetamol and placebo when added to another treatment. There was no convincing evidence of paracetamol being different from placebo with regards to quality of life, use of rescue medication, or participant satisfaction or preference. Measures of harm (serious adverse events, other adverse events, and withdrawal due to lack of efficacy) were inconsistently reported and provided no clear evidence of difference.Our GRADE assessment of evidence quality was very low for all outcomes, because studies were at high risk of bias from several sources.

AUTHORS' CONCLUSIONS

There is no high-quality evidence to support or refute the use of paracetamol alone or in combination with opioids for the first two steps of the three-step WHO cancer pain ladder. It is not clear whether any additional analgesic benefit of paracetamol could be detected in the available studies, in view of the doses of opioids used.

Opioids for cancer pain - an overview of Cochrane reviews

BACKGROUND

Pain is a common symptom with cancer, and 30% to 50% of all people with cancer will experience moderate to severe pain that can have a major negative impact on their quality of life. Opioid (morphine-like) drugs are commonly used to treat moderate or severe cancer pain, and are recommended for this purpose in the World Health Organization (WHO) pain treatment ladder. The most commonly-used opioid drugs are buprenorphine, codeine, fentanyl, hydrocodone, hydromorphone, methadone, morphine, oxycodone, tramadol, and tapentadol.

OBJECTIVES

To provide an overview of the analgesic efficacy of opioids in cancer pain, and to report on adverse events associated with their use.

METHODS

We identified systematic reviews examining any opioid for cancer pain published to 4 May 2017 in the Cochrane Database of Systematic Reviews in the Cochrane Library. The primary outcomes were no or mild pain within 14 days of starting treatment, withdrawals due to adverse events, and serious adverse events.

MAIN RESULTS

We included nine reviews with 152 included studies and 13,524 participants, but because some studies appeared in more than one review the number of unique studies and participants was smaller than this. Most participants had moderate or severe pain associated with a range of different types of cancer. Studies in the reviews typically compared one type of opioid or formulation with either a different formulation of the same opioid, or a different opioid; few included a placebo control. Typically the reviews titrated dose to effect, a balance between pain relief and adverse events. Various routes of administration of opioids were considered in the reviews; oral with most opioids, but transdermal administration with fentanyl, and buprenorphine. No review included studies of subcutaneous opioid administration. Pain outcomes reported were varied and inconsistent. The average size of included studies varied considerably between reviews: studies of older opioids, such as codeine, morphine, and methadone, had low average study sizes while those involving newer drugs tended to have larger study sizes.Six reviews reported a GRADE assessment (buprenorphine, codeine, hydromorphone, methadone, oxycodone, and tramadol), but not necessarily for all comparisons or outcomes. No comparative analyses were possible because there was no consistent placebo or active control. Cohort outcomes for opioids are therefore reported, as absolute numbers or percentages, or both.Reviews on buprenorphine, codeine with or without paracetamol, hydromorphone, methadone, tramadol with or without paracetamol, tapentadol, and oxycodone did not have information about the primary outcome of mild or no pain at 14 days, although that on oxycodone indicated that average pain scores were within that range. Two reviews, on oral morphine and transdermal fentanyl, reported that 96% of 850 participants achieved that goal.Adverse event withdrawal was reported by five reviews, at rates of between 6% and 19%. Participants with at least one adverse event were reported by three reviews, at rates of between 11% and 77%.Our GRADE assessment of evidence quality was very low for all outcomes, because many studies in the reviews were at high risk of bias from several sources, including small study size.

AUTHORS' CONCLUSIONS

The amount and quality of evidence around the use of opioids for treating cancer pain is disappointingly low, although the evidence we have indicates that around 19 out of 20 people with moderate or severe pain who are given opioids and can tolerate them should have that pain reduced to mild or no pain within 14 days. This accords with the clinical experience in treating many people with cancer pain, but overstates to some extent the effectiveness found for the WHO pain ladder. Most people will experience adverse events, and help may be needed to manage the more common undesirable adverse effects such as constipation and nausea. Perhaps between 1 in 10 and 2 in 10 people treated with opioids will find these adverse events intolerable, leading to a change in treatment.

Tramadol with or without paracetamol (acetaminophen) for cancer pain

BACKGROUND

Tramadol is an opioid analgesic licensed for use in moderate to severe pain. It is considered as a low risk for abuse, so control regulations are not as stringent as for 'strong' opioids such as morphine. It has a potential role as a step 2 option of the World Health Organization (WHO) analgesic ladder.

OBJECTIVES

To assess the benefits and adverse effects of tramadol with or without paracetamol (acetaminophen) for cancer-related pain.

SEARCH METHODS

We searched the following databases using a wide range of search terms: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and LILACS. We also searched three clinical trials registry databases. The date of the last search was 2 November 2016.

