Cannabinoids for adult cancer-related pain: systematic review and meta-analysis

Oncology: What You May Have Missed in 2023

Advances in oncology treatment methods have improved outcomes and quality of life for patients with cancer. However, care of these patients can be complex, and the contribution of physicians from different specialties is crucial. This article highlights important publications from 2023 on topics across a wide spectrum relating to the management of oncology patients. The literature was screened for significant new evidence that is relevant to internal medicine specialists and subspecialists whose focus is not oncology. Two articles address the importance of social interventions targeting end-of-life care for low-income and minority patients and the well-being of caregivers. Two additional articles address screening considerations in patients at risk for colorectal and lung cancer. Two more articles address safe use of hormone-related therapies to treat symptoms of menopause and prevent disease recurrence or progression in patients diagnosed with noninvasive breast neoplasia. Finally, several articles were included on topics related to COVID-19 vaccination in patients with cancer, use of cannabinoids for cancer pain control, chronic autoimmune adverse effects related to use of immune checkpoint inhibitors, and the incidence of second primary neoplasms.

Cannabis and Cannabinoids in Adults With Cancer: ASCO Guideline

PURPOSE

To guide clinicians, adults with cancer, caregivers, researchers, and oncology institutions on the medical use of cannabis and cannabinoids, including synthetic cannabinoids and herbal cannabis derivatives; single, purified cannabinoids; combinations of cannabis ingredients; and full-spectrum cannabis.

METHODS

A systematic literature review identified systematic reviews, randomized controlled trials (RCTs), and cohort studies on the efficacy and safety of cannabis and cannabinoids when used by adults with cancer. Outcomes of interest included antineoplastic effects, cancer treatment toxicity, symptoms, and quality of life. PubMed and the Cochrane Library were searched from database inception to January 27, 2023. ASCO convened an Expert Panel to review the evidence and formulate recommendations.

RESULTS

The evidence base consisted of 13 systematic reviews and five additional primary studies (four RCTs and one cohort study). The certainty of evidence for most outcomes was low or very low.

RECOMMENDATIONS

Cannabis and/or cannabinoid access and use by adults with cancer has outpaced the science supporting their clinical use. This guideline provides strategies for open, nonjudgmental communication between clinicians and adults with cancer about the use of cannabis and/or cannabinoids. Clinicians should recommend against using cannabis or cannabinoids as a cancer-directed treatment unless within the context of a clinical trial. Cannabis and/or cannabinoids may improve refractory, chemotherapy-induced nausea and vomiting when added to guideline-concordant antiemetic regimens. Whether cannabis and/or cannabinoids can improve other supportive care outcomes remains uncertain. This guideline also highlights the critical need for more cannabis and/or cannabinoid research.Additional information is available at www.asco.org/supportive-care-guidelines.

Natural Products Derived from Cannabis sativa for Pain Management

Cannabis sativa is one of the oldest medicinal plants in human history. Even ancient physicians from hundreds of years ago used Cannabis sativa to treat several conditions like pain. In the modern era, the research community, including health-care providers, have witnessed wide-scale changes in cannabis policy, legislation, and marketing, with a parallel increase in patient interest. A simple search in PubMed using "cannabis and pain" as keywords provides more than 2,400 articles, about 80% of which were published in the last 8-10 years. Several advancements have been achieved in understanding the complex chemistry of cannabis along with its multiple pharmacological activities. Preclinical data have demonstrated evidence for the promising potential of cannabis for pain management, and the continuous rise in the prevalence of pain increases the urgency to translate this into clinical practice. Despite the large body of cannabis literature, researchers still need to find rigorous answers for the questions about the efficacy and safety of cannabis in treatment of certain disorders such as pain. In the current chapter, we seek to present a critical overview about the current knowledge on cannabis with special emphasis on pain-related disorders.

Pain management for post-treatment survivors of complex cancers: a qualitative study of opioids and cannabis

Aim: We aimed to understand experiences with opioids and cannabis for post-treatment cancer survivors. Patients & methods: We conducted seven focus groups among head and neck and lung cancer survivors, using standard qualitative methodology to explore themes around 1) post-treatment pain and 2) utilization, perceived benefits and perceived harms of cannabis and opioids. Results & conclusion: Survivors (N = 25) experienced addiction fears, stigma and access challenges for both products. Opioids were often perceived as critical for severe pain. Cannabis reduced pain and anxiety for many survivors, suggesting that anxiety screening, as recommended in guidelines, would improve traditional pain assessment. Opioids and cannabis present complex harms and benefits for post-treatment survivors who must balance pain management and minimizing side effects.

Danish dog owners' use and the perceived effect of unlicensed cannabis products in dogs

The interest in the use of medical cannabis has increased in recent years in both human and veterinary fields. In Denmark, there are no veterinary-licensed medical cannabis or cannabinoid supplements, and it is illegal to prescribe or sell cannabinoids intended for the treatment of veterinary patients. This study aimed to explore the unlicensed cannabinoid use in Danish dogs, by questioning dog owners about usage, indication for use, way of purchase, and their perceived effect of the cannabinoid treatment. An anonymous online survey was distributed via social media. The total number of respondents were 2,002, of which 38% indicated using or having administered cannabinoids to their dog. The majority of the respondents confirming the use of cannabinoids (93%) had used cannabidiol drops/oil and only few (4%) reported using Δ9-tetrahydrocannabinol-based products. Most owners (67%) purchased the products online. The three most common indications for use were pain alleviation, behavioural issues, and allergy. When asked about the respondent-perceived effect the majority reported a good or very good effect. The indication with the highest percentage of owner-perceived positive effect (77%) was pain alleviation. This study shows that, despite no licensed veterinary cannabinoid products being available in Denmark, dog owners do supplement their dogs with cannabinoids and the majority of these perceive that the treatment had a positive effect. This supports the need for more evidence-based knowledge in veterinary cannabinoid therapy.

Tetrahydrocannabinol and Cannabidiol for Pain Treatment-An Update on the Evidence

In light of the current International Association for the Study of Pain (IASP) clinical practice guidelines (CPGs) and the European Society for Medical Oncology (ESMO) guidelines, the topic of cannabinoids in relation to pain remains controversial, with insufficient research presently available. Cannabinoids are an attractive pain management option due to their synergistic effects when administered with opioids, thereby also limiting the extent of respiratory depression. On their own, however, cannabinoids have been shown to have the potential to relieve specific subtypes of chronic pain in adults, although controversies remain. Among these subtypes are neuropathic, musculoskeletal, cancer, and geriatric pain. Another interesting feature is their effectiveness in chemotherapy-induced peripheral neuropathy (CIPN). Analgesic benefits are hypothesized to extend to HIV-associated neuropathic pain, as well as to lower back pain in the elderly. The aim of this article is to provide an up-to-date review of the existing preclinical as well as clinical studies, along with relevant systematic reviews addressing the roles of various types of cannabinoids in neuropathic pain settings. The impact of cannabinoids in chronic cancer pain and in non-cancer conditions, such as multiple sclerosis and headaches, are all discussed, as well as novel techniques of administration and relevant mechanisms of action.

Supporting gut health with medicinal cannabis in people with advanced cancer: potential benefits and challenges

The side effects of cancer therapy continue to cause significant health and cost burden to the patient, their friends and family, and governments. A major barrier in the way in which these side effects are managed is the highly siloed mentality that results in a fragmented approach to symptom control. Increasingly, it is appreciated that many symptoms are manifestations of common underlying pathobiology, with changes in the gastrointestinal environment a key driver for many symptom sequelae. Breakdown of the mucosal barrier (mucositis) is a common and early side effect of many anti-cancer agents, known to contribute (in part) to a range of highly burdensome symptoms such as diarrhoea, nausea, vomiting, infection, malnutrition, fatigue, depression, and insomnia. Here, we outline a rationale for how, based on its already documented effects on the gastrointestinal microenvironment, medicinal cannabis could be used to control mucositis and prevent the constellation of symptoms with which it is associated. We will provide a brief update on the current state of evidence on medicinal cannabis in cancer care and outline the potential benefits (and challenges) of using medicinal cannabis during active cancer therapy.

Cannabinoids in anesthesia and chronic pain: Where do we stand?

Cannabis derivatives have been conventionally employed globally for their curative and restorative properties for various ailments. However, its recreational use and consequent legal restrictions have substantially cramped its scientific research. An emerging interest regarding the profound therapeutic potential of cannabinoids has been observed among clinicians. Despite a rich cultural background, high-quality research on cannabinoids is lacking in the Indian scenario. This review readdresses the challenges on this front and brings an insight into the current status of cannabinoids and their utility in scientific exploration. Cannabinoids have a significant medicinal value in various clinical disorders. Its use so far has been based on scarce resources and corroborations, as evidence-based substantiation is limited. Through this review article, we emphasize the remarkable role enacted by cannabinoids in the treatment of various clinical disorders and an utterly significant need to formulate stringent research methodologies to promote its systematic investigation.

In Vitro Evidence of Selective Pro-Apoptotic Action of the Pure Cannabidiol and Cannabidiol-Rich Extract

Plant cannabinoids, secondary metabolites of species belonging to the Cannabis genus, can mimic the endocannabinoids' action and exert biological effects. Considering the contribution of the endocannabinoid system in cell cycle and apoptotic regulation, there is an interest in exploring the potential anti-cancer activities of natural and synthetic cannabinoids. Cannabidiol (CBD), an abundant plant cannabinoid, reveals a low affinity to cannabinoid receptors and, contrary to various cannabinoids, lacks psychoactive action. Here, we present the in vitro assessment of the pro-apoptototic potential of CBD-rich extracts of Cannabis sativa L. (eCBD) compared to purified CBD (pCBD). As demonstrated, both eCBD and pCBD decreased the viability of breast cancer cell line MDA-MB-231 and human prostate cancer cell line PC-3 in a concentration-dependent fashion. Endoplasmic reticulum stress-related apoptosis and morphological changes were induced only in low-serum conditions. Moreover, the effects of eCDB and pCDB were also assessed in non-malignant cell lines (MCF-10A and PNT2) with no alterations of viability noted, ultimately suggesting a selective action of CBD in tumor cells. The results suggest the possible involvement of reactive oxygen species in the response mechanism to eCBD and pCBD, but no clear pattern was observed. We also demonstrated significant changes in gene expression involved in apoptosis and cell cycle control upon extract treatment. Altogether, our study shows the potential of eCBD and pCBD as novel pro-apoptototic agents that can be considered promising in future preclinical and clinical testing.

Medical cannabis for refractory cancer-related pain in a specialised clinical service: a cross-sectional study

BACKGROUND AND OBJECTIVES

Cancer-related pain management in advanced stages presents a significant challenge that often requires a multidisciplinary approach. Although advancements in pharmacological and interventional therapies, a considerable number of patients still suffer from refractory pain, leading to unmet clinical needs. This study shares our experience with medical cannabis (MC) as a potential therapy for this specific population of patients with cancer-related refractory pain.

METHODS

In a cross-sectional study, 252 consecutive refractory cancer-related pain patients (mean age=61.71, SD=14.02, 47.6% males) filled out detailed self-report questionnaires. Of these, 126 patients (55%) were treated with MC and 105 patients (45%) were not.

RESULTS

Most patients received pain management from their oncologist, not a pain specialist. MC was mainly started for pain relief, sleep difficulties and anorexia. About 70% of patients reported subjective improvement from MC, with almost 40% reporting a significant improvement in coping with their illness. Side effects were generally mild, with fatigue and dizziness being the most common (21.78% and 23.46%, respectively). No patient required dedicated medical care for side effects. Of non-users, 65% had tried MC before and stopped due to lack of effectiveness or side effects (39.7% and 34.6%, respectively).

CONCLUSION

Refractory cancer pain necessitates innovative approaches. This registry highlights that MC can effectively improve symptoms in non-responsive patients, with favourable safety profiles for this vulnerable population.

Cannabinoids for symptom management in children with cancer: A systematic review and meta-analysis

BACKGROUND

Despite the widespread use of medical cannabis, little is known regarding the safety, efficacy, and dosing of cannabis products in children with cancer. The objective of this study was to systematically appraise the existing published literature for the use of cannabis products in children with cancer.

METHODS

This systematic review, registered with the International Prospective Register of Systematic Reviews (CRD42020187433), searched four databases: MEDLINE, Embase, PsycINFO, and the Cochrane Library. Abstracts and full texts were screened in duplicate. Data on types of cannabis products, doses, formulations, frequencies, routes of administration, indications, and clinical and demographic details as well as reported efficacy outcomes were extracted. Data on cannabinoid-related adverse events were also summarized.

RESULTS

Out of 34,611 identified citations, 19 unique studies with a total of 1927 participants with cancer were included: eight retrospective chart reviews, seven randomized controlled trials, two open-label studies, and two case reports. The included studies reported the use of various cannabis products for the management of symptoms. Cannabinoids were commonly used for the management of chemotherapy-induced nausea and vomiting (11 of 19 [58%]). In controlled studies, somnolence, dizziness, dry mouth, and withdrawal due to adverse events were more commonly associated with the use of cannabinoids. Across all included studies, no serious cannabis-related adverse events were reported.

CONCLUSIONS

Although there is evidence to support the use of cannabis for symptom management, in children with cancer, there is a lack of rigorous evidence to inform the dosing, safety, and efficacy of cannabinoids. Because of the increasing interest in using cannabis, there is an urgent need for more research on medical cannabis in children with cancer.

Cannabis in Cancer Survivors Who Report High Impact Chronic Pain: Findings from a 1500+ Patient Survey

BACKGROUND

Chronic pain in cancer survivors negatively impacts quality of life. This study sought to investigate the relationship between high-impact chronic pain (HICP) -- defined as chronic pain that limits life or work activities on most days or every day in the past 3 months -- and cannabis in cancer survivors.

METHODS

An electronic survey was developed in conjunction with the National Cancer Institute Comprehensive Cancer Centers in the United States. This survey was distributed to cancer survivors within a multi-site, single institution setting.

RESULTS

The survey response rate was 23.0% (2304/10,000); 72.7% of these patients (1676/2304) did in fact have a confirmed cancer diagnosis. Among these cancer survivors, 16.5% (unweighted 278/1676) had HICP, and 12.4% (208/1676) reported cannabis use since their cancer diagnosis. The prevalence of past 30-day cannabis use was 12.3% (206/1676). Compared to cancer survivors without pain, those with HICP were more likely to believe in the benefits of cannabis (unweighted 92.1% vs. 74.7%; age-adjusted odds ratio [OR] = 3.1; 95% CI: 1.9-5.1) and less likely to believe in its risks (unweighted 48.2% vs. 58.4%; age-adjusted OR = 0.6; 95% CI: 0.4-0.7).

CONCLUSIONS

Cancer survivors with HICP have a higher prevalence of cannabis use compared to those patients without pain. More research is needed to advance pain and symptom management among cancer survivors and to identify clinical scenarios in which benefit is greater than potential harm.

Cannabis use among adults undergoing cancer treatment

BACKGROUND

Little is known about the risks and benefits of cannabis use in the context of cancer care. This study characterized the prevalence, reasons for use, and perceived benefits of cannabis and compared symptoms and perceived risks between those who reported past 30-day cannabis use and those who did not.

METHODS

Adults undergoing cancer treatment at a National Cancer Institute-designated cancer center completed measures of sociodemographic characteristics, cannabis use, use modalities, reasons for use, perceived harms/benefits of use, physical and psychological symptoms, and other substance/medication use. Analyses compared patients who used or did not use cannabis in the past 30 days.

RESULTS

Participants (N = 267) were 58 years old on average, primarily female (70%), and predominantly White (88%). Over a quarter of respondents (26%) reported past 30-day cannabis use, and among those, 4.5% screened positive for cannabis use disorder. Participants who used cannabis most often used edibles (65%) or smoked cannabis (51%), and they were younger and more likely to be male, Black, and disabled, and to have lower income and Medicaid insurance than participants who did not use cannabis. Those who used cannabis reported more severe symptoms and perceived cannabis as less harmful than those who did not use cannabis. The most common medical reasons for cannabis use were pain, cancer, sleep problems, anxiety, nausea/vomiting, and poor appetite. Participants reported the greatest cannabis-related symptom relief from sleep problems, nausea/vomiting, headaches, pain, muscle spasms, and anxiety.

CONCLUSIONS

Patients with cancer who used cannabis perceived benefits for many symptoms, although they showed worse overall symptomatology.

PLAIN LANGUAGE SUMMARY

Among adults undergoing cancer treatment, 26% reported cannabis use in the past 30 days. Those who used cannabis were more likely to be male and disabled and to have lower income and Medicaid insurance than those who did not use cannabis. Participants most commonly reported using cannabis for pain, cancer, sleep, anxiety, and nausea/vomiting and reported the greatest perceived benefits for sleep, nausea/vomiting, headaches, pain, muscle spasms, and anxiety, yet participants who used cannabis also reported feeling worse physically and psychologically compared to those who did not use cannabis. Participants who used cannabis were more likely to report that cannabis was less risky to their health than alcohol, smoking, and opioids than those who did not use cannabis.

Medicinal Cannabis and Implications for Workplace Health and Safety: Scoping Review of Systematic Reviews

PURPOSE

Although medicinal cannabis is prescribed for conditions such as pain, epilepsy, nausea and vomiting during cancer treatment, evidence about associated adverse side effects is still evolving. Because adverse events (AEs) might impact the performance of workers, it is important to consider their implications on workplace health and safety (WHS). This study aimed to map the types and prevalence of the AEs associated with medical cannabis and articulate how those events could impact WHS.

METHODS

A scoping review of systematic reviews and/or meta-analyses published between 2015 and March 2021 was performed to identify the AEs of medicinal cannabis in adults. Publications in English and full text available online were collected from Embase, MEDLINE, PsychINFO, PubMed, Scopus, and Web of Science.

RESULTS

Of 1,326 papers identified from the initial search, 31 met the inclusion criteria and were analyzed. The studies reported various AEs with the most predominant being sedation, nausea/vomiting, dizziness, and euphoria. Acute and chronic pain was the most prevalent disorder under review.

CONCLUSIONS

Adverse events associated with the use of medicinal cannabis could increase workplace risks, including decreased alertness and reaction times, increased absenteeism, reduced ability to safely drive or operate machinery and an increased probability of falling. Focused research into the risk to workers and workplaces from the use of medical cannabis and related human performance impairment is urgently warranted.

Cannabis use among recently treated cancer patients: perceptions and experiences

PURPOSE

To characterize cannabis use among cancer patients, we aimed to describe 1) patterns of cannabis use across multiple cancer sites; 2) perceived goals, benefits, harms of cannabis; and 3) communication about cannabis.

METHODS

Patients with 9 different cancers treated at Memorial Sloan Kettering Cancer Center between March and August 2021 completed an online or phone survey eliciting cannabis use, attitudes, and communication about cannabis. Multivariable logistic regression estimated the association of cancer type and cannabis use, adjusting for sociodemographic characteristics and prior cannabis use.

RESULTS

Among 1258 respondents, 31% used cannabis after diagnosis, ranging from 25% for lung cancer to 59% for testicular cancer. Characteristics associated with cannabis use included younger age, lower education level, and cancer type. In multivariable analysis, compared to lung cancer patients, gastrointestinal cancer patients were more likely to use cannabis (odds ratio [OR] 2.64, 95% confidence interval [CI] 1.25-5.43). Cannabis use in the year prior to diagnosis was strongly associated with cannabis use after diagnosis (OR 19.13, 95% CI 11.92-30.72). Among users, reasons for use included difficulty sleeping (48%); stress, anxiety, or depression (46%); and pain (42%). Among respondents who used cannabis to improve symptoms, 70-90% reported improvement; < 5% reported that any symptom worsened. Only 25% discussed cannabis with healthcare providers.

CONCLUSIONS

Almost a third of cancer patients use cannabis, largely for symptom management. Oncologists may not know about their patients' cannabis use. To improve decision making about cannabis use during cancer care, research is needed to determine benefits and harms of cannabis use.

Cancer Pain Management: A Narrative Review of Current Concepts, Strategies, and Techniques

Pain is frequently reported during cancer disease, and it still remains poorly controlled in 40% of patients. Recent developments in oncology have helped to better control pain. Targeted treatments may cure cancer disease and significantly increase survival. Therefore, a novel population of patients (cancer survivors) has emerged, also enduring chronic pain (27.6% moderate to severe pain). The present review discusses the different options currently available to manage pain in (former) cancer patients in light of progress made in the last decade. Major progress in the field includes the recent development of a chronic cancer pain taxonomy now included in the International Classification of Diseases (ICD-11) and the update of the WHO analgesic ladder. Until recently, cancer pain management has mostly relied on pharmacotherapy, with opioids being considered as the mainstay. The opioids crisis has prompted the reassessment of opioids use in cancer patients and survivors. This review focuses on the current utilization of opioids, the neuropathic pain component often neglected, and the techniques and non-pharmacological strategies available which help to personalize patient treatment. Cancer pain management is now closer to the management of chronic non-cancer pain, i.e., "an integrative and supportive pain care" aiming to improve patient's quality of life.

Cannabis use is associated with pain severity and interference among cancer survivors

Context

Cannabis use for symptom management among individuals with cancer is increasingly common.

Objectives

We sought to describe the 1) prevalence and characteristics of cannabis use, 2) perceived therapeutic benefits of cannabis use, and 3) examine how use of cannabis was associated with self-reported pain, mood, and general health outcomes among a representative sample of patients treated at NCI designated OHSU Knight Cancer Institute.

Methods

We conducted a population-based, cross-sectional survey developed in conjunction with 11 other NCI designated cancer centers and distributed to eligible individuals. The survey inquired about characteristics of cannabis use, perception of therapeutic benefits, pain, mood, and general health. Responses were population weighted. We examined the association of cannabis use with self-reported pain, mood, and general health using logistic regression controlling for relevant sociodemographic and clinical characteristics.

Results

523 individuals were included in our analytic sample. 54% endorsed using cannabis at any time since their cancer diagnosis and 42% endorsed using cannabis during active treatment. The most endorsed reasons for use included: sleep disturbance (54.7%), pain (47.1%), and mood (42.6%). We found moderate pain was associated with more than a 2-fold (OR = 2.4 [95% CI = 1.3-4.6], p = 0.002) greater likelihood of self-reported cannabis use. Depressed mood or general health were not associated with cannabis use.

Conclusions

In a state with medical and recreational cannabis legislation, a high number of cancer survivors report cannabis use. Those with pain were more likely to use cannabis. Oncologists should be aware of this trend and assess use of cannabis when managing long-term symptoms of cancer and its treatments.

Cannabis-based medicines and medical cannabis for adults with cancer pain

BACKGROUND

Pain is a common symptom in people with cancer; 30% to 50% of people with cancer will experience moderate-to-severe pain. This can have a major negative impact on their quality of life. Opioid (morphine-like) medications 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. Pain is not sufficiently relieved by opioid medications in 10% to 15% of people with cancer. In people with insufficient relief of cancer pain, new analgesics are needed to effectively and safely supplement or replace opioids.

OBJECTIVES

To evaluate the benefits and harms of cannabis-based medicines, including medical cannabis, for treating pain and other symptoms in adults with cancer compared to placebo or any other established analgesic for cancer pain.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 26 January 2023.

SELECTION CRITERIA

We selected double-blind randomised, controlled trials (RCT) of medical cannabis, plant-derived and synthetic cannabis-based medicines against placebo or any other active treatment for cancer pain in adults, with any treatment duration and at least 10 participants per treatment arm.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. The primary outcomes were 1. proportions of participants reporting no worse than mild pain; 2. Patient Global Impression of Change (PGIC) of much improved or very much improved and 3. withdrawals due to adverse events. Secondary outcomes were 4. number of participants who reported pain relief of 30% or greater and overall opioid use reduced or stable; 5. number of participants who reported pain relief of 30% or greater, or 50% or greater; 6. pain intensity; 7. sleep problems; 8. depression and anxiety; 9. daily maintenance and breakthrough opioid dosage; 10. dropouts due to lack of efficacy; 11. all central nervous system adverse events. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We identified 14 studies involving 1823 participants. No study assessed the proportions of participants reporting no worse than mild pain on treatment by 14 days after start of treatment. We found five RCTs assessing oromucosal nabiximols (tetrahydrocannabinol (THC) and cannabidiol (CBD)) or THC alone involving 1539 participants with moderate or severe pain despite opioid therapy. The double-blind periods of the RCTs ranged between two and five weeks. Four studies with a parallel design and 1333 participants were available for meta-analysis. There was moderate-certainty evidence that there was no clinically relevant benefit for proportions of PGIC much or very much improved (risk difference (RD) 0.06, 95% confidence interval (CI) 0.01 to 0.12; number needed to treat for an additional beneficial outcome (NNTB) 16, 95% CI 8 to 100). There was moderate-certainty evidence for no clinically relevant difference in the proportion of withdrawals due to adverse events (RD 0.04, 95% CI 0 to 0.08; number needed to treat for an additional harmful outcome (NNTH) 25, 95% CI 16 to endless). There was moderate-certainty evidence for no difference between nabiximols or THC and placebo in the frequency of serious adverse events (RD 0.02, 95% CI -0.03 to 0.07). There was moderate-certainty evidence that nabiximols and THC used as add-on treatment for opioid-refractory cancer pain did not differ from placebo in reducing mean pain intensity (standardised mean difference (SMD) -0.19, 95% CI -0.40 to 0.02). There was low-certainty evidence that a synthetic THC analogue (nabilone) delivered over eight weeks was not superior to placebo in reducing pain associated with chemotherapy or radiochemotherapy in people with head and neck cancer and non-small cell lung cancer (2 studies, 89 participants, qualitative analysis). Analyses of tolerability and safety were not possible for these studies. There was low-certainty evidence that synthetic THC analogues were superior to placebo (SMD -0.98, 95% CI -1.36 to -0.60), but not superior to low-dose codeine (SMD 0.03, 95% CI -0.25 to 0.32; 5 single-dose trials; 126 participants) in reducing moderate-to-severe cancer pain after cessation of previous analgesic treatment for three to four and a half hours (2 single-dose trials; 66 participants). Analyses of tolerability and safety were not possible for these studies. There was low-certainty evidence that CBD oil did not add value to specialist palliative care alone in the reduction of pain intensity in people with advanced cancer. There was no difference in the number of dropouts due to adverse events and serious adverse events (1 study, 144 participants, qualitative analysis). We found no studies using herbal cannabis.

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that oromucosal nabiximols and THC are ineffective in relieving moderate-to-severe opioid-refractory cancer pain. There is low-certainty evidence that nabilone is ineffective in reducing pain associated with (radio-) chemotherapy in people with head and neck cancer and non-small cell lung cancer. There is low-certainty evidence that a single dose of synthetic THC analogues is not superior to a single low-dose morphine equivalent in reducing moderate-to-severe cancer pain. There is low-certainty evidence that CBD does not add value to specialist palliative care alone in the reduction of pain in people with advanced cancer.

Alternative pain management via endocannabinoids in the time of the opioid epidemic: Peripheral neuromodulation and pharmacological interventions

The use of opioids in pain management is hampered by the emergence of analgesic tolerance, which leads to increased dosing and side effects, both of which have contributed to the opioid epidemic. One promising potential approach to limit opioid analgesic tolerance is activating the endocannabinoid system in the CNS, via activation of CB1 receptors in the descending pain inhibitory pathway. In this review, we first discuss preclinical and clinical evidence revealing the potential of pharmacological activation of CB1 receptors in modulating opioid tolerance, including activation by phytocannabinoids, synthetic CB1 receptor agonists, endocannabinoid degradation enzyme inhibitors, and recently discovered positive allosteric modulators of CB1 receptors. On the other hand, as non-pharmacological pain relief is advocated by the US-NIH to combat the opioid epidemic, we also discuss contributions of peripheral neuromodulation, involving the electrostimulation of peripheral nerves, in addressing chronic pain and opioid tolerance. The involvement of supraspinal endocannabinoid systems in peripheral neuromodulation-induced analgesia is also discussed. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.

MASCC guideline: cannabis for cancer-related pain and risk of harms and adverse events

BACKGROUND

Approximately 18% of patients with cancer use cannabis at one time as palliation or treatment for their cancer. We performed a systematic review of randomized cannabis cancer trials to establish a guideline for its use in pain and to summarize the risk of harm and adverse events when used for any indication in cancer patients.

METHODS

A systematic review of randomized trials with or without meta-analysis was carried out from MEDLINE, CCTR, Embase, and PsychINFO. The search involved randomized trials of cannabis in cancer patients. The search ended on November 12, 2021. The Jadad grading system was used for grading quality. Inclusion criteria for articles were randomized trials or systematic reviews of randomized trials of cannabinoids versus either placebo or active comparator explicitly in adult patients with cancer.

RESULTS

Thirty-four systematic reviews and randomized trials met the eligibility criteria for cancer pain. Seven were randomized trials involving patients with cancer pain. Two trials had positive primary endpoints, which could not be reproduced in similarly designed trials. High-quality systematic reviews with meta-analyses found little evidence that cannabinoids are an effective adjuvant or analgesic to cancer pain. Seven systematic reviews and randomized trials related to harms and adverse events were included. There was inconsistent evidence about the types and levels of harm patients may experience when using cannabinoids.

CONCLUSION

The MASCC panel recommends against the use of cannabinoids as an adjuvant analgesic for cancer pain and suggests that the potential risk of harm and adverse events be carefully considered for all cancer patients, particularly with treatment with a checkpoint inhibitor.

Cannabis Use in Patients Seen in an Academic Radiation Oncology Department

PURPOSE

Cannabis use rates are increasing in the United States. Patients with cancer use cannabis for many reasons, even without high-quality supporting data. This study sought to characterize cannabis use among patients seen in radiation oncology in a state that has legalized adult nonmedical use cannabis and to identify key cannabis-related educational topics.

METHODS AND MATERIALS

Cannabis history was documented by providers using a structured template at patient visits in an academic radiation oncology practice October 2020 to November 2021. Cannabis use data, including recency/frequency of use, reason, and mode of administration, were summarized, and logistic regression was used to explore associations between patient and disease characteristics and recent cannabis use. A multivariable model employed stepwise variable selection using the Akaike Information Criterion.

RESULTS

Of 3143 patients total, 91 (2.9%) declined to answer cannabis use questions, and 343 (10.9%) endorsed recent use (≤1 month ago), 235 (7.5%) noted nonrecent use (>1 month ago), and 2474 (78.7%) denied history of cannabis use. In multivariable analyses, those ≥50 years old (odds ratio [OR], 0.409; 95% confidence interval [CI], 0.294-0.568; P < .001) or with history of prior courses of radiation (OR, 0.748; 95% CI, 0.572-0.979; P = .034) were less likely, and those with a mental health diagnosis not related to substance use (OR, 1.533; 95% CI, 1.171-2.005; P = .002) or who smoked tobacco (OR, 3.003; 95% CI, 2.098-4.299; P < .001) were more likely to endorse recent cannabis use. Patients reported pain, insomnia, and anxiety as the most common reasons for use. Smoking was the most common mode of administration.

CONCLUSIONS

Patients are willing to discuss cannabis use with providers and reported recent cannabis use for a variety of reasons. Younger patients new to oncologic care and those with a history of mental illness or tobacco smoking may benefit most from discussions about cannabis given higher rates of cannabis use in these groups.

Do We Have Structure, Process and Outcomes to Support Cannabis as Supportive Therapy in Cancer?

Cannabis is becoming more popular and more available in the United States. It has been approved for use by multiple states for various conditions and several states now allow recreational cannabis. We explore the structure of cannabis distribution, the process of acquisition, outcomes, and the safety of cannabis in the United States.

Phase IIb Randomized, Placebo-Controlled, Dose-Escalating, Double-Blind Study of Cannabidiol Oil for the Relief of Symptoms in Advanced Cancer (MedCan1-CBD)

PURPOSE

To determine whether cannabidiol (CBD) oil can improve symptom distress in patients with advanced cancer receiving palliative care.

METHODS

Participants were adults with advanced cancer and symptom distress (Edmonton Symptom Assessment Scale [ESAS] total score of ≥ 10/90) who received titrated CBD oil 100 mg/mL, 0.5 mL once daily to 2 mL three times a day, or matched placebo for 28 days. The primary outcome was ESAS total symptom distress score (TSDS) at day 14. Response was defined as a decrease in TSDS by ≥ 6 at day 14. Secondary outcomes were ESAS TSDS over time, individual symptom scores, patient-determined effective dose, opioid use, Global Impression of Change, depression, anxiety, quality of life, and adverse events.

RESULTS

Of the 144 patients randomly assigned, the planned sample size of 58 participants on CBD and 63 on placebo reached the primary analysis point (day 14). The unadjusted change in TSDS from baseline to day 14 was -6.2 (standard deviation, 14.5) for placebo and -3.0 (standard deviation, 15.2) for CBD with no significant difference between arms (P = .24). Similarly, there was no detected difference in proportion of responders (placebo: 37 of 63 [58.7%], CBD: 26 of 58 [44.8%], P = .13). All components of ESAS improved (fell) over time with no difference between arms. The median dose of participant-selected CBD was 400 mg per day with no correlation with opioid dose. There was no detectable effect of CBD on quality of life, depression, or anxiety. Adverse events did not differ significantly between arms apart from dyspnea that was more common with CBD. Most participants reported feeling better or much better at days 14 (53% CBD and 65% placebo) and 28 (70% CBD and 64% placebo).

CONCLUSION

CBD oil did not add value to the reduction in symptom distress provided by specialist palliative care alone.

Attitudes and Knowledge Regarding the Therapeutic Use of Cannabinoids among Community Pharmacists: A Pilot Cross-Sectional Study in Amman, Jordan

There is an increasing interest in the therapeutic use of cannabis worldwide, with a number of cannabinoid-derived drugs currently approved by the Food and Drug Administration (FDA) for certain indications. This study was conducted via a printed questionnaire and aimed to explore the attitudes and knowledge regarding the therapeutic use of cannabis and cannabinoids among community pharmacists residing in Amman, Jordan. The results revealed a neutral to low agreement level regarding the medical usefulness of cannabis; however, a higher agreement level was observed for FDA-approved cannabinoid-derived drugs. The majority of the participants reported that they did not learn enough regarding cannabinoids, do not adequately remember what they have learned, and do not actively look for information after graduation. The average percentages of correct identification of cannabis/cannabinoid FDA-approved drug indications, common adverse effects, interacting drugs, and cautions/contraindications were 40.6%, 53%, 49.4%, and 57.3%, respectively, with an overall correct identification rate of 51.1% of the participants. In conclusion, the results indicate an inadequate level of knowledge with a significant room for improvement regarding the various aspects of cannabinoid pharmacology.

Impacts of medical and non-medical cannabis on the health of older adults: Findings from a scoping review of the literature

BACKGROUND

Cannabis legalization has enabled increased consumption in older adults. Age-related mental, physical, and physiological changes may lead to differences in effects of cannabis in older adults compared to younger individuals.

OBJECTIVE

To perform a scoping review to map the evidence regarding the health effects of cannabis use for medical and non-medical purposes in older adults.

METHODS

Electronic databases (MEDLINE, Embase, PsycINFO, Cochrane Library) were searched for systematic reviews (SRs), randomized controlled trials (RCTs) and non-randomized/observational studies (NRSs) assessing the health effects and associations of cannabis use (medical or non-medical) in adults ≥ 50 years of age. Included studies met age-related inclusion criteria or involved a priori identified health conditions common among older adults. Records were screened using a liberal accelerated approach and data charting was performed independently by two reviewers. Descriptive summaries, structured tables, effect direction plots and bubble plots were used to synthesize study findings.

FINDINGS

From 31,393 citations, 133 publications describing 134 unique studies (26 SRs, 36 RCTs, 72 NRSs) were included. Medical cannabis had inconsistent therapeutic effects in specific patient conditions (e.g., end-stage cancer, dementia), with a number of studies suggesting possible benefits while others found no benefit. For medical cannabis, harmful associations outnumbered beneficial, and RCTs reported more negative effects than NRSs. Cannabis use was associated with greater frequencies of depression, anxiety, cognitive impairment, substance use and problematic substance use, accidents/injuries, and acute healthcare use. Studies often were small, did not consistently assess harms, and did not adjust for confounding.

DISCUSSION

The effects of medical cannabis are inconsistent within specific patient conditions. For older adults, generally, the available evidence suggests cannabis use may be associated with greater frequencies of mental health issues, substance use, and acute healthcare use, and the benefit-to-risk ratio is unclear. Studies with a balanced assessment of benefits and harms may guide appropriate public health messaging to balance the marketing pressures of cannabis to older adults.

Cannabinoids versus placebo for pain: A systematic review with meta-analysis and Trial Sequential Analysis

OBJECTIVES

To assess the benefits and harms of cannabinoids in participants with pain.

DESIGN

Systematic review of randomised clinical trials with meta-analysis, Trial Sequential Analysis, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

DATA SOURCES

The Cochrane Library, MEDLINE, Embase, Science Citation Index, and BIOSIS.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Published and unpublished randomised clinical trials comparing cannabinoids versus placebo in participants with any type of pain.

MAIN OUTCOME MEASURES

All-cause mortality, pain, adverse events, quality of life, cannabinoid dependence, psychosis, and quality of sleep.

RESULTS

We included 65 randomised placebo-controlled clinical trials enrolling 7017 participants. Fifty-nine of the trials and all outcome results were at high risk of bias. Meta-analysis and Trial Sequential Analysis showed no evidence of a difference between cannabinoids versus placebo on all-cause mortality (RR 1.20; 98% CI 0.85 to 1.67; P = 0.22). Meta-analyses and Trial Sequential Analysis showed that cannabinoids neither reduced acute pain (mean difference numerical rating scale (NRS) 0.52; 98% CI -0.40 to 1.43; P = 0.19) or cancer pain (mean difference NRS -0.13; 98% CI -0.33 to 0.06; P = 0.1) nor improved quality of life (mean difference -1.38; 98% CI -11.81 to 9.04; P = 0.33). Meta-analyses and Trial Sequential Analysis showed that cannabinoids reduced chronic pain (mean difference NRS -0.43; 98% CI -0.72 to -0.15; P = 0.0004) and improved quality of sleep (mean difference -0.42; 95% CI -0.65 to -0.20; P = 0.0003). However, both effect sizes were below our predefined minimal important differences. Meta-analysis and Trial Sequential Analysis indicated that cannabinoids increased the risk of non-serious adverse events (RR 1.20; 95% CI 1.15 to 1.25; P < 0.001) but not serious adverse events (RR 1.18; 98% CI 0.95 to 1.45; P = 0.07). None of the included trials reported on cannabinoid dependence or psychosis.

CONCLUSIONS

Cannabinoids reduced chronic pain and improved quality of sleep, but the effect sizes are of questionable importance. Cannabinoids had no effects on acute pain or cancer pain and increased the risks of non-serious adverse events. The harmful effects of cannabinoids for pain seem to outweigh the potential benefits.

Clinical Research Evidence Supporting Administration and Dosing Recommendations of Medicinal Cannabis as Analgesic in Cancer Patients

The analgesic potential of Cannabis sativa L.-based medicinal cannabis products for treatment of cancer associated chronic pains has gained increased interest in recent years. To ensure a controlled distribution of these products and investigate their therapeutic potential, several countries have established so-called pilot trials. Many doctors, however, are hesitant to prescribe medicinal cannabis primarily due to lack of research evidence regarding the products' efficacy, safety and thus questionable dosing guidelines. This review aims to elucidate clinical research supporting administration of medicinal cannabis in cancer patients for analgesic purposes. The cannabinoids' effects on the endocannabinoid system (ECS) and its implication in pain regulation is included to illustrate the complexity related to this research field. Published clinical studies on medicinal cannabis primarily consist of observational studies and only one pilot randomized controlled trial (RCT), where more RCTs exist on the cannabis-based product, Sativex^® (GW Pharma Ltd., Cambridge, UK). The studies indicate analgesic potential, however non-significantly, for most patients and with acceptable safety profile. Summarizing, high-quality RCTs are scarce in this research field, and the limitations of the observational studies complicates interpretation of clinical outcomes. Despite discrepancy among the studies, they do show indications for administration and dosing regimens providing analgesic effects for some cancer patients.

Cannabis in Palliative Care: A Systematic Review of Current Evidence

CONTEXT

Palliative care aims to improve the quality of life in patients with incurable illness. Medicinal cannabis (MC) has been used in the palliative care setting to address multiple symptoms in patients.

OBJECTIVES

To evaluate the full scope of available literature investigating the effects and potential harms of MC on symptom management and quality of life in palliative care.

METHODS

PubMed, Embase, The Cochrane Library and clinicaltrials.gov were searched for eligible articles, published between 1960 and September 9, 2021. Quality of the evidence was assessed in accordance with Grading of Recommendations, Assessment, Development and Evaluations. Risk of bias was assessed using the RoB 2 tool for randomised controlled trials and the Risk of Bias in Non-randomized Studies-of Interventions (ROBINS-I) tool for non-randomized trials.

RESULTS

Fifty-two studies (20 randomised; 32 non-randomised) with 4786 participants diagnosed with cancer (n = 4491), dementia (n = 43), AIDS (n = 235), spasticity (n = 16), NORSE syndrome (n = 1) were included. The quality of evidence was 'very low' or 'low' for all studies, and low for only two randomised controlled trials. Positive treatment effects (statistical significance with P < 0.05) were seen for some MC products in pain, nausea and vomiting, appetite, sleep, fatigue, chemosensory perception and paraneoplastic night sweats in patients with cancer, appetite and agitation in patients with dementia and appetite, nausea and vomiting in patients with AIDS. Meta-analysis was unable to be performed due to the wide range of cannabis products used and the heterogeneity of the study outcomes.

CONCLUSION

While positive treatment effects have been reported for some MC products in the palliative care setting, further high quality evidence is needed to support recommendations for its use in clinical practice.

Pilot clinical and pharmacokinetic study of Δ9-Tetrahydrocannabinol (THC)/Cannabidiol (CBD) nanoparticle oro-buccal spray in patients with advanced cancer experiencing uncontrolled pain

This pilot study aimed to assess the safety, tolerability, pharmacokinetics and exploratory analgesic effect of a novel water-soluble oro-buccal nanoparticle spray of a cannabis-based medicine (MDCNS-01) in patients with advanced incurable malignancy with unrelieved pain from opioid analgesic. The study was a non-blinded single arm 2 stage study. Stage I was a single escalating dose (n = 5) [2.5 mg Δ9-THC and 2.5 mg CBD) versus a 3-fold escalated dose. Stage II was an up-titrated dose in patients with advanced cancers and intractable pain (n = 25). During Stage I with an increased cannabis-based medicine dose, maximum observed plasma concentrations of cannabinoids were dose dependant. The water-soluble formulation in the current study resulted in a higher median (min, max) systemic exposure of Δ9-THC than CBD (AUC from 2.5 mg each of Δ9-THC and CBD, was 1.71 ng mL.h-1 (1.1, 6.6) and 0.65 ng mL.h-1 (0.49, 4.1), respectively). During stage II a subgroup of patients diagnosed with breast and prostate cancers with bone metastases, had the highest mean pain score improvement from baseline of 40% (unadjusted) and 33% (adjusted for rescue medication use). For all patients the most reported adverse events were mild or moderate drowsiness affecting 11 (44%) and 4 (6%) patients, respectively, and nausea and vomiting that affected 18 (72%) patients. The water-soluble cannabis-based medicine provided acceptable bioavailability for Δ9-THC/CBD, appeared safe and tolerable in advanced incurable cancers with uncontrolled pain with preliminary evidence of analgesic efficacy.

Cannabis medicinal: puntos críticos para su uso clínico

El cannabis se ha utilizado desde la antigüedad con fines recreativos y medicinales. Es una fuente muy rica de compuestos químicos, la mayoría denominados fitocannabinoides, que tienen una variedad de efectos fisiológicos, principalmente por su unión a receptores cannabinoides endógenos como el CB1 y CB2, entre otros.El cannabis tiene propiedades terapéuticas potenciales y sus preparaciones se han utilizado como remedios tradicionales para tratar el dolor y la emesis. Los cannabinoides sintéticos se utilizan clínicamente como analgésicos, antiespasmódico, antieméticos y estimulantes del apetito. La toxicidad significativa del cannabis es poco común en los adultos, sin embargo, puede tener múltiples efectos adversos agudos y crónicos. La calidad de la evidencia en este campo se ha visto limitada por la corta duración de los estudios, los reducidos tamaños de las muestras, la falta de grupos de control y la existencia de sesgos en la mayoría de los estudios revisados. En este contexto, son necesarios más estudios de mejor calidad metodológica para apoyar el uso seguro de esta terapia en otras enfermedades. La decisión de incorporar los cannabinoides como terapia en alguna de las condiciones descritas depende de la evidencia, el uso de terapias previas y el tipo de paciente.

Controversial Link between Cannabis and Anticancer Treatments-Where Are We and Where Are We Going? A Systematic Review of the Literature

Simple Summary

In the field of oncology, preclinical research has shown that cannabis and cannabinoids modulate signaling pathways involved in cell proliferation, migration, invasion, angiogenesis, programmed cell death, and metastasis. Based on these findings, as medical cannabis becomes legal in more and more countries, cancer patients and their families are increasingly interested in the potential benefits of herbal medicine as an element of complementary and alternative medicine in their treatment. Although its clinical efficacy has been demonstrated in preclinical studies, clinical trials with cancer patients are lacking. To draw clear conclusions, we await the results of further prospective and randomized studies on this clinically relevant topic.

Abstract

Background and Objectives: Cannabinoids are currently used in cancer patients primarily for their pain-relieving and antiemetic properties. The aim of our review was to synthesize all available data of studies evaluating the therapeutic efficacy of cannabis in combination with oncological treatments in cancer patients and to explore ongoing studies with different goals and medical areas registered in the field of oncology worldwide. Materials and Methods: This study was performed in accordance with the PRISMA guidelines. A search using MEDLINE/PubMed database was performed between 1 January 2006 and 1 March 2022. Search terms included the following: cannabidiol, cannabis, CBD, dronabinol, endocannabinoids, medical marijuana, nabiximols, nabilone, THC, and cancer. All studies that examined the efficacy of cannabis administered during oncological treatments, regardless of cancer localization, subtype, and sample size, were considered eligible. Results: In three studies, cannabis was administered to patients with glioblastoma, and in two other studies, cannabis was used in combination with immunotherapy in various cancer subgroups. The results of the clinical trials in cancer patients are not sufficient to draw conclusions at this time. Interestingly, several other studies addressing the systemic effects of cannabinoids in cancer patients are currently listed in the U.S. National Library of Medicine’s registry on the ClinicalTrials.gov website. However, only one of the registered studies examined the efficacy of cannabinoids as a potential option for systemic cancer treatment. Conclusions: Although cannabis is touted to the public as a cancer cure, clinical trials need to clarify which combinations of chemotherapeutic agents with cannabinoids are useful for cancer patients.

Systematic reviews of randomized controlled trials of cannabinoid products in chronic pain conditions and for symptoms associated with multiple sclerosis: what do they tell us?

INTRODUCTION

: To investigate whether published systematic reviews of randomized controlled trials provide sufficient clarity to inform prescribing of cannabinoid products aimed for medicinal use, we examined their features and findings in two well-researched areas: chronic cancer/noncancer pain and multiple sclerosis (MS)-related symptoms.

AREAS COVERED

: Structured searches from January 2011 to 2 February 2021 identified 31 systematic reviews (with/without meta-analyses) that met the inclusion criteria. Support for the efficacy of cannabinoids was minimal in cancer pain, and somewhat stronger in noncancer (especially neuropathic) pain and MS spasticity. All systematic reviews and most meta-analyses grouped cannabinoid products together without appropriate consideration of their differential attributes (active constituent(s), concentration/strength, dosage forms, administration route), dosing regimens or treatment durations. Patient populations and efficacy outcome measures were inhomogeneous, particularly for studies in noncancer pain and MS. Separate results for specific cannabinoid formulations were rarely provided.

EXPERT OPINION

: The therapeutic effect of cannabinoids, as already demonstrated for some products, is not reflected clearly in the current range of systematic reviews and meta-analyses in chronic pain and MS. To truly inform evidence-based practice, future publications should aim to present results by individual product from well-conducted clinical trials using appropriate and homogeneous outcome measures in well-defined patient populations.

The Effectiveness and Safety of Medical Cannabis for Treating Cancer Related Symptoms in Oncology Patients

The use of medical cannabis (MC) to treat cancer-related symptoms is rising. However, there is a lack of long-term trials to assess the benefits and safety of MC treatment in this population. In this work, we followed up prospectively and longitudinally on the effectiveness and safety of MC treatment. Oncology patients reported on multiple symptoms before and after MC treatment initiation at one-, three-, and 6-month follow-ups. Oncologists reported on the patients' disease characteristics. Intention-to-treat models were used to assess changes in outcomes from baseline. MC treatment was initiated by 324 patients and 212, 158 and 126 reported at follow-ups. Most outcome measures improved significantly during MC treatment for most patients (p < 0.005). Specifically, at 6 months, total cancer symptoms burden declined from baseline by a median of 18%, from 122 (82-157) at baseline to 89 (45-138) at endpoint (-18.98; 95%CI= -26.95 to -11.00; p < 0.001). Reported adverse effects were common but mostly non-serious and remained stable during MC treatment. The results of this study suggest that MC treatment is generally safe for oncology patients and can potentially reduce the burden of associated symptoms with no serious MC-related adverse effects.

Treatment of Neuropathic Pain Directly Due to Cancer: An Update

Simple Summary

This review discusses treatment approaches for providing pain relief to oncological patients affected by pain caused by nerve damage due to the tumor, also known as neuropathic cancer pain. Although being encountered often and causing a relevant burden to these patients, neuropathic cancer pain remains still difficult to diagnose and treat. Strong evidence about the best drugs to be used remain limited, as do therapeutic choices.

Abstract

Neuropathic pain can be defined as pain related to abnormal somatosensory processing in either the peripheral or central nervous system. In this review article, with neuropathic cancer pain (NCP), we refer to pain due to nervous tissue lesions caused by the tumor or its metastases. Nervous tissue damage is the cause of cancer pain in approximately 40% of those experiencing cancer pain. Recognizing a neuropathic pathophysiology in these cases may be difficult and requires specific criteria that are not homogenously applied in clinical practice. The management of this type of pain can be challenging, requiring the use of specific non-opioid adjuvant drugs. The majority of the criteria for NCP diagnosis and management have been based mainly on results from the noncancer population, risking the failure of addressing the specific needs of this population of patients. In this review, we summarize current management options available for NCP and provide some insights on new promising treatments.

Does Cannabidiol Have a Benefit as a Supportive Care Drug in Cancer?

OPINION STATEMENT

Cannabinoids have been purported as having a wide range of therapeutic uses although currently, there is minimal evidence to support these claims. Patients with advanced cancer experience many distressing symptoms, with some turning to medicinal cannabis to help alleviate these. Focus has fallen on cannabidiol (CBD) as a potential treatment for a variety of symptoms in advanced cancer due to the lack of psychoactive side effects and the potential molecular mechanisms of action associated with this cannabinoid. Many cannabinoid products are easily available in the community, and more countries are legalizing or allowing over the counter products. Studies show that CBD is generally well tolerated, but there are many potential drug interactions that have not been well studied. Few studies have specifically looked at the role of CBD in treating cancer symptoms, with most focusing on combination cannabinoid products. There are currently many unknowns associated with CBD, including which symptoms it might be best for, appropriate dosing, and route of administration. This is especially important in advanced cancer where patients often have significant organ dysfunction and frailty that could impact on the pharmacology of CBD. A small pilot study has shown promise for a role of CBD in the psychological symptoms associated with advanced cancer. Further research is currently underway to further clarify the role of CBD in this setting and to understand how best it might help our patients. Currently we advocate that CBD be used in supervised clinical trials, so that efficacy and adverse effects can be closely monitored.

Mental Health Symptoms during the COVID-19 Pandemic among Cancer Survivors Who Endorse Cannabis: Results from the COVID-19 Cannabis Health Study

Our objective was to examine the prevalence of mental health symptoms and the behavioral impact of the COVID-19 pandemic on cancer survivors who endorse cannabis. Participants included 158 adults (≥18 years) who self-reported medicinal cannabis use and responded to our internet-based questionnaire (21 March 2020−24 March 2021). Data included 79 cancer survivors and 79 age-matched adults without a history of cancer. Descriptive statistics were used to compare demographics, the prevalence of generalized anxiety (GAD-7), depression (CES-D-10), and changes in behavior during the COVID-19 pandemic by cancer survivorship status. Overall, 60.8% and 48.1% of cancer survivors self-reported the use of cannabis to manage their anxiety and depression, respectively. Probable clinical depression (CES-D-10 score ≥ 10) and anxiety (GAD-7 score ≥ 10) were identified in 50.7% and 38.9% of cancer survivors, respectively. Cancer survivors were more likely to report that their anxiety symptoms made it very or extremely difficult to work, take care of home, or get along with others than their counterparts. Cancer survivors with anxiety and/or depression were more likely to fear giving COVID-19 to someone else (47.5% vs. 23.1%, p = 0.023) and to fear being diagnosed with COVID-19 (77.5% vs. 38.5%, p < 0.001) compared to cancer survivors without anxiety and depression symptoms. Further research is recommended to evaluate the use of cannabis as palliative care to improve mental health among cancer survivors.

Cannabis, Cannabinoids and Cannabis-Based Medicines in Cancer Care

As medical cannabis becomes legal in more states, cancer patients are increasingly interested in the potential utility of the ancient botanical in their treatment regimen. Although eager to discuss cannabis use with their oncologist, patients often find that their provider reports that they do not have adequate information to be helpful. Oncologists, so dependent on evidence-based data to guide their treatment plans, are dismayed by the lack of published literature on the benefits of medical cannabis. This results largely from the significant barriers that have existed to effectively thwart the ability to conduct trials investigating the potential therapeutic efficacy of the plant. This is a narrative review aimed at clinicians, summarizing cannabis phytochemistry, trials in the areas of nausea and vomiting, appetite, pain and anticancer activity, including assessment of case reports of antitumor use, with reflective assessments of the quality and quantity of evidence. Despite preclinical evidence and social media claims, the utility of cannabis, cannabinoids or cannabis-based medicines in the treatment of cancer remains to be convincingly demonstrated. With an acceptable safety profile, cannabis and its congeners may be useful in managing symptoms related to cancer or its treatment. Further clinical trials should be conducted to evaluate whether the preclinical antitumor effects translate into benefit for cancer patients. Oncologists should familiarize themselves with the available database to be able to better advise their patients on the potential uses of this complementary botanical therapy.

Efficacy and safety of therapeutic use of cannabis derivatives and their synthetic analogs: Overview of systematic reviews

The debate on the use of cannabinoids for therapeutic purposes is constantly on the rise. This overview aimed to map the evidence on the therapeutic effects of cannabis derivatives and their synthetic analogs. Systematic reviews (SRs) of randomized trials were identified through a comprehensive search in several databases, and their methodological quality were evaluated with AMSTAR-2. The results for main outcomes are presented, prioritizing those from updated and better quality SRs. Finally, 68 SRs, addressing 37 different health conditions, were included. The methodological quality was high for eight SRs. The evidence certainty (GRADE) for the effects of cannabinoids is not high for any of the outcomes identified. Evidence certainty was moderate for the following: (a) cannabidiol appears to be beneficial for quality of life but increases the risk of adverse events in ulcerative colitis; (b) cannabinoids in general appear to have no clinically important benefit for chronic non-oncologic pain, spasticity-related pain in multiple sclerosis, or for acute post-operative pain; (c) cannabinoids in general appear to have a benefit in reducing chemotherapy-related nausea and vomiting. For all other outcomes from remaining comparisons, the evidence certainty was low, very low, or not evaluated, which prevents recommendations for or against their routine use.

Cannabis and the Cancer Patient

Session 2 of the National Cancer Institute's Cannabis, Cannabinoids, and Cancer Research Workshop opened with testimony from a lymphoma survivor who detailed medicinal cannabis-related improvements in nausea, low appetite, insomnia, and mental health and the limited clinical counsel she received regarding cannabis use. Discussion next turned to the evolution of the legal landscape of cannabis in the United States, one in which state and federal laws frequently conflict and the Controlled Substance Act renders cannabis Schedule I. This legal climate creates conundrums for US medicinal cannabis researchers who contend with limited funding opportunities, avenues to source trial drug, and procedural red tape and for oncology clinicians who recommend medicinal cannabis to patients with some frequency while perceiving themselves as ill equipped to make such clinical recommendations. Ultimately, it creates challenges for cancer patients who find themselves turning to nonmedical and anecdotal information sources. The risks of cannabis use by the cancer patient were discussed next. These include infection, pharmacodynamic and pharmacokinetic drug-botanical interactions, cyclic nausea and vomiting, e-cigarette or vaping product use-associated illness, legal issues, and high cost. The session concluded with a broad survey of the research supporting oncologic cannabinoid use, conclusive evidence for chemotherapy-induced nausea and vomiting, and suggestive evidence for cancer-related pain.

Medical Cannabis as Adjunctive Therapy for Head and Neck Cancer Patients

The goal of this systematic review was to define a consensus within the current literature regarding the impact/effect of cannabis or cannabinoids on the treatment of patients with head and neck cancer. We conducted a review of PubMed, Embase, and Web of Science databases, using a comprehensive search strategy, focusing on articles relating to head & neck cancer and cannabis/cannabinoids without a time limit for publication.

Two, independent reviewers screened articles based on title/abstract and included the ones selected by both. We then conducted a full-text review and excluded all articles which did not meet inclusion criteria. A single reviewer then assessed studies for methodological quality and extracted relevant data using a premade data collection tool. We identified five studies that met inclusion criteria. Studies were of varying quality and the majority investigated recreational cannabis use with only one study reporting dosing across participants. Lack of standardized cannabis exposure presents a wide array of potential confounding variables across the remaining studies. Meta-analysis was not attempted due to variability in reported outcomes.

It is impossible to draw any conclusions regarding the benefit or adverse effects of current medical cannabis products in this patient population. The literature regarding the effect of cannabis/cannabinoids on head & neck cancer patients is limited. However, the current lack of evidence does not definitively disprove the efficacy of cannabis. High-quality studies are necessary for physicians to provide advice to patients who are either using or interested in cannabis as an adjunctive treatment.

Cannabinoid Formulations and Delivery Systems: Current and Future Options to Treat Pain

The field of Cannabis sativa L. research for medical purposes has been rapidly advancing in recent decades and a growing body of evidence suggests that phytocannabinoids are beneficial for a range of conditions. At the same time impressing development has been observed for formulations and delivery systems expanding the potential use of cannabinoids as an effective medical therapy. The objective of this review is to present the most recent results from pharmaceutical companies and research groups investigating methods to improve cannabinoid bioavailability and to clearly establish its therapeutic efficacy, dose ranges, safety and also improve the patient compliance. Particular focus is the application of cannabinoids in pain treatment, describing the principal cannabinoids employed, the most promising delivery systems for each administration routes and updating the clinical evaluations. To offer the reader a wider view, this review discusses the formulation starting from galenic preparation up to nanotechnology approaches, showing advantages, limits, requirements needed. Furthermore, the most recent clinical data and meta-analysis for cannabinoids used in different pain management are summarized, evaluating their real effectiveness, in order also to spare opioids and improve patients' quality of life. Promising evidence for pain treatments and for other important pathologies are also reviewed as likely future directions for cannabinoids formulations.

Management of Myeloma Manifestations and Complications: The Cornerstone of Supportive Care: Recommendation of the Canadian Myeloma Research Group (formerly Myeloma Canada Research Network) Consensus Guideline Consortium

Multiple myeloma (MM) is a hematological cancer associated with significant symptomatic burden. Bone disease, renal insufficiency, cytopenias, infection, and peripheral neuropathy, among other disease manifestations and complications, impair patients' quality of life. The Canadian Myeloma Research Group Consensus Guideline Consortium, formerly Myeloma Canada Research Network Consensus Guideline Consortium, proposes national consensus recommendations for the management of MM-related manifestations and complications. To address the needs of Canadian physicians and people living with MM across the country, this document focuses on the improvement and maintenance of patient care by clarifying best-practice approaches for the prevention, detection and management of disease manifestations and complications. The Canadian Myeloma Research Group Consensus Guideline Consortium will periodically review the recommendations herein and update as necessary.