A user's guide to cannabinoid therapies in oncology

Targeting TRPV4 Channels for Cancer Pain Relief

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

Should oncologists trust cannabinoids?

Cannabis enjoyed a "golden age" as a medicinal product in the late 19th, early 20th century, but the increased risk of overdose and abuse led to its criminalization. However, the 21st century have witnessed a resurgence of interest and a large body of literature regarding the benefits of cannabinoids have emerged. As legalization and decriminalization have spread around the world, cancer patients are increasingly interested in the potential utility of cannabinoids. Although eager to discuss cannabis use with their oncologist, patients often find them to be reluctant, mainly because clinicians are still not convinced by the existing evidence-based data to guide their treatment plans. Physicians should prescribe cannabis only if a careful explanation can be provided and follow up response evaluation ensured, making it mandatory for them to be up to date with the positive and also negative aspects of the cannabis in the case of cancer patients. Consequently, this article aims to bring some clarifications to clinicians regarding the sometimes-confusing various nomenclature under which this plant is mentioned, current legislation and the existing evidence (both preclinical and clinical) for the utility of cannabinoids in cancer patients, for either palliation of the associated symptoms or even the potential antitumor effects that cannabinoids may have.

A Cross Talk between the Endocannabinoid System and Different Systems Involved in the Pathogenesis of Hypertensive Retinopathy

The prognosis of hypertension leads to organ damage by causing nephropathy, stroke, retinopathy, and cardiomegaly. Retinopathy and blood pressure have been extensively discussed in relation to catecholamines of the autonomic nervous system (ANS) and angiotensin II of the renin–angiotensin aldosterone system (RAAS) but very little research has been conducted on the role of the ECS in the regulation of retinopathy and blood pressure. The endocannabinoid system (ECS) is a unique system in the body that can be considered as a master regulator of body functions. It encompasses the endogenous production of its cannabinoids, its degrading enzymes, and functional receptors which innervate and perform various functions in different organs of the body. Hypertensive retinopathy pathologies arise normally due to oxidative stress, ischemia, endothelium dysfunction, inflammation, and an activated renin–angiotensin system (RAS) and catecholamine which are vasoconstrictors in their biological nature. The question arises of which system or agent counterbalances the vasoconstrictors effect of noradrenaline and angiotensin II (Ang II) in normal individuals? In this review article, we discuss the role of the ECS and its contribution to the pathogenesis of hypertensive retinopathy. This review article will also examine the involvement of the RAS and the ANS in the pathogenesis of hypertensive retinopathy and the crosstalk between these three systems in hypertensive retinopathy. This review will also explain that the ECS, which is a vasodilator in its action, either independently counteracts the effect produced with the vasoconstriction of the ANS and Ang II or blocks some of the common pathways shared by the ECS, ANS, and Ang II in the regulation of eye functions and blood pressure. This article concludes that persistent control of blood pressure and normal functions of the eye are maintained either by decreasing systemic catecholamine, ang II, or by upregulation of the ECS which results in the regression of retinopathy induced by hypertension.

Cannabidiol in canine epilepsy

The anticonvulsant effect of cannabidiol (CBD), which has been confirmed by findings from animal models and human trials, has attracted the interest of veterinary practitioners and dog owners. Moreover, social media and public pressure has sparked a renewed awareness of cannabinoids, which have been used for epilepsy since ancient times. Unfortunately, at this moment veterinarians and veterinary neurologists have difficulty prescribing cannabinoids because of the paucity of sound scientific studies. Pharmacokinetic studies in dogs have demonstrated a low oral bioavailability of CBD and a high first-pass effect through the liver. Administering CBD in oil-based formulations and/or with food has been shown to enhance the bioavailability in dogs, rats and humans. Tolerability studies in healthy dogs and dogs with epilepsy have demonstrated that CBD was safe and well tolerated with only mild to moderate adverse effects. In this context, it should be noted that the quality of available CBD varies widely, underscoring the importance of pharmaceutical quality and its control. One clinical trial in dogs with drug-resistant idiopathic epilepsy failed to confirm a difference in response rates between the CBD group and the placebo group, while in another cross-over trial a ≥ 50 % reduction in epileptic seizure frequency was found in six of 14 dogs in the treatment phase, a reduction that was not observed during the placebo phase. Based on the current state of knowledge it is not possible to provide clear-cut recommendations for the use of CBD in canine epilepsy. Randomized controlled canine trials with large sample sizes are needed to determine the range of therapeutic plasma concentrations, develop evidence-based dosing regimens, determine the efficacy of cannabidiol in drug-refractory epilepsy, and explore potential associations between treatment effects and different etiologies, epilepsy types, and drug combinations.

Routes of administration, reasons for use, and approved indications of medical cannabis in oncology: a scoping review

INTRODUCTION

Some patients diagnosed with cancer use medical cannabis to self-manage undesirable symptoms, including nausea and pain. To improve patient safety and oncological care quality, the routes of administration for use of medical cannabis, patients' reasons, and prescribed indications must be better understood.

METHODS

Based on the Joanna Briggs Institute guidelines, a scoping review was conducted to map the current evidence regarding the use of medical cannabis in oncological settings based on the experiences of patients diagnosed with cancer and their healthcare providers. A search strategy was developed with a scientific librarian which included five databases (CINAHL, Web of Science, Medline, Embase, and PsycINFO) and two grey literature sources (Google Scholar and ProQuest). The inclusion criteria were: 1) population: adults aged 18 and over diagnosed with cancer; 2) phenomena of interest: reasons for cannabis use and/or the prescribed indications for medical cannabis; 3) context: oncological setting. French- or English-language primary empirical studies, knowledge syntheses, and grey literature published between 2000 and 2021 were included. Data were extracted by two independent reviewers and subjected to a thematic analysis. A narrative description approach was used to synthesize and present the findings.

RESULTS

We identified 5,283 publications, of which 163 met the eligibility criteria. Two main reasons for medical cannabis use emerged from the thematic analysis: limiting the impacts of cancer and its side effects; and staying connected to others. Our results also indicated that medical cannabis is mostly used for three approved indications: to manage refractory nausea and vomiting, to complement pain management, and to improve appetite and food intake. We highlighted 11 routes of administration for medical cannabis, with oils and oral solutions the most frequently reported.

CONCLUSION

Future studies should consider the multiple routes of administration for medical cannabis, such as inhalation and edibles. Our review highlights that learning opportunities would support the development of healthcare providers' knowledge and skills in assessing the needs and preferences of patients diagnosed with cancer who use medical cannabis.

Medical Cannabis in Pediatric Oncology: Friend or Foe?

The antineoplastic effects of cannabis have been known since 1975. Since the identification of the components of the endogenous cannabinoid system (ECS) in the 1990s, research into the potential of cannabinoids as medicine has exploded, including in anti-cancer research. However, nearly all of this research has been on adults. Physicians and governing bodies remain cautious in recommending the use of cannabis in children, since the ECS develops early in life and data about cannabis exposure in utero show negative outcomes. However, there exist many published cases of use of cannabis in children to treat pediatric epilepsy and chemotherapy-induced nausea and vomiting (CINV) that show both the safety and efficacy of cannabis in pediatric populations. Additionally, promising preclinical evidence showing that cannabis has anti-cancer effects on pediatric cancer warrants further investigation of cannabis' use in pediatric cancer patients, as well as other populations of pediatric patients. This review aims to examine the evidence regarding the potential clinical utility of cannabis as an anti-cancer treatment in children by summarizing what is currently known about uses of medical cannabis in children, particularly regarding its anti-cancer potential.

Chronic Administration of Cannabinoid Receptor 2 Agonist (JWH-133) Increases Ectopic Ovarian Tumor Growth and Endocannabinoids (Anandamide and 2-Arachidonoyl Glycerol) Levels in Immunocompromised SCID Female Mice

Cannabinoid-based therapies are increasingly being used by cancer patients to treat chemotherapy-induced nausea and vomiting. Recently, cannabinoids have gained increased attention for their effects on cancer growth. Indeed, the effect of CB₂ (JWH-015, JWH-133) agonists on breast cancer models have shown to reduce the size of breast cancer tumors. However, these studies assessing breast cancer progression were using CB₂ agonist administered early into the cancer progression therefore assessing their effects on already established tumors is a critical need. In our study, we evaluate tumor growth using an ectopic xenograft ovarian (SKOV-3 and OVCAR-5) cancer model. The impact of chronic (30 days) administration of CB₂ (JWH-133) agonist will be evaluated and started on 30 days of ectopic ovarian tumors. We will then evaluate and determine the mechanisms involved in ovarian cancer tumor growth by measuring levels of anandamide and 2-arachidonoyl glycerol as well as protein levels of CB₁, CB₂, ERα, ERβ, GPER, TNFα, IL-1β and IL-6 in ovarian and tumor tissues. Our results demonstrate a significant increase in ectopic ovarian tumor growth following chronic administration of JWH-133. Ovarian cancer tumor tissues chronically (30 days) treated with JWH-133 in comparison to vehicle treated groups showed an increase in endocannabinoid (AEA and 2-AG) and protein (CB₂ and TNFα) levels with a decrease in GPER protein levels. Interestingly, our study emphasizes the importance of studying the impact of cannabinoid compounds on already established tumors to improve our understanding of cannabinoid-based therapies and, therefore better address clinical needs in cancer patients.

Cannabis-Based Oral Emulsion for Medical Purposes to Meet the Needs of Patients: Formulation, Quality and Stability

Current Italian legislation provides that medical Cannabis can be administered orally as an extract if it has been titrated to determine the concentration of active molecules. In this context, there is a need to provide known and adequate quantities of active ingredients in order to guarantee uniform therapies that lead to the optimization of risks/benefits. This is fundamental considering that the limited availability on the market of registered Cannabis-based products for medical use means that prescribed therapies are usually prepared as galenic preparations. Consequently, the preparation procedures must be consistent with the instrumentation usually present in the laboratories of community pharmacies. In this context, the purpose of this work was to standardize the preparation procedure for oil-in-water (O/W) emulsions to exploit advantages in terms of ease of administration and dosage adjustment, but also to ensure the palatable organoleptic characteristics of the finished product. For the formulations being studied, in addition to the quality according to the directives set out in the European Pharmacopoeia, the stability was evaluated to assure adequate validity for therapeutic uses.

Cannabinoids and Endocannabinoid System Changes in Intestinal Inflammation and Colorectal Cancer

Despite the multiple preventive measures and treatment options, colorectal cancer holds a significant place in the world's disease and mortality rates. The development of novel therapy is in critical need, and based on recent experimental data, cannabinoids could become excellent candidates. This review covered known experimental studies regarding the effects of cannabinoids on intestinal inflammation and colorectal cancer. In our opinion, because colorectal cancer is a heterogeneous disease with different genomic landscapes, the choice of cannabinoids for tumor prevention and treatment depends on the type of the disease, its etiology, driver mutations, and the expression levels of cannabinoid receptors. In this review, we describe the molecular changes of the endocannabinoid system in the pathologies of the large intestine, focusing on inflammation and cancer.

The Effectiveness of Cannabis and Cannabis Derivatives in Treating Lower Back Pain in the Aged Population: A Systematic Review

BACKGROUND/AIMS

Cannabis is increasingly used in the management of pain, though minimal research exists to support its use since approval. Reduction in stigma has led to a growing interest in pharmaceutical cannabinoids as a possible treatment for lower back pain (LBP). The objective of this review was to assess the role and efficacy of cannabis and its derivatives in the management of LBP and compile global data related to the role of cannabis in the management of LBP in an aging population.

METHODS

A systematic review was conducted using predetermined keywords by 3 independent researchers. Predetermined inclusion and exclusion criteria were applied, and 23 articles were selected for further analysis.

RESULTS

Studies identified both significant and insignificant impacts of cannabis on LBP. Contradicting evidence was noted on the role of cannabis in the management of anxiety and insomnia, 2 common comorbidities with LBP. The existing literature suggests that cannabis may be used in the management of LBP and comorbid symptoms.

CONCLUSIONS

Further research is needed to consider cannabis as an independent management option. There is a lack of evidence pertaining to the benefits of cannabis in an aged population, and thus, additional research is warranted to support its use in the aged population.

Therapeutic Potential of Cannabidiol, Cannabidiolic Acid, and Cannabidiolic Acid Methyl Ester as Treatments for Nausea and Vomiting

Introduction: Nausea and vomiting are the most distressing symptoms reported by oncology patients undergoing anticancer treatment. With the currently available treatments, vomiting and especially nausea remain problematic, highlighting the need for alternative treatments. Discussion: Here we review in vitro and in vivo evidence for the effectiveness of the nonpsychoactive cannabinoid cannabidiol (CBD) in managing nausea and vomiting. In addition, we also review the evidence for CBD's acidic precursor, cannabidiolic acid (CBDA), and a methylated version of CBDA (CBDA-ME) in these phenomena. Finally, we explore the potential role of CBD in the treatment of cannabinoid hyperemesis syndrome. Conclusions: CBD has demonstrated efficacy in reducing nausea and vomiting, with CBDA and CBDA-ME being more potent. The data suggest a need for these compounds to be evaluated in clinical trials for their ability to reduce nausea and/or vomiting.

A randomized trial of medical cannabis in patients with stage IV cancers to assess feasibility, dose requirements, impact on pain and opioid use, safety, and overall patient satisfaction

PURPOSE

The prevalence of medical cannabis (MC) use in patients with cancer is growing, but questions about safety, efficacy, and dosing remain. Conducting randomized, controlled trials (RCTs) using state-sponsored MC programs is novel and could provide data needed to guide patients and providers.

METHODS

A pilot RCT of patients with stage IV cancer requiring opioids was conducted. Thirty patients were randomized 1:1 to early cannabis (EC, n = 15) versus delayed start cannabis (DC, n = 15). The EC group obtained 3 months (3 M) of MC through a state program at no charge, while the DC group received standard oncology care without MC for the first 3 M. Patients met with licensed pharmacists at one of two MC dispensaries to determine a suggested MC dosing, formulation, and route. Patients completed surveys on pain levels, opioid/MC use, side effects, and overall satisfaction with the study.

RESULTS

Interest in the study was high as 36% of patients who met eligibility criteria ultimately enrolled. The estimated mean daily THC and CBD allotments at 3 M were 34 mg and 17 mg, respectively. A higher proportion of EC patients achieved a reduction in opioid use and improved pain control. No serious safety issues were reported, and patients reported high satisfaction.

CONCLUSION

Conducting RCTs using a state cannabis program is feasible. The addition of MC to standard oncology care was well-tolerated and may lead to improved pain control and lower opioid requirements. Conducting larger RCTs with MC in state-sponsored programs may guide oncology providers on how to safely and effectively incorporate MC for interested patients.

TRP channels in cancer pain

Chronic pain is a common symptom experienced during cancer progression. Additionally, some patients experience bone pain caused by cancer metastasis, which further complicates the prognosis. Cancer pain is often treated using opioid-based pharmacotherapy, but these drugs possess several adverse effects. Accordingly, new mechanisms for cancer pain management are being explored, including transient receptor potential channels (TRPs). TRP ion channels are expressed in several tissues and play a key role in pain detection, especially TRP vanilloid 1 (TRPV1) and TRP ankyrin 1 (TRPA1). In the present review, we describe the role of TRPV1 and TRPA1 involved in cancer pain mechanisms. Several studies have revealed that the administration of TRPV1 or TRPA1 agonists/antagonists and TRPV1 or TRPA1 knockdown reduced sensitivity to nociception in cancer pain models. TRPV1 was also found to be involved in various models of cancer-induced bone pain (CIBP), with TRPV1 expression reportedly enhanced in some models. These studies have demonstrated the TRPV1 or TRPA1 association with cancer pain in models induced by tumour cell inoculation into the bone cavity, hind paw, mammary fat pad, and sciatic nerve in mice or rats. To date, only resiniferatoxin, a TRPV1 agonist, has been evaluated in clinical trials for cancer pain and showed preliminary positive results. Thus, TRP channels are potential targets for managing cancer-related pain syndromes.

Cannabis-Based Oral Formulations for Medical Purposes: Preparation, Quality and Stability

Current legislation in Italy provides that medical Cannabis may be administered orally or by inhalation. One of the fundamental criteria for the administration of oral formulations is that they deliver a known consistent quantity of the active ingredients to ensure uniform therapies leading to the optimisation of the risks/benefits. In 2018, our group developed an improved Cannabis oil extraction technique. The objective of the present work was to carry out a stability study for the oil extracts obtained by this method. Furthermore, in order to facilitate the consumption of the prescribed medical Cannabis therapy by patients, a standard procedure was defined for the preparation of a single-dose preparation for oral use (hard capsules) containing the oil extract; thereafter, the quality and stability were evaluated. The hard capsules loaded with the oil extract were analysed and found to be uniform in content. The encapsulation process did not alter the quantity of the active molecule present in the oil. The stability tests yielded excellent results. Since the capsule dosage form is easily transported and administered, has pleasant organoleptic properties and is stable at room temperature for extended periods of time, this would facilitate the adherence to therapy by patients in treatment.

"Less pain with more gain"-Managing wound-related pain with cannabis-based medicines

Wound-related pain poses a serious challenge for patients and physicians. It is a complex pathophysiologic construct that may be stratified, from the patient's perspective, into baseline pain and breakthrough pain. The current paradigm for treating wound related pain involves the overuse of opioids and other co-analgesics with little regard for breakthrough pain. These standard medications have a propensity for deleterious side effects while some of them inhibit wound healing, effectively perpetuating the wound and the related pain. In particular, the overuse of opioids is a contributor to the global opioid crisis. It is evident that a new paradigm needs to be considered. Cannabis-based medicines are a prominent prospect under investigation for their potential to reduce dosages of status quo analgesics while effectively reducing pain. The authors propose a new paradigm that emphasizes the use of Cannabis-Based Medicines, delivered through multiple routes, while recommending the need for more foundational scientific investigation into mechanisms, and clinical controlled trials to determine optimal combinations, dosages, and protocols.

Cannabis sativa L. as a Natural Drug Meeting the Criteria of a Multitarget Approach to Treatment

Cannabis sativa L. turned out to be a valuable source of chemical compounds of various structures, showing pharmacological activity. The most important groups of compounds include phytocannabinoids and terpenes. The pharmacological activity of Cannabis (in epilepsy, sclerosis multiplex (SM), vomiting and nausea, pain, appetite loss, inflammatory bowel diseases (IBDs), Parkinson's disease, Tourette's syndrome, schizophrenia, glaucoma, and coronavirus disease 2019 (COVID-19)), which has been proven so far, results from the affinity of these compounds predominantly for the receptors of the endocannabinoid system (the cannabinoid receptor type 1 (CB1), type two (CB2), and the G protein-coupled receptor 55 (GPR55)) but, also, for peroxisome proliferator-activated receptor (PPAR), glycine receptors, serotonin receptors (5-HT), transient receptor potential channels (TRP), and GPR, opioid receptors. The synergism of action of phytochemicals present in Cannabis sp. raw material is also expressed in their increased bioavailability and penetration through the blood-brain barrier. This review provides an overview of phytochemistry and pharmacology of compounds present in Cannabis extracts in the context of the current knowledge about their synergistic actions and the implications of clinical use in the treatment of selected diseases.

The impact of legalization of access to recreational Cannabis on Canadian medical users with Cancer

Background

Canada legalized cannabis use for medical purposes in 1999. Legalization of cannabis for recreational purposes in October 2018 offered the opportunity to assess the impact of recreational legalization on cancer patients’ patterns of use to identify learning points that could be helpful to other countries considering similar legislation.

Method

Two identical anonymous cross-sectional surveys were administered to cancer patients in British Columbia 2 months before and 3 months following legalization, with the same eligibility criteria.

The prevalence of medical cannabis use, the distribution of symptoms leading to use, the most common types of cannabis products and sources, reasons for stopping using cannabis, and barriers to access were assessed.

Results

The overall response rate was 27%. Both cohorts were similar regarding age (median = 66 yrs), gender (53% female), and education (approximately 85% of participants had an education level of high school graduation and higher). Respondents had multiple motives for taking cannabis, including to manage multiple symptoms, to treat cancer, and for recreational reasons. The majority of patients in both surveys did not use the legal medical access system.

Comparison of the two cohorts showed that after legalization the prevalence of current cannabis use increased by 26% (23·1% to 29·1%, p-value 0·01), including an increased disclosure of recreational motive for use, from 32 to 40%. However, in the post-legalization cohort more Current Users reported problems getting cannabis (18%) than the pre-legalization cohort (8%), (p-value < 0·01). The most common barrier cited was lack of available preferred products, including edibles, as these were only available from illegal dispensaries.

Conclusions

Results showed that legalization of cannabis for recreational purposes may have an impact on those who use medical cannabis. Impacts include an increase in prevalence of use; problems accessing preferred products legally; higher cost, and difficulties using a legal access system. The desired goal of regulation in reducing harms from use of illegal cannabis products are unlikely to be achieved if the legal process is less attractive to patients than use of illegal sources.

Impact of Recreational and Medicinal Cannabinoids on Quality of Life and Occupation: A Scoping Review

IMPORTANCE

Cannabinoids are at the center of much interest and controversy within health care and society. However, minimal research has investigated the impact of cannabinoids on quality of life (QoL) and occupation.

OBJECTIVE

The literature suggests that cannabinoids may have therapeutic potential, although the available research is limited. A scoping review was conducted to address the gap in the literature regarding the impact of recreational and medicinal cannabinoids on QoL and occupational engagement.

DATA SOURCES

Databases searched included Ovid and CINAHL; sources derived from a manual search of reference lists were also used. Of the 691 articles that were identified, 22 articles met the inclusion and exclusion criteria.

STUDY SELECTION AND DATA COLLECTION

This scoping review was conducted in accordance with Arksey and O'Malley's five stages. Inclusion criteria included English language, clear focus or description on the impact of nonsynthetic cannabinoids on QoL and occupation, and published between January 2011 and May 2019. Exclusion criteria included minors, single case studies, animal studies, antineoplastic articles, and articles that only discussed or investigated effects of synthetic cannabinoids.

FINDINGS

The findings were inconclusive, and the primary research that emerged from the literature investigated the effects of cannabinoids on pain management, sleep, appetite, and other physiological functions in both recreational and medicinal users.

CONCLUSIONS AND RELEVANCE

The findings derived from the literature raised more questions, and further research is warranted. Occupational therapy practitioners have an opportunity to use their knowledge and skills to address the impact of cannabinoids on occupational engagement and QoL.

WHAT THIS ARTICLE ADDS

Practitioners have the opportunity to provide education regarding cannabis use and monitor how it affects occupational engagement and QoL for both recreational and medicinal users.

Herbal Preparations of Medical Cannabis: A Vademecum for Prescribing Doctors

Cannabis has been used for centuries for therapeutic purposes. In the last century, the plant was demonized due to its high abuse liability and supposedly insufficient health benefits. However, recent decriminalization policies and new scientific evidence have increased the interest in cannabis therapeutic potential of cannabis and paved the way for the release of marketing authorizations for cannabis-based products. Although several synthetic and standardized products are currently available on the market, patients’ preferences lean towards herbal preparations, because they are easy to handle and self-administer. A literature search was conducted on multidisciplinary research databases and international agencies or institutional websites. Despite the growing popularity of medical cannabis, little data is available on the chemical composition and preparation methods of medical cannabis extracts. The authors hereby report the most common cannabis preparations, presenting their medical indications, routes of administration and recommended dosages. A practical and helpful guide for prescribing doctors is provided, including suggested posology, titration strategies and cannabinoid amounts in herbal preparations obtained from different sources of medical cannabis.

The Effectiveness of Topical Cannabidiol Oil in Symptomatic Relief of Peripheral Neuropathy of the Lower Extremities

Background:

Peripheral neuropathy can significantly impact the quality of life for those who are affected, as therapies from the current treatment algorithm often fail to deliver adequate symptom relief. There has, however, been an increasing body of evidence for the use of cannabinoids in the treatment of chronic, noncancer pain. The efficacy of a topically delivered cannabidiol (CBD) oil in the management of neuropathic pain was examined in this four-week, randomized and placebocontrolled trial.

Methods:

In total, 29 patients with symptomatic peripheral neuropathy were recruited and enrolled. 15 patients were randomized to the CBD group with the treatment product containing 250 mg CBD/3 fl. oz, and 14 patients were randomized to the placebo group. After four weeks, the placebo group was allowed to crossover into the treatment group. The Neuropathic Pain Scale (NPS) was administered biweekly to assess the mean change from baseline to the end of the treatment period.

Results:

The study population included 62.1% males and 37.9% females with a mean age of 68 years. There was a statistically significant reduction in intense pain, sharp pain, cold and itchy sensations in the CBD group when compared to the placebo group. No adverse events were reported in this study.

Conclusions:

Our findings demonstrate that the transdermal application of CBD oil can achieve significant improvement in pain and other disturbing sensations in patients with peripheral neuropathy. The treatment product was well tolerated and may provide a more effective alternative compared to other current therapies in the treatment of peripheral neuropathy.

Pharmacists and the future of cannabis medicine

OBJECTIVES

To summarize the history and evolution of cannabis use and policies and to review current therapeutic uses, safety, and the central role pharmacists can play.

SUMMARY

Cannabis regulation and use have evolved over the centuries and are becoming more widely accepted, with over two-thirds of states in the United States having an approved cannabis program. However, changing policy and a paucity of controlled clinical trials has led to questions on the safety and effectiveness of cannabinoid therapies. Although there are conditions for which cannabinoids may be helpful, potential contraindications, adverse effects, and drug-drug interactions should be taken into account.

CONCLUSION

Pharmacists are in a unique position based on their accessibility, knowledge, and skills to guide product selection, dosing, and discuss drug interactions and adverse effects to educate patients on safe cannabis use, whether it be delta-9-tetrahydrocannabinol, cannabidiol, or a combination thereof. Pharmacists and pharmacy organizations, moreover, should advocate for an integral role in the medical cannabis movement to ensure patient safety and evaluate cannabinoid pharmacology, pharmacokinetics, drug-drug interactions, safety, and efficacy through rigorous investigations.

Terpenoids and Phytocannabinoids Co-Produced in Cannabis Sativa Strains Show Specific Interaction for Cell Cytotoxic Activity

Mixtures of different Cannabis sativa phytocannabinoids are more active biologically than single phytocannabinoids. However, cannabis terpenoids as potential instigators of phytocannabinoid activity have not yet been explored in detail. Terpenoid groups were statistically co-related to certain cannabis strains rich in Δ9-tetrahydrocannabinolic acid (THCA) or cannabidiolic acid (CBDA), and their ability to enhance the activity of decarboxylase phytocannabinoids (i.e., THC or CBD) was determined. Analytical HPLC and GC/MS were used to identify and quantify the secondary metabolites in 17 strains of C. sativa, and correlations between cannabinoids and terpenoids in each strain were determined. Column separation was used to separate and collect the compounds, and cell viability assay was used to assess biological activity. We found that in "high THC" or "high CBD" strains, phytocannabinoids are produced alongside certain sets of terpenoids. Only co-related terpenoids enhanced the cytotoxic activity of phytocannabinoids on MDA-MB-231 and HCT-116 cell lines. This was found to be most effective in natural ratios found in extracts of cannabis inflorescence. The correlation in a particular strain between THCA or CBDA and a certain set of terpenoids, and the partial specificity in interaction may have influenced the cultivation of cannabis and may have implications for therapeutic treatments.

Medical Cannabis Use in Glioma Patients Treated at a Comprehensive Cancer Center in Florida

Background: Glioma is a devastating primary tumor of the central nervous system with difficult-to-manage symptoms. Cannabis products have been postulated to potentially benefit glioma patients. Recent state legalization allowed investigators an opportunity to study glioma patients' adoption of medical marijuana (MM). Objective: Our goals were to: (1) determine the prevalence of marijuana use, both through physician recommendation and self-medication, and (2) evaluate its perceived risks and benefits in glioma patients. Design: Self-report data were collected and descriptive analyses were conducted. Setting/Subjects: Participants were adult, English-speaking patients undergoing treatment for primary non-recurrent malignant glioma in neuro-oncology clinics at an NCI-designated Comprehensive Cancer Center. Measurements: The survey on MM was adapted from previous research and included questions on knowledge and attitudes toward MM; use, frequency, type, and sourcing of MM; and reasons for use of MM and perceived symptom relief among users. Results: A total of 73 patients were surveyed. The majority of participants were aware that MM was legal in the state, and most reported learning of this through the media. Over 70% of participants reported having considered using MM, and a third reported using marijuana products after their diagnosis. Most received recommendations from friends/family rather than a medical provider, and only half of the users had obtained a physician's recommendation. Users generally reported benefits. Conclusions: With the increasing national conversation that accompanies legalization, glioma patients are pursuing marijuana for the treatment for their symptoms. More research and education is needed to bring health care providers into the conversation.

Patterns of Medical Cannabis Use among Cancer Patients from a Medical Cannabis Dispensary in New York State

Background: Research on the patterns of use of medical cannabis among cancer patients is lacking. Objective: To describe patterns of medical cannabis use by patients with cancer, and how patterns differ from patients without cancer. Design/Measurements: We performed secondary data analysis using data from a medical cannabis licensee in New York State, analyzing demographic information, qualifying conditions, and symptoms, and the medical cannabis product used, including tetrahydrocannabinol (THC) to cannabidiol (CBD) ratios. Setting/Subjects: Adults age ≥18 who used New York State medical cannabis licensee products between January 2016 and December 2017. Results: There were a total of 11,590 individuals with 1990 (17.2%) having cancer who used at least one cannabis product. Patients with cancer using cannabis were older and more likely to be female. The most common qualifying symptom for both cancer and noncancer patients was severe or chronic pain. Cancer patients were more likely to use the sublingual tincture form of cannabis (n = 1098, 55.2%), while noncancer patients were more likely to use the vaporization form (n = 4222, 44.0%). Over time, across all patients, there was an increase in the THC daily dose by a factor of 0.20 mg/week, yielding a corresponding increase in the THC:CBD daily ratio. Compared with noncancer patients, these trends were not different in the cancer group for THC daily dose, but there were less pronounced increases in the THC:CBD daily ratio over time among cancer patients. Conclusions: Our study found some key differences in demographics and medical cannabis product use between patients with cancer and without cancer.

Reduced Tolerance and Asymmetrical Crosstolerance to Effects of the Indole Quinuclidinone Analog PNR-4-20, a G Protein-Biased Cannabinoid 1 Receptor Agonist in Mice: Comparisons with Δ9-Tetrahydrocannabinol and JWH-018

Most cannabinoid 1 receptor (CB₁R) agonists will signal through both G protein-dependent and -independent pathways in an unbiased manner. Recruitment of β-arrestin 2 desensitizes and internalizes receptors, producing tolerance that limits therapeutic utility of cannabinoids for chronic conditions. We developed the indole quinuclidinone (IQD) analog (Z)-2-((1-(4-fluorobenzyl)-1H-indol-3-yl)methylene)quinuclidin-3-one (PNR-4-20) as a novel G protein-biased agonist at CB₁Rs, and the present studies determine if repeated administration of PNR-4-20 produces lesser tolerance to in vivo effects compared with unbiased CB₁R agonists Δ⁹-tetrahydrocannabinol (Δ⁹-THC) and 1-pentyl-3-(1-naphthoyl)indole (JWH-018). Adult male National Institutes of Health Swiss mice were administered comparable doses of PNR-4-20 (100 mg/kg), Δ⁹-THC (30 mg/kg), or JWH-018 (3 mg/kg) once per day for five consecutive days to determine tolerance development to hypothermic, antinociceptive, and cataleptic effects. Persistence of tolerance was then determined after a drug abstinence period. We found that unbiased CB₁R agonists Δ⁹-THC and JWH-018 produced similar tolerance to these effects, but lesser tolerance was observed with PNR-4-20 for hypothermic and cataleptic effects. Tolerance to the effects of PNR-4-20 completely recovered after drug abstinence, while residual tolerance was always observed with unbiased CB₁R agonists. Repeated treatment with PNR-4-20 and Δ⁹-THC produced asymmetric crosstolerance to hypothermic effects. Importantly, binding studies suggest PNR-4-20 produced significantly less downregulation of CB₁Rs relative to Δ⁹-THC in hypothalamus and thalamus of chronically treated mice. These studies suggest that the G protein-biased CB₁R agonist PNR-4-20 produces significantly less tolerance than unbiased cannabinoid agonists, and that the IQD analogs should be investigated further as a novel molecular scaffold for development of new therapeutics.

Potential Use of Cannabinoids for the Treatment of Pancreatic Cancer

Background: Cannabinoid extracts may have anticancer properties, which can improve cancer treatment outcomes. The aim of this review is to determine the potentially utility of cannabinoids in the treatment of pancreatic cancer.

Methods: A literature review focused on the biological effects of cannabinoids in cancer treatment, with a focus on pancreatic cancer, was conducted. In vitro and in vivo studies that investigated the effects of cannabinoids in pancreatic cancer were identified and potential mechanisms of action were assessed.

Results: Cannabinol receptors have been identified in pancreatic cancer with several studies showing in vitro antiproliferative and proapoptotic effects. The main active substances found in cannabis plants are cannabidiol (CBD) and tetrahydrocannabinol (THC). There effects are predominately mediated through, but not limited to cannabinoid receptor-1, cannabinoid receptor-2, and G-protein-coupled receptor 55 pathways. In vitro studies consistently demonstrated tumor growth-inhibiting effects with CBD, THC, and synthetic derivatives. Synergistic treatment effects have been shown in two studies with the combination of CBD/synthetic cannabinoid receptor ligands and chemotherapy in xenograft and genetically modified spontaneous pancreatic cancer models. There are, however, no clinical studies to date showing treatment benefits in patients with pancreatic cancer.

Conclusions: Cannabinoids may be an effective adjunct for the treatment of pancreatic cancer. Data on the anticancer effectiveness of various cannabinoid formulations, treatment dosing, precise mode of action, and clinical studies are lacking.

Receptor Binding Affinities of Synthetic Cannabinoids Determined by Non-Isotopic Receptor Binding Assay

A major predictor of the efficacy of natural or synthetic cannabinoids is their binding affinity to the cannabinoid type I receptor (CB1) in the central nervous system, as the main psychological effects of cannabinoids are achieved via binding to this receptor. Conventionally, receptor binding assays have been performed using isotopes, which are inconvenient owing to the effects of radioactivity. In the present study, the binding affinities of five cannabinoids for purified CB1 were measured using a surface plasmon resonance (SPR) technique as a putative non-isotopic receptor binding assay. Results were compared with those of a radio-isotope-labeled receptor binding assay. The representative natural cannabinoid Δ9-tetrahydrocannabinol and four synthetic cannabinoids, JWH-015, JWH-210, RCS-4, and JWH-250, were assessed using both the SPR biosensor assay and the conventional isotopic receptor binding assay. The binding affinities of the test substances to CB1 were determined to be (from highest to lowest) 9.52 × 10-13 M (JWH-210), 6.54 × 10-12 M (JWH-250), 1.56 × 10-11 M (Δ9-tetrahydrocannabinol), 2.75 × 10-11 M (RCS-4), and 6.80 ×10-11 M (JWH-015) using the non-isotopic method. Using the conventional isotopic receptor binding assay, the same order of affinities was observed. In conclusion, our results support the use of kinetic analysis via SPR in place of the isotopic receptor binding assay. To replace the receptor binding affinity assay with SPR techniques in routine assays, further studies for method validation will be needed in the future.

Medical Cannabis Use by Hodgkin Lymphoma Patients: Experience of a Single Center

Hodgkin lymphoma (HL) is one of the most curable malignancies. Despite its effectiveness, chemotherapy is often associated with adverse events (AEs) such as nausea, anorexia, and impairment of general well-being. Our objective was to assess the extent of medical cannabis use among HL patients and evaluate its efficacy in controlling chemotherapy-related AEs. Patterns of medical cannabis use and efficacy were evaluated using physician-completed application forms, medical files, and patient-completed questionnaires, for all consecutive adult HL patients treated at the Tel-Aviv Medical Center between June 2010 and November 2016. One-hundred and thirty-three patients met the inclusion criteria. The median age of the cohort was 37 years, 53% were male, 46% were diagnosed at an early stage, and 88% achieved a complete response to treatment. Fifty-one patients (38%) used medical cannabis. There were no significant differences in baseline characteristics between cannabis users and nonusers. Cannabis users reported improvement in pain, general well-being, appetite, and nausea in 94, 87, 82, and 79% of cases, respectively. Importantly, 81.5% reported a high overall efficacy of cannabis in relieving symptoms. AEs related to cannabis use itself were mild. Thus, medical cannabis use is prevalent in this HL cohort, and appears to be effective in ameliorating chemotherapy-related AEs.

Sleem A, Abd El Baset Mohamed Sayed M, A. Khadrawy Y, A. Morsy F. Cannabis sativa Increases Seizure Severity and Brain Lipid Peroxidation in Pentylenetetrazole-Induced Kindling in Rats

The effect of Cannabis sativa extract on chemical kindling induced in rats by the repeated intraperitoneal (ip) injections of pentylenetetrazole (PTZ) was studied. Rats were treated with PTZ (35 mg/kg) once every 48 hours for 12 times alone or with ip Cannabis sativa (20 mg/kg expressed as Δ9-THC content) 30 min prior to PTZ injection. Seizures were recorded for 20 minutes. Control rats received ip saline. Cannabis treatment caused significant elevation of mean seizure score as compared to PTZ only group after the 5th, 6th and 7th PTZ repeated injections during seizure development. In particular, cannabis caused significant elevation in the frequency of myoclonic jerks, rearing (stage 3), turn over onto one side position and back position (stage 4), and generalized tonic-clonic seizures (stage 5) compared with the PTZ only group. PTZ caused significant elevations in brain lipid peroxidation (malondialdehyde), and nitric oxide along with deceased reduced glutathione level. In addition, brain acetylcholinesterase (AChE) activity significantly decreased compared to control value after PTZ treatment. Cannabis given to PTZ treated rats caused significant increase in brain malondialdehyde and AChE activity compared to PTZ only group. Reduced glutathione level was restored by cannabis. Histopathological studies indicated the presence of spongiform changes, degenerated and necrotic neurons, inflammatory cells, and gliosis in cerebral cortex and degeneration of some Purkinje cells in the cerebellum in both PTZ- and cannabis-PTZ-treated groups. It is concluded that in an epilepsy model induced by repeated PTZ administration, cannabis increased lipid peroxidation and mean seizure score.

Cannabinoid pharmacology and therapy in gut disorders

Cannabis sp. and their products (marijuana, hashish…), in addition to their recreational, industrial and other uses, have a long history for their use as a remedy for symptoms related with gastrointestinal diseases. After many reports suggesting these beneficial effects, it was not surprising to discover that the gastrointestinal tract expresses endogenous cannabinoids, their receptors, and enzymes for their synthesis and degradation, comprising the so-called endocannabinoid system. This system participates in the control of tissue homeostasis and important intestinal functions like motor and sensory activity, nausea, emesis, the maintenance of the epithelial barrier integrity, and the correct cellular microenvironment. Thus, different cannabinoid-related pharmacological agents may be useful to treat the main digestive pathologies. To name a few examples, in irritable bowel syndrome they may normalize dysmotility and reduce pain, in inflammatory bowel disease they may decrease inflammation, and in colorectal cancer, apart from alleviating some symptoms, they may play a role in the regulation of the cell niche. This review summarizes the main recent findings on the role of cannabinoid receptors, their synthetic or natural ligands and their metabolizing enzymes in normal gastrointestinal function and in disorders including irritable bowel syndrome, inflammatory bowel disease, colon cancer and gastrointestinal chemotherapy-induced adverse effects (nausea/vomiting, constipation, diarrhea).

Novel mechanism of cannabidiol-induced apoptosis in breast cancer cell lines

Studies have emphasized an antineoplastic effect of the non-psychoactive, phyto-cannabinoid, Cannabidiol (CBD). However, the molecular mechanism underlying its antitumor activity is not fully elucidated. Herein, we have examined the effect of CBD on two different human breast cancer cell lines: the ER-positive, well differentiated, T-47D and the triple negative, poor differentiated, MDA-MB-231 cells. In both cell lines, CBD