SELECTION CRITERIA

We selected studies that were randomised, with placebo or active controls, or both, and included a minimum of 10 participants per treatment arm. We were interested particularly in blinded studies, but also included open studies.We excluded non-randomised studies, studies of experimental pain, case reports, and clinical observations.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data using a standard form and checked for agreement before entry into Review Manager 5. We included information about the number of participants treated and demographic details, type of cancer, drug and dosing regimen, study design (placebo or active control) and methods, study duration and follow-up, analgesic outcome measures and results, withdrawals, and adverse events. We collated multiple reports of the same study, so that each study, rather than each report, was the unit of interest in the review. We assessed the evidence using GRADE and created a 'Summary of findings' table.The main outcomes of interest for benefit were pain reduction of 30% or greater and 50% or greater from baseline, participants with pain no worse than mild, and participants feeling much improved or very much improved.

MAIN RESULTS

We included 10 studies (12 reports) with 958 adult participants. All the studies enrolled participants with chronic malignant tumour-related pain who were experiencing pain intensities described as moderate to severe, with most experiencing at least 4/10 with current treatment. The mean ages were 59 to 70 years, with participants aged between 24 and 87 years. Study length ranged from one day to six months. Five studies used a cross-over design. Tramadol doses ranged from 50 mg as single dose to 600 mg per day; doses of 300 mg per day to 400 mg per day were most common.Nine studies were at high risk of bias for one to four criteria (only one high risk of bias for size). We judged all the results to be very low quality evidence because of widespread lack of blinding of outcome assessment, inadequately described sequence generation, allocation concealment, and small numbers of participants and events. Important outcomes were poorly reported. There were eight different active comparators and one comparison with placebo. There was little information available for any comparison and no firm conclusions could be drawn for any outcome.Single comparisons of oral tramadol with codeine plus paracetamol, of dihydrocodeine, and of rectal versus oral tramadol provided no data for key outcomes. One study used tramadol combined with paracetamol; four participants received this intervention. One study compared tramadol with flupirtine - a drug that is no longer available. One study compared tramadol with placebo and a combination of cobrotoxin, tramadol, and ibuprofen, but the dosing schedule poorly explained.Two studies (191 participants) compared tramadol with buprenorphine. One study (131 participants) reported a similar proportion of no or mild pain at 14 days.Three studies (300 participants) compared tramadol with morphine. Only one study, combining tramadol, tramadol plus paracetamol, and paracetamol plus codeine as a single weak-opioid group reported results. Weak opioid produced reduction in pain of at least 30% from baseline in 55/117 (47%) participants, compared with 91/110 (82%) participants with morphine. Weak opioid produced reduction in pain of at least 50% in 49/117 (42%) participants, compared with 83/110 (75%) participants with morphine.There was no useful information for any other outcome of benefit or harm.

AUTHORS' CONCLUSIONS

There is limited, very low quality, evidence from randomised controlled trials that tramadol produced pain relief in some adults with pain due to cancer and no evidence at all for children. There is very low quality evidence that it is not as effective as morphine. This review does not provide a reliable indication of the likely effect. The likelihood that the effect will be substantially different is very high. The place of tramadol in managing cancer pain and its role as step 2 of the WHO analgesic ladder is unclear.

Tetrodotoxin for Moderate to Severe Cancer-Related Pain: A Multicentre, Randomized, Double-Blind, Placebo-Controlled, Parallel-Design Trial

Objective

This study evaluated subcutaneous injections of tetrodotoxin (TTX) for the treatment of moderate to severe, inadequately controlled cancer-related pain.

Methods

Eligible patients were randomized to receive TTX (30 μg) or placebo subcutaneously twice daily for four consecutive days. Efficacy was assessed using pain and composite endpoints (including pain and quality of life measures), and safety was evaluated using standard measures.

Results

165 patients were enrolled at 19 sites in Canada, Australia, and New Zealand, with 149 patients in the primary analysis “intent-to-treat” population. The primary analysis supports a clinical benefit of TTX over placebo based on the pain endpoint alone with a clinically significant estimated effect size of 16.2% (p = 0.0460). The p value was nominally statistically significant after prespecified (Bonferroni Holm) adjustment for the two primary endpoints but not at the prespecified two-sided 5% level. The mean duration of analgesic response was 56.7 days (TTX) and 9.9 days (placebo). Most common adverse events were nausea, dizziness, and oral numbness or tingling and were generally mild to moderate and transient.

Conclusions

Although underpowered, this study demonstrates a clinically important analgesic signal. TTX may provide clinically meaningful analgesia for patients who have persistent moderate to severe cancer pain despite best analgesic care. This clinical study is registered with ClinicalTrials.gov (NCT00725114).

