Is regular systemic opioid analgesia associated with shorter survival in adult patients with cancer? A systematic literature review

Effects of Opioids in Cancer Pain: An Interplay Among Genetic Factors, Immune Response, and Clinical Outcomes-A Scoping Review

Background/Objectives: Managing cancer-related pain presents complex challenges involving the interplay between analgesic efficacy, immune system responses, and patient outcomes. Methods: Following the Scale for the Assessment of Narrative Review Articles (SANRA) criteria, we conducted a comprehensive literature search in Medline, Scopus, and Web of Science databases. The review synthesized evidence regarding opioid pain management modalities, genetic variations affecting pain perception, and associated drug metabolism. Results: The literature reveals significant associations between opioid administration and immune function, with potential implications for cancer progression and survival. Genetic polymorphisms in key genes influence individual responses to pain opioid metabolism and, finally, pain management strategies. The immunosuppressive effects of opioids emerge as a critical consideration in cancer pain management, potentially influencing disease progression and treatment outcomes. Conclusions: Genetic variants influence analgesic efficacy, while the interaction between opioid-induced immunosuppression and genetic factors impacts both pain control and survival outcomes. This emphasizes the need for personalized treatment approaches considering individual genetic profiles and immune function.

Effects of propofol, benzodiazepines, and opioids on survival in cancer patients: a retrospective cohort study based on MIMIC-III

Sedative and analgesic drugs are commonly used in the diagnosis and treatment of cancer patients. Analyzing the impact of these drugs on the prognosis of cancer patients can help improve patient outcomes. This study aimed to analyze the use of propofol, benzodiazepines, and opioids on the survival of cancer patients in the intensive care unit (ICU) based on the Medical Information Mart for Intensive Care III (MIMIC-III) database. A total of 2,567 cancer patients from the MIMIC-III database between 2001 and 2012 were included in this retrospective cohort study. Logistic regression analyses were utilized to assess the relationship between propofol, benzodiazepine, and opioid and survival in cancer patients. The follow-up was 1 year from the patient's first admission to the ICU. Outcomes were ICU mortality, 28-day mortality, and 1-year mortality. Stratified analyses were based on patients' metastatic status. The use of propofol [odds ratio (OR) = 0.66; 95% confidence interval (CI), 0.53-0.80] and opioids (OR = 0.65; 95%CI, 0.54-0.79) were associated with a decreased risk of 1-year mortality. Both benzodiazepines and opioids use were related to an increased risk of ICU mortality and 28-day mortality (all P < 0.05), whereas propofol use was associated with a decreased risk of 28-day mortality (OR = 0.59; 95%CI, 0.45-0.78). Compared with the use of benzodiazepines combined with opioids, patients who used propofol and opioids were related to a decreased risk of 1-year mortality (OR = 0.74; 95%CI, 0.55-0.98). Similar results were found in patients with metastasis and metastasis-free. Cancer patients who used propofol may experience a lower risk of mortality than benzodiazepine use.

Morphine-induced osteolysis and hypersensitivity is mediated through toll-like receptor-4 in a murine model of metastatic breast cancer

ABSTRACT

The propensity for breast cancer to metastasize to bone is coupled to the most common complaint among breast cancer patients: bone pain. Classically, this type of pain is treated using escalating doses of opioids, which lack long-term efficacy due to analgesic tolerance, opioid-induced hypersensitivity, and have recently been linked to enhanced bone loss. To date, the molecular mechanisms underlying these adverse effects have not been fully explored. Using an immunocompetent murine model of metastatic breast cancer, we demonstrated that sustained morphine infusion induced a significant increase in osteolysis and hypersensitivity within the ipsilateral femur through the activation of toll-like receptor-4 (TLR4). Pharmacological blockade with TAK242 (resatorvid) as well as the use of a TLR4 genetic knockout ameliorated the chronic morphine-induced osteolysis and hypersensitivity. Genetic MOR knockout did not mitigate chronic morphine hypersensitivity or bone loss. In vitro studies using RAW264.7 murine macrophages precursor cells demonstrated morphine-enhanced osteoclastogenesis that was inhibited by the TLR4 antagonist. Together, these data indicate that morphine induces osteolysis and hypersensitivity that are mediated, in part, through a TLR4 receptor mechanism.

Effects of Opioids on Immune and Endocrine Function in Patients with Cancer Pain

OPINION STATEMENT

Opioids are an important treatment in managing cancer pain. Uncontrolled pain can be detrimental to function and quality of life. Common adverse effects of opioids such as sedation, constipation and nausea are well recognised, but opioid effects on the endocrine and immune systems are less apparent. The evidence for the immunomodulatory effects of opioids suggest that some opioids might be immunosuppressive and that their use might be associated with reduced survival and increased rates of infection in patients with cancer. However, the quality of this evidence is limited. Opioid-induced endocrinopathies, in particular opioid-induced hypogonadism, may also impact cancer survival and impair quality of life. But again, evidence in patients with cancer is limited, especially with regard to their management. There are some data that different opioids influence immune and endocrine function with varying outcomes. For example, some opioids, such as tramadol and buprenorphine, demonstrate immune-sparing qualities when compared to others. However, most of this data is preclinical and without adequate clinical correlation; thus, no opioid can currently be recommended over another in this context. Higher opioid doses might have more effect on immune and endocrine function. Ultimately, it is prudent to use the lowest effective dose to control the cancer pain. Clinical presentations of opioid-induced endocrinopathies should be considered in patients with cancer and assessed for, particularly in long-term opioid users. Hormone replacement therapies may be considered where appropriate with support from endocrinology specialists.

Use of Opioids for Adults With Pain From Cancer or Cancer Treatment: ASCO Guideline

PURPOSE

To provide guidance on the use of opioids to manage pain from cancer or cancer treatment in adults.