Opioids Resistance in Chronic Pain Management

Chronic pain management represents a serious healthcare problem worldwide. Chronic pain affects approximately 20% of the adult European population and is more frequent in women and older people. Unfortunately, its management in the community remains generally unsatisfactory and rarely under the control of currently available analgesics. Opioids have been used as analgesics for a long history and are among the most used drugs; however, while there is no debate over their short term use for pain management, limited evidence supports their efficacy of long-term treatment for chronic non-cancer pain. Therapy with opioids is hampered by inter-individual variability and serious side effects and some opioids often result ineffective in the treatment of chronic pain and their use is controversial. Accordingly, for a better control of chronic pain a deeper knowledge of the molecular mechanisms underlying resistance to opiates is mandatory.

Effects of miR-338 on morphine tolerance by targeting CXCR4 in a rat model of bone cancer pain

The present study aimed to investigate the effects of miR-338 on morphine tolerance through the targeting of CXC chemokine receptor-4 (CXCR4) in a rat model of bone cancer pain (BCP). Sprague–Dawley (SD) rats were obtained and divided into model saline (n=10), model morphine (n=50), normal saline (n=10) and normal morphine (healthy rats, n=10) groups. After BCP rat model establishment, the remaining SD rats (n=40) in the model saline group were assigned into pLV-THM-miR-338, pLV-THM-anti-miR-338, CXCR4 shRNA, blank and PBS groups. Luciferase reporter gene assay was used for luciferase activity. Quantitative real-time PCR (qRT-PCR) and Western blotting were performed to detect the miR-338 and CXCR4 mRNA and protein expression. The model saline group showed increased mRNA and protein expressions of CXCR4 but decreased miR-338 compared with the model saline group, and the model morphine group had increased mRNA and protein expressions of CXCR4 but decreased miR-338 compared with the model saline group. The mRNA and protein expressions of miR-338 in the pLV-THM-miR-338 group increased remarkably while those of the pLV-THM-anti-miR-338 group decreased significantly compared with the CXCR4 shRNA, blank and PBS groups. The pLV-THM-miR-338, pLV-THM-anti-miR-338, CXCR4 shRNA and CXCR4 mRNA groups all had lower mRNA and protein expressions of CXCR4 than those in the blank and PBS groups. miR-338 exerts significant influence in the inhibition of morphine tolerance by suppressing CXCR4 in BCP.

Encountering a Neglected Area of a Healthcare System: A Decade of Improvement in Cancer Pain Clinical Practice in Iran

Background

With the increase in the prevalence of cancer, cancer-related issues also deserve more attention especially in developing countries where there is already limited access to high-quality healthcare. Cancer-related pain, the most common and the most annoying one, is not only a symptom but also an important subspecialty and its management is still challenging.

Objectives

To assess the level of pain and cancer pain knowledge in Iran in comparison with the whole world.

Materials and Method

A search of the literature including papers published in PubMed before March 2016 was carried out.

Results

There have been an increasing number of publications on pain since 1842 and a growing number of publications on cancer pain since 1929. There has also been remarkable growth in our understanding of cancer pain, particularly since 2010. More than one-third of studies on pain and cancer-related pain were published after 2010.

Conclusion

There is a need to be more inventive with the management of cancer-related issues, especially pain in developing countries, to maximize the quality and quantity of healthcare delivery to cancer-stricken patients. It seems that non-governmental organizations like MAHAK can play a significant role in this goal.

Opioid-induced redistribution of 6TM and 7TM μ opioid receptors: A hypothesized mechanistic facilitator model of opioid-induced hyperalgesia

Opioids are still the most popular form of pain treatment, but many unavoidable side effects make opioids a big challenge in effective pain management. Opioid-induced hyperalgesia (OIH), a paradoxical phenomenon, portrays an increased sensitivity to harmful stimuli caused by opioid exposure. Changes in the neural modulation are considered a major contributor to the development of OIH. Activation of opioid receptors (ORs) and corresponding downstream molecules are the vital composition of functional performance of opioids. Increasing interests were proposed of the interaction between ORs and other neural transmitter systems such as glutamatergic, GABAergic and adrenergic ones to the genesis of OIH. G protein coupled μ-opioid receptor (MOR) was studied comprehensively on its role in the development of OIH. In addition to the relationship between MOR and other neurotransmitter receptors, a new intracellular MOR that has six transmembrane (6TM) domains was identified, and found to perform a pro-nociceptive task in contrast to the counterpart 7TM isoform. A mechanistic model of OIH in which both 6TM and 7TM MORs undergoing membrane redistribution upon opioid exposure is proposed which eventually facilitates the neurons more sensitive to nociceptive stimulation than that of the preceding opioid exposure.