METHODS

A systematic review of the literature identified systematic reviews and randomized controlled trials of the efficacy and safety of opioid analgesics in people with cancer, approaches to opioid initiation and titration, and the prevention and management of opioid adverse events. PubMed and the Cochrane Library were searched from January 1, 2010, to February 17, 2022. American Society of Clinical Oncology convened an Expert Panel to review the evidence and formulate recommendations.

RESULTS

The evidence base consisted of 31 systematic reviews and 16 randomized controlled trials. Opioids have primarily been evaluated in patients with moderate-to-severe cancer pain, and they effectively reduce pain in this population, with well-characterized adverse effects. Evidence was limited for several of the questions of interest, and the Expert Panel relied on consensus for these recommendations or noted that no recommendation could be made at this time.

RECOMMENDATIONS

Opioids should be offered to patients with moderate-to-severe pain related to cancer or active cancer treatment unless contraindicated. Opioids should be initiated PRN (as needed) at the lowest possible dose to achieve acceptable analgesia and patient goals, with early assessment and frequent titration. For patients with a substance use disorder, clinicians should collaborate with a palliative care, pain, and/or substance use disorder specialist to determine the optimal approach to pain management. Opioid adverse effects should be monitored, and strategies are provided for prevention and management.Additional information is available at www.asco.org/supportive-care-guidelines.

Survival Outcomes Associated With the Size of Opioid Prescriptions in the Management of Chronic Pain Related to Advanced Nasopharyngeal Carcinoma

OBJECTIVE

Patients with advanced nasopharyngeal carcinoma (ANC) often experience chronic pain. Opioids are generally recommended to treat tumor-related pain, but increased opioid use may lead to detrimental aftereffects, particularly with respect to tumor progression, resulting in reduced quality of life and increased risk of death. Our objective was to investigate whether the high size of opioid prescriptions is associated with poor overall survival (OS) in patients with ANC.

METHODS

A consecutive cohort of patients with newly diagnosed ANC who underwent high or low opioid prescription size treatment during 2012-2019 was retrospectively identified from our medical institutions. Survival was estimated with the Kaplan-Meier method with a log-rank test. Multivariate binary logistic regression was used to assess the association between opioid use and OS, adjusting for age, sex, body mass index (BMI), Eastern Collaborative Oncology Group performance status (ECOG PS), and ANC histology. The criterion to distinguish between the high opioid prescription size group [HD] and the low opioid prescription size group [LD] was 5 mg of oral morphine equivalents (OME) per 24 hours.

RESULTS

The cohort consisted of 244 consecutive patients (HD: n = 120, median age = 66 years [range, 40-81 years]; LD: n = 124, median age = 65 years [40-82 years]. Patients who underwent treatment with a high opioid prescription size had a worse median OS than those who underwent treatment with a low opioid prescription size (5.1 vs 6.6 months), and the high opioid prescription size was associated with a remarkable 48% higher risk of death than the low opioid prescription size (HR 1.48, 95% CI 1.11-1.98; P = .005). The cumulative dose of opioids greater than or equal to 500 mg of OME was associated with a higher risk of death, adjusted for age, sex, BMI, ECOG PS, and ANC histology.

CONCLUSIONS

In patients with newly diagnosed ANC experiencing palliative care, a high opioid prescription size may be associated with shorter OS than a low opioid prescription size.

Effect of Opioids on Survival in Patients with Cancer

Opioids are commonly used for pain management in patients with cancer. They have a range of unwanted effects, including some that potentially influence cancer growth. This article reviews the data assessing the effects of opioids on survival in patients with cancer. Many studies assessing this show an association between opioids and decreased survival. This effect is present even at very low doses of opioids. These studies do not assess causality, so it is not known if it is a direct effect of opioids on survival. As the control groups are not matched to the opioid group it might be that opioids are being used to control pain and patients receiving opioids have more aggressive cancers and it is the underlying cancer which is causing the decreased survival. Furthermore, although some studies allude to different opioids having different effects on survival, often all opioids are pooled in analysis. Future work needs to try to ascertain causality and differentiate between different opioids, pain, and cancer-mediated effects on survival in specific cancer types. Until then, opioids should continue to be used in patients with cancer as part of measures to optimise comfort and quality of life.

Managing symptoms at the end of life: a guide for non-palliative care nurses

Nurses, regardless of their area of practice, may have to care for a person in their last days and hours of life. However, many nurses outside of specialist palliative and end of life care settings do not feel adequately prepared for this. Nurses can usually obtain advice from specialists working in local hospices or palliative care centres, but they may still find it challenging to act on that advice if it is not underpinned by their own knowledge base. This article provides a guide to assist non-palliative care nurses in recognising dying and managing common symptoms at the end of life.

The other side of the coin: Positive view on the role of opioids in cancer

Opioids have been used for medicinal purposes as an analgesic and recreational purposes as a euphorigenic throughout human history. Cancer patients are often treated with different doses of opioids concurrently with anti-cancer drugs for pain relief without exhibiting excessive adverse effects. The intersection of the biology of pain, opioid therapy, and disease progression represents the crux of the matters and is of potentially great importance in cancer care. For more than 20 years, multiple investigations have focused on the stimulatory effects of opioids on cancer cell growth, while in-depth studies on the inhibitory effects on cancer cell growth development have usually been neglected. This paper reviews the evidence regarding opioid therapies and their anti-cancer effects on various malignancies. Likewise, we have a glimpse into the molecular mechanisms necessary for pinpointing their positive or negative impacts on malignancies to raise awareness and stimulate more excellent dialogue regarding their carcinogenic/anticarcinogenic roles.

Opioid Prescription Is Associated With Increased Survival in Older Adult Patients With Pancreatic Cancer in the United States: A Propensity Score Analysis

PURPOSE

Few studies have assessed the interaction between pain treatment and mortality in pancreatic cancer. The aim of this study was to investigate the association between receipt of opioid prescriptions and survival in adults with pancreatic cancer.

METHODS

The SEER-Medicare linked database was used to identify patients diagnosed with late-stage pancreatic cancer between 2007 and 2015. Kaplan-Meier models were used to assess the association between opioid prescriptions in the year after cancer diagnosis and survival. Cox proportional hazard models were used to determine the association between opioid receipt and survival, adjusting for propensity score and other relevant confounders including cancer-directed therapies and palliative care referral.

RESULTS

A total of 5,770 older adults with pancreatic cancer were identified; 1,678 (29.1%) were prescribed opioids for at least 60 days. Median survival was increased in those with opioid prescriptions (6.0 months) compared with those without (4.0 months, P < .0001). After adjustment for confounders, opioid prescriptions were still associated with improved survival (hazard ratio 0.80; 95% CI, 0.75 to 0.86). On multivariable analysis, opioid prescriptions were associated with older age, female sex, residing in nonmetro areas, and treatment with celiac plexus neurolysis, chemotherapy, and radiation.

CONCLUSION

Receipt of opioid prescriptions is associated with longer survival in patients with pancreatic cancer. This may be due to the impact of cancer-related pain, although further studies are needed to better understand the interaction between pain management, cancer-directed therapies, and systemic factors, such as palliative care, availability of opioids, and clinical practice culture.

Less Well-Known Consequences of the Long-Term Use of Opioid Analgesics: A Comprehensive Literature Review

BACKGROUND

The adverse effects of short-term opioid analgesics are well known and acknowledged; however, the spectrum of the sequelae of long-term use seems less clear. Some effects may remain undetected but still have the potential to cause harm and reduce patients' quality of life.

OBJECTIVE

To review the literature on the adverse effects of long-term opioid therapy.

METHODS

We performed a quasi-systematic search, analyzing articles published in the MEDLINE database between January 2000 and March 2021 that identified adverse effects of opioids used for chronic pain treatment.

RESULTS

Growing evidence indicates that there are multiple serious adverse effects of opioid treatment. Long-term opioid use may have significant effects on the endocrine, immune, cardiovascular, respiratory, gastrointestinal, and neural systems. Studies show that long-term opioid treatment increases the risk of fractures, infections, cardiovascular complications, sleep-disordered breathing, bowel dysfunction, overdose, and mortality. Opioids may potentially affect cancer development. Most consequences of the long-term use of opioids have been identified in studies of patients with non-malignant pain.

CONCLUSION

Studies indicate that long-term use of opioids increases the risk of drug-related events in a significant number of patients. Clinicians should be aware of these complications associated with prescribing opioids, discuss them with patients, prevent complications, if possible, and diagnose them early and manage adequately. More human studies are needed to assess the risk, including trials with individual opioids, because they have different adverse effect profiles.

Pain self-management interventions for community-based patients with advanced cancer: a research programme including the IMPACCT RCT

Background

Each year in England and Wales, 150,000 people die from cancer, of whom 110,000 will suffer from cancer pain. Research highlights that cancer pain remains common, severe and undertreated, and may lead to hospital admissions.

Objective

To develop and evaluate pain self-management interventions for community-based patients with advanced cancer.

Design

A programme of mixed-methods intervention development work leading to a pragmatic multicentre randomised controlled trial of a multicomponent intervention for pain management compared with usual care, including an assessment of cost-effectiveness.

Participants

Patients, including those with metastatic solid cancer (histological, cytological or radiological evidence) and/or those receiving anti-cancer therapy with palliative intent, and health professionals involved in the delivery of community-based palliative care.

Setting

For the randomised controlled trial, patients were recruited from oncology outpatient clinics and were randomly allocated to intervention or control and followed up at home.

Interventions

The Supported Self-Management intervention comprised an educational component called Tackling Cancer Pain, and an eHealth component for routine pain assessment and monitoring called PainCheck.

Main outcome measures

The primary outcome was pain severity (measured using the Brief Pain Inventory). The secondary outcomes included pain interference (measured using the Brief Pain Inventory), participants’ pain knowledge and experience, and cost-effectiveness. We estimated costs and health-related quality-of-life outcomes using decision modelling and a separate within-trial economic analysis. We calculated incremental cost-effectiveness ratios per quality-adjusted life-year for the trial period.

Results

Work package 1 – We found barriers to and variation in the co-ordination of advanced cancer care by oncology and primary care professionals. We identified that the median time between referral to palliative care services and death for 42,758 patients in the UK was 48 days. We identified key components for self-management and developed and tested our Tackling Cancer Pain resource for acceptability. Work package 2 – Patients with advanced cancer and their health professionals recognised the benefits of an electronic system to monitor pain, but had reservations about how such a system might work in practice. We developed and tested a prototype PainCheck system. Work package 3 – We found that strong opioids were prescribed for 48% of patients in the last year of life at a median of 9 weeks before death. We delivered Medicines Use Reviews to patients, in which many medicines-related problems were identified. Work package 4 – A total of 161 oncology outpatients were randomised in our clinical trial, receiving either supported self-management (n = 80) or usual care (n = 81); their median survival from randomisation was 53 weeks. Primary and sensitivity analyses found no significant treatment differences for the primary outcome or for other secondary outcomes of pain severity or health-related quality of life. The literature-based decision modelling indicated that information and feedback interventions similar to the supported self-management intervention could be cost-effective. This model was not used to extrapolate the outcomes of the trial over a longer time horizon because the statistical analysis of the trial data found no difference between the trial arms in terms of the primary outcome measure (pain severity). The within-trial economic evaluation base-case analysis found that supported self-management reduced costs by £587 and yielded marginally higher quality-adjusted life-years (0.0018) than usual care. However, the difference in quality-adjusted life-years between the two trial arms was negligible and this was not in line with the decision model that had been developed. Our process evaluation found low fidelity of the interventions delivered by clinical professionals.

Limitations

In the randomised controlled trial, the low fidelity of the interventions and the challenge of the study design, which forced the usual-care arm to have earlier access to palliative care services, might explain the lack of observed benefit. Overall, 71% of participants returned outcome data at 6 or 12 weeks and so we used administrative data to estimate costs. Our decision model did not include the negative trial results from our randomised controlled trial and, therefore, may overestimate the likelihood of cost-effectiveness.

Conclusions

Our programme of research has revealed new insights into how patients with advanced cancer manage their pain and the challenges faced by health professionals in identifying those who need more help. Our clinical trial failed to show an added benefit of our interventions to enhance existing community palliative care support, although both the decision model and the economic evaluation of the trial indicated that supported self-management could result in lower health-care costs.

Future work

There is a need for further research to (1) understand and facilitate triggers that prompt earlier integration of palliative care and pain management within oncology services; (2) determine the optimal timing of technologies for self-management; and (3) examine prescriber and patient behaviour to achieve the earlier initiation and use of strong opioid treatment.

Trial registration

Current Controlled Trials ISRCTN18281271.

Funding

This project was funded by the National Institute for Health Research Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 15. See the NIHR Journals Library website for further project information.

Lung Cancer Cell-Derived Exosomal let-7d-5p Down-Regulates OPRM1 to Promote Cancer-Induced Bone Pain

Cancer-induced bone pain (CIBP) is the pain caused by metastasis of malignant tumors to the bone, accounting for more than half of all chronic cancer pain, which seriously affects the quality of life among tumor patients. Up to 40% of patients with advanced lung cancer suffer from CIBP. MicroRNA (miRNA) transfers between cells through exosomes, mediates cell-to-cell communication, and performs various biological functions. Studies have shown that miRNAs secreted by cancer can modify the tumor microenvironment, but whether exosome-mediated miRNA transfer plays a role in CIBP is still unknown. In this study, the expression levels of 15 miRNAs in exosomes derived A549 cells and 18 miRNAs in exosomes derived NCI-H1299 cells were significantly up-regulated, and qRT-PCR further confirmed that the level of let-7d-5p was increased most considerably. In vitro, exosomal let-7d-5p (EXO let-7d-5p) can be taken up by dorsal root ganglion (DRG) neurons and inhibit the protein level of the target gene opioid receptor mu 1 (OPRM1). EXO let-7d-5p was further confirmed to be involved in the generation and maintenance of CIBP in vivo. Our findings clarify the molecular mechanism of CIBP caused by the inhibition of OPRM1 by EXO let-7d-5p, providing new clues and intervention targets for the prevention and treatment of CIBP.

Regular dosing compared with as-needed dosing of opioids for management of chronic cancer pain: systematic review and meta-analysis

Opioids are the recommended form of analgesia for patients with persistent cancer pain, and regular dosing "by the clock" is advocated in many international guidelines on cancer pain management. The development of sustained-release opioid preparations has made regular dosing easier for patients. However, patients report that the intensity and impact of their cancer pain varies considerably day to day, and many try to find a trade-off between acceptable pain control and impact of cognitive (and other) adverse effects on daily activities. In acute care settings, (eg, postoperative) as-needed dosing and other opioid-sparing approaches have resulted in better patient outcomes compared with regular dosing. The aim of this study was to determine whether regular dosing of opioids was superior to as-needed dosing for persistent cancer pain. We systematically searched for randomised controlled trials that directly compared pain outcomes from regular dosing of opioids with as-needed dosing in adult cancer patients. We identified 4347 records, 25 randomised controlled trials meet the inclusion criteria, 9 were included in the review, and 7 of these included in meta-analysis. We found no clear evidence demonstrating superiority of regular dosing of opioids compared with as-needed dosing in persistent cancer pain, and regular dosing was associated with significantly higher total opioid doses. There was, however, a paucity of trials directly answering this question, and low-quality evidence limits the conclusions that can be drawn. It is clear that further high-quality clinical trials are needed to answer this question and to guide clinical practice.

Chronic cancer and non-cancer pain and opioid-induced hyperalgesia share common mechanisms: neuroinflammation and central sensitization

Neuroinflammation, a peculiar form of inflammation that occurs in response to noxious stimuli in peripheral and central nervous system (CNS), consists in altered vascular permeability followed by leukocyte recruitment and activation in the inflamed tissue, release of inflammatory mediators including cytokines and chemokines, and finally in the activation of microglia and astrocytes in the spinal cord and CNS. This phenomenon mediates and even worsen the inflammatory pain in many painful states and is responsible for central sensitization leading to pain chronicity. We describe the major neuroinflammatory mechanisms shared by cancer and non-cancer pain. Particular attention is given to two different chronic inflammatory painful diseases such as the complex regional pain syndrome and the rheumatoid arthritis as prototypes of neuroinflammatory diseases (gliopathies). In addition, we describe the complexity of tumor microenvironment, their main cellular components (tumor cells, tumor infiltrating leukocytes and sensory neurons) and their reciprocal interactions that characterize different forms and intensity of cancer pain. We also hypothesize that one type of cancer pain, the breakthrough pain, can be attributable to receptor-mediated interaction of opioids with tumor cells and intratumoral leukocytes. Surprisingly, long-term opioid treatment shares the same neuroinflammatory potential responsible for the chronicity of both cancer and non-cancer pain; thus, resulting in paradoxical worsening rather than relieving pain. This paradox has upset the world of pain therapy, with neuroinflammation now being a main target of emerging therapies.

Current Perspectives on Spinal Cord Stimulation for the Treatment of Cancer Pain

Cancer and cancer treatment-related chronic pain affect a significant number of patients. The etiology of this pain is diverse and may include nociceptive and/or neuropathic characteristics. Treatment is often multifactorial and may require advanced interventional techniques, such as spinal cord stimulation (SCS). This narrative review provides a thorough overview of cancer-related pain mechanisms and the use of SCS for cancer-related pain. Additionally, a review of the precautions that should be considered when caring for this patient population is provided with recommendations for safe care when utilizing these techniques.

Oxygen use and survival in patients with advanced cancer and low oxygen saturation in home care: a preliminary retrospective cohort study

Background

The role of oxygen therapy in end-of-life care for patients with advanced cancer is incompletely understood. We aimed to evaluate the association between oxygen use and survival in patients with advanced cancer and low oxygen saturation in home care.

Methods

We conducted a retrospective cohort study at a primary care practice in suburban Tokyo. Adult patients in home care with advanced cancer demonstrating first low oxygen saturation (less than 90%) detected in home visits were consecutively included in the study. Cox proportional hazards regression was used to investigate the effect of oxygen use on overall survival and survival at home, adjusted for systolic blood pressure, decreased level of consciousness, dyspnea, oral intake, performance status, and cardiopulmonary comorbidity.

Results

Of 433 identified patients with advanced cancer, we enrolled 137 patients (oxygen use, n = 35; no oxygen use, n = 102) who developed low oxygen saturation. In multivariable analysis, the adjusted hazard ratio (HR) of oxygen use was 0.68 (95% confidence interval 0.39–1.17) for death and 0.70 (0.38–1.27) for death at home. In patients with dyspnea, the HR was 0.35 (0.13–0.89) for death and 0.33 (0.11–0.96) for death at home; without dyspnea, it was 1.03 (0.49–2.17) for death and 0.84 (0.36–1.96) for death at home.

Conclusions

Oxygen use was not significantly associated with survival in patients with advanced cancer and low oxygen saturation, after adjusting for potential confounders. It may not be necessary to use oxygen for prolongation of survival in such patients, particularly in those without dyspnea.

Role of neuraxial drug delivery in cancer pain therapy

Opioids have long been the mainstay of cancer pain treatment and have been used without any consideration for their effect on cancer growth and long-term prognosis. There is now growing evidence that the continued use of opioids for this indication should be reviewed and even reconsidered. Although current evidence and literature covering this subject is mixed and does not yet allow for a clear determination to be made about safety, there is enough data to support the search for new treatment paradigms, beginning with anesthesia for oncologic surgery and management of cancer pain over the disease course.

Opioids and Cancer Mortality

OPINION STATEMENT

Opioids are the gold standard for the treatment of cancer-related pain. Preclinical studies have associated opioids with cancer progression and overall survival. In mice models, opioids have been shown to possess pro-tumor activity secondary to immunosuppression, migration of tumor cells, increased activity of vascular endothelial growth factor receptors, and angiogenesis leading to tumor progression. In contrast, opioids have also been associated with having antitumor activity by activation of apoptosis and phagocytosis. However, high-quality randomized controlled trials in humans that are focused on the association between opioids and survival in cancer patients are lacking, which underscores the importance of being cautious when interpreting the results of the preclinical studies. Cancer-related pain is complex and multifactorial and may worsen as the disease progresses leading to higher opioid utilization. Moreover, cancer pain by itself has been associated with poor survival. The survival in these advanced cancer patients taking opioids may be more likely to be associated with cancer progression and not the opioid use. Adequate treatment of cancer pain has the potential to improve quality of life and performance status, highlighting the importance of continuing to use opioids to manage pain efficiently. More research is clearly needed.

The relationship between pain, analgesics and survival in patients with advanced cancer; a secondary data analysis of the international European palliative care Cancer symptom study

PURPOSE

Opioids reduce cancer-related pain but an association with shorter survival is variably reported.

AIM

To investigate the relationship between pain, analgesics, cancer and survival within the European Palliative Care Cancer Symptom (EPCCS) study to help inform clinical decision making.

METHODS

Secondary analysis of the international prospective, longitudinal EPCCS study which included 1739 adults with advanced, incurable cancer receiving palliative care. In this secondary analysis, for all participants with date of death or last follow up, a multilevel Weibull survival analysis examined whether pain, analgesics, and other relevant variables are associated with time to death.

RESULTS

Date of death or last follow-up was available for 1404 patients (mean age 65.7 [SD:12.3];men 50%). Secondary analysis of this group showed the mean survival from baseline was 46.5 (SD:1.5) weeks (95% CI:43.6-49.3). Pain was reported by 76%; 60% were taking opioids, 51% non-opioid analgesics and 24% co-analgesics. Opioid-use was associated with decreased survival in the multivariable model (HR = 1.59 (95% CI:1.38-1.84), p < 0.001). An exploratory subgroup analysis of those with C-reactive protein (CRP) measures (n = 219) indicated higher CRP was associated with poorer survival (p = 0.001). In this model, the strength of relationship between survival and opioid-use weakened (p = 0.029).

CONCLUSION

Opioid-use and survival were associated; this relationship weakened in a small sensitivity-testing subgroup analysis adjusting for CRP. Thus, the observed relationship between survival and opioid-use may partly be due to tumour-related inflammation. Larger studies, measuring disease activity, are needed to confirm this finding to more accurately judge the benefits and risks of opioids in advanced progressive disease.

Optimizing Initial Intrathecal Drug Ratio for Refractory Cancer-Related Pain for Early Pain Relief. A Retrospective Monocentric Study

Objective

Intrathecal (IT) drug delivery has shown its efficiency in treating refractory cancer pain, but switching opioids from the systemic to the intrathecal route is a challenging phase. Moreover, associations are widely used and recommended. Few data deal with the initial dosage of each drug. Analyzing conversion factors and initial dosages used in intrathecal therapy seems essential to decreasing the length of titration and to delivering quick pain relief to patients.

Methods

We retrospectively analyzed data from consecutive adult patients implanted with an intrathecal device for cancer pain and treated at the Institut de Cancérologie de l’Ouest, in Angers, France, for four years. The main goal was to identify factors associated with early pain relief after intrathecal drug delivery system (IDDS) implantation.

Results

Of the 220 IDDS-treated patients, 70 (32%) experienced early pain relief (EaPR) and 150 (68%) delayed pain relief (DePR). Performance Status stage and initial IT ropivacaine:IT morphine ratio were the variables independently associated with EaPR. The best IT ropivacaine:IT morphine ratio to predict EaPR was 5:1, with a 73% (95% confidence interval [CI] = 64.8% to 79.6%) sensitivity and a 67.1% (95% CI = 54.9% to 77.9%) specificity. EaPR subjects experienced better pain relief (–84% vs –60% from baseline pain score, P < 0.0001), shorter length of hospitalization (7 vs 10 days, P < 0.0001), and longer survival (155 vs 82 days, P = 0.004).

Conclusions

Local anesthetic:morphine ratio should be considered when starting IDDS treatment. EaPR during the IT analgesia titration phase was associated with better pain relief and outcomes in patients with refractory cancer-related pain.

The Association Between Benzodiazepines and Survival in Patients With Cancer: A Systematic Review

CONTEXT

Patients with cancer often experience distressing symptoms such as anxiety or dyspnea, which can be managed with benzodiazepines; however, concerns regarding the impact of these drugs on survival may dissuade prescribing and compliance.

OBJECTIVES

We aimed to identify and appraise studies examining benzodiazepine use and survival in adults with cancer, to investigate the relationship and context of use.

METHODS

Systematic review of the international literature prepared according to preferred reporting items for systematic reviews. Comprehensive searches of the MEDLINE, Embase, PsycINFO, Cochrane Library, and AMED databases using medical subject heading and free-text search combinations with no date or language restrictions were undertook. Handsearching of references was conducted. Risk of bias of the included studies was assessed using Grading of Recommendations Assessment, Development, and Evaluation criteria.

RESULTS

Two thousand two hundred fifty-seven unique records were identified, with 18 meeting inclusion criteria, representing 4117 patients. All studies were very low quality. No study found an increase in mortality in association with benzodiazepine use, whereas two demonstrated an increase.

CONCLUSION

Existing evidence shows no association between benzodiazepine use in patients with cancer and decreased survival. None of the studies evaluated the association between benzodiazepine use and survival in earlier stages of cancer, and the quality of studies retrieved signifies a need for further robust studies to draw more definitive conclusions. Further investigation in patients with cancer using well-designed, high-quality research with survival as a primary outcome should be conducted.

Propofol Reduced Mammosphere Formation of Breast Cancer Stem Cells via PD-L1/Nanog In Vitro

Several researches revealed that propofol, a hypnotic intravenous anesthesia agent, could inhibit the cancer cell proliferation and tumor formation, which might affect cancer recurrence or metastasis and impact patients' prognosis. Cancer stem cells (CSCs) comprised a tiny fraction of tumor bulk and played a vital role in cancer recurrence and eventual mortality. This study investigates the effect of propofol on breast cancer stem cells (BCSCs) in vitro and the underlying molecular mechanisms. Tumor formation of CSCs was measured by mammosphere culture. Cultured BCSCs were exposed to different concentrations and durations of propofol. Cell proliferation and self-renewal capacity were determined by MTT assays. Expressions of PD-L1 and Nanog were measured using western blotting and real-time PCR. We knocked down the PD-L1 expression in MDA-MB-231 cells by lentivirus-mediated RNAi technique, and the mammosphere-forming ability of shControl and shPD-L1 under propofol treatment was examined. Mammosphere culture could enrich BCSCs. Compared with control, cells exposed to propofol for 24 h induced a larger number of mammosphere cells (P = 0.0072). Levels of PD-L1 and Nanog were downregulated by propofol. Compared with shControl stem cells, there was no significant difference in the inhibitory effect of propofol on the mammosphere-forming ability of shPD-L1 stem cells which indicated that the inhibition of propofol could disappear in PD-L1 knockdown breast stem cells. Propofol could reduce the mammosphere-forming ability of BCSCs in vitro. Mechanism experiments indicated that the inhibition of propofol in mammosphere formation of BCSCs might be mediated through PD-L1, which was important to maintain Nanog.

Regional anesthesia and analgesia in cancer care: is it time to break the bad news?

PURPOSE OF REVIEW

There is ongoing controversy regarding the tumor-protective effects of regional anesthesia in patients undergoing cancer surgery. Evidence of up-to-date systematic reviews will be presented alongside recent updates on the effects of opioids and local anesthetics.

RECENT FINDINGS

In recent years, the literature regarding the effects of regional anesthesia techniques on cancer recurrence has raised many unanswered questions. Ongoing randomized controlled trials may not be able to shed light on the controversial discussion regarding the tumor protective effects of regional anesthesia because the expected effect size and event rate in those studies may be overstated.Recent more refined animal data, provides no evidence to suggest that opioids promote cancer recurrence or facilitate the development of metastatic disease.In addition, local anesthetics have promising preclinical anticarcinogenic effects that extend beyond their voltage-gated sodium channel blocking properties and could be of therapeutic value.

SUMMARY

Cancer recurrence in patients undergoing surgery remains a global burden. Current evidence suggests that regional techniques, opioid analgesia and local anesthetics in onco-anesthesia may require a tailored individual approach due to the phenotypic and genotypic heterogeneity within and between different tumors. The authors surmise that future or ongoing randomized controlled trials regarding regional anesthesia techniques and cancer outcome may not be able to reproduce clear results, as it will be challenging to prove the efficacy of one single intervention (e.g. regional anesthesia) in an otherwise complex multifactorial perioperative oncological setting.

Impact of opioid use on health care utilization and survival in patients with newly diagnosed stage IV malignancies

PURPOSE

Patients with advanced cancers frequently experience pain. Opioids are commonly prescribed to treat cancer-related pain, but their use might be associated with undesirable consequences including adverse effects and tumor progression, resulting in increased heath care utilization and shorter survival. We examined these possibilities in a large cohort of patients diagnosed with ten common advanced malignancies.

METHODS

We identified 1386 newly diagnosed patients with stage IV non-hematologic malignancies from 2005 to 2013 and ascertained opioid utilization within 90 days of starting anti-cancer treatment using electronic medical record and tumor registry data. Opioid utilization was stratified into low opioid (LO; < 5 mg oral morphine equivalents (OME)/day) and high opioid (HO; ≥ 5 mg OME/day). Health care utilization included tallies of emergency room, urgent care, and inpatient visits. The association of opioid use, tumor type prognosis, age, and gender with overall survival was analyzed in univariate and multivariate models.

RESULTS

HO use patients (n = 624) had greater health care utilization compared to LO use patients (n = 762; p < 0.05). HO use patients also had shorter survival (median survival, 5.5 vs 12.4 months; p < 0.0001). On multivariate analysis, HO use remained associated with shorter overall survival (HR 1.4; 95% CI, 1.3-1.6; p < 0.0001) after adjusting for age, gender, and prognostic group.

CONCLUSIONS

In advanced cancer patients, HO use is associated with greater health care utilization and shorter survival. Prospective studies using opioid-sparing approaches are indicated, to confirm these retrospective findings and to evaluate if these undesirable effects associated with opioid use can be mitigated.

Updates in palliative care - overview and recent advancements in the pharmacological management of cancer pain

Pain is a common symptom in many types of cancer. Interdisciplinary team management, including pain assessment, explanation to the patient/family, treating the reversible, non-pharmacological treatments and reassessment are essential. This article focuses on the pharmacological management of cancer pain, and overviews and updates on the recent advances in this field. Both non-opioid and opioid analgesia as well as coanalgesics (adjuvants) are reviewed. Within non-opioid analgesia the risks of non-steroidal anti-inflammatory drugs (NSAIDs) are considered and recommendations for NSAIDs in patients at risk of gastrointestinal and cardiovascular toxicity are made. For opioid analgesics, side effects of opioids are discussed alongside practical guidance on opioid prescribing and converting between opioids. Newer drugs such as tapentadol are considered in this update. Amitriptyline, duloxetine, gabapentin and pregabalin, and the guidance for their use are reviewed in the coanalgesics (adjuvants) section.

Sinomenine attenuates cancer-induced bone pain via suppressing microglial JAK2/STAT3 and neuronal CAMKII/CREB cascades in rat models

Cancer-induced bone pain is one of the most severe types of pathological pain, which often occurs in patients with advanced prostate, breast, and lung cancer. It is of great significance to improve the therapies of cancer-induced bone pain due to the opioids' side effects including addiction, sedation, pruritus, and vomiting. Sinomenine, a traditional Chinese medicine, showed obvious analgesic effects on a rat model of chronic inflammatory pain, but has never been proven to treat cancer-induced bone pain. In the present study, we investigated the analgesic effect of sinomenine after tumor cell implantation and specific cellular mechanisms in cancer-induced bone pain. Our results indicated that single administration of sinomenine significantly and dose-dependently alleviated mechanical allodynia in rats with cancer-induced bone pain and the effect lasted for 4 h. After tumor cell implantation, the protein levels of phosphorylated-Janus family tyrosine kinase 2 (p-JAK2), phosphorylated-signal transducers and activators of transcription 3 (p-STAT3), phosphorylated-Ca2+/calmodulin-dependent protein kinase II (p-CAMKII), and phosphorylated-cyclic adenosine monophosphate response element-binding protein (p-CREB) were persistently up-regulated in the spinal cord horn. Chronic intraperitoneal treatment with sinomenine markedly suppressed the activation of microglia and effectively inhibited the expression of JAK2/STAT3 and CAMKII/CREB signaling pathways. We are the first to reveal that up-regulation of microglial JAK2/STAT3 pathway are involved in the development and maintenance of cancer-induced bone pain. Moreover, our investigation provides the first evidence that sinomenine alleviates cancer-induced bone pain by inhibiting microglial JAK2/STAT3 and neuronal CAMKII/CREB cascades.

Influence of opioids on immune function in patients with cancer pain: from bench to bedside

In patients with cancer, opioids are principally used for the management of acute surgical and chronic cancer-related pain. However, opioids have many non-analgesic effects, including direct and indirect effects on cancer cells and on anti-tumour immunity (NK cells, macrophages and T-cells). Direct effects on immune cells are manifested via opioid and non-opioid toll-like receptors, whereas indirect effects are manifested via the sympathetic nervous system and hypothalamic-pituitary-adrenal axis. Opioids can also decrease/alter immune cell infiltration into the tumour micro-environment. Animal models have shown that this is not a class effect, in that morphine and fentanyl suppress NK cell cytotoxicity; buprenorphine does not affect NK cell cytotoxicity, whereas tramadol increases NK cell cytotoxicity, reducing metastasis. In healthy individuals, morphine suppresses and fentanyl enhances NK cell cytotoxicity. In patients undergoing surgery, fentanyl decreased and tramadol increased NK cell cytotoxicity; clinical outcomes were not determined. Meta-analyses of opioid-sparing surgical studies report an association between improved recurrence-free and/or overall survival with regional/neuraxial anaesthesia compared with systemic opioids. In patients receiving opioids for non-surgical cancer-related pain, morphine has variable effects on immunity; clinical outcomes were not assessed. Although there is a potential association between systemic opioid administration and shorter survival in cancer patients with a prognosis of months to years, studies have not been designed to primarily assess survival, as a consequence of which causality cannot be apportioned. Pain is immunosuppressive, so analgesia is important. Opioids for cancer-related pain will continue to be recommended until definitive data on the effects of opioids on clinical outcomes in specific patient groups becomes available.

LINKED ARTICLES

This article is part of a themed section on Emerging Areas of Opioid Pharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.14/issuetoc.

The Role of Spinal GABAB Receptors in Cancer-Induced Bone Pain in Rats

Cancer-induced bone pain (CIBP) remains a major challenge in advanced cancer patients because of our lack of understanding of its mechanisms. Previous studies have shown the vital role of γ-aminobutyric acid B receptors (GABABRs) in regulating nociception and various neuropathic pain models have shown diminished activity of GABABRs. However, the role of spinal GABABRs in CIBP remains largely unknown. In this study, we investigated the specific cellular mechanisms of GABABRs in the development and maintenance of CIBP in rats. Our behavioral results show that acute as well as chronic intrathecal treatment with baclofen, a GABABR agonist, significantly attenuated CIBP-induced mechanical allodynia and ambulatory pain. The expression levels of GABABRs were significantly decreased in a time-dependent manner and colocalized mostly with neurons and a minority with astrocytes and microglia. Chronic treatment with baclofen restored the expression of GABABRs and markedly inhibited the activation of cyclic adenosine monophosphate (cAMP)-dependent protein kinase and the cAMP-response element-binding protein signaling pathway.

PERSPECTIVE

Our findings provide, to our knowledge, the first evidence that downregulation of GABABRs contribute to the development and maintenance of CIBP and restored diminished GABABRs attenuate CIBP-induced pain behaviors at least partially by inhibiting the protein kinase/cAMP-response element-binding protein signaling pathway. Therefore, spinal GABABR may become a potential therapeutic target for the management of CIBP.

The association between different opioid doses and the survival of advanced cancer patients receiving palliative care

Background

Concerns that opioids may hasten death can be a cause of the physicians’ reluctance to prescribe opioids, leading to inadequate symptom palliation. Our aim was to find if there was an association between different opioid doses and the survival of the cancer patients that participated in our palliative care program.

Methods

A retrospective study was conducted at Ramathibodi Hospital, Bangkok between January 2013 and December 2015. All of the cancer patients that were referred to palliative care teams by their primary physicians were included in the study. The study data included the patients’ demographics, disease status, comorbidities, functional status, type of services, cancer treatments, date of consultation, and the date of the patient’s death or last follow-up. The information concerning opioid use was collected by reviewing the medical records and this was converted to an oral morphine equivalent (OME), following a standard ratio. The time-varying covariate in the Cox regression analysis was applied in order to determine the association between different doses of opioids and patient survival.

Results

A total of 317 cancer patients were included in the study. The median (IQR) of the OME among our patients was 6.43 mg/day (0.53, 27.36). The univariate Cox regression analysis did not show any association between different opioid doses (OME ≤ 30 mg/day and > 30 mg/day) and the patients’ survival (p = 0.52). The PPS levels (p < 0.01), palliative care clinic visits (HR 0.32, 95%CI 0.24–0.43), home visits (HR 0.75, 95%CI 0.57–0.99), chemotherapy (HR 0.32, 95%CI 0.22–0.46), and radiotherapy (HR 0.53, 95%CI 0.36–0.78) were identified as factors that increased the probability of survival.

Conclusions

Our study has demonstrated that different opioid doses in advanced cancer patients are not associated with shortened survival period.

Advanced heart failure: an appraisal of the potential of levosimendan in this end-stage scenario and some related ethical considerations

INTRODUCTION

The later stages of heart failure are characterized by a steady decline in quality of life. Clinical priorities should be to maintain functional capacity and quality of life. In the absence of sufficient organs for transplantation, options include left ventricular assist devices and inotropic support. Areas covered: We examined data published in the last two decades on the use of inotropes and inodilators in advanced heart failure. Expert commentary: In the literature, use of conventional inotropes, including adrenergic agonists and phosphodiesterase inhibitors, appears to be suboptimal for achieving the clinical priorities of late-stage heart failure. Evidence suggests instead that the calcium-sensitizing inodilator levosimendan, administered intermittently, delivers improvements in functional capacity and quality of life and does so with no adverse impact on life expectancy. At a terminal or near-terminal stage of heart failure, the therapeutic philosophy should shift towards meeting patients' existential priorities rather than traditional heart failure-centric targets.

Targeting glia for bone cancer pain

INTRODUCTION

Bone cancer pain (BCP) remains to be a clinical challenge with limited pharmaceutical interventions. Therefore, novel therapeutic targets for the management of BCP are in desperate need. Recently, a growing body of evidence has suggested that glial cells may play a pivotal role in the pathogenesis of BCP. Areas covered: This review summarizes the recent progress in the understanding of glia in BCP and reveals the potential therapeutic targets in glia for BCP treatment. Expert opinion: Pharmacological interventions inhibiting the activation of glial cells, suppressing glia-derived proinflammatory cytokines, cell surface receptors, and the intracellular signaling pathways may be beneficial for the pain management of advanced cancer patients. However, these pharmacological interventions should not disrupt the normal function of glia cells since they play a vital supportive and protective role in the central nervous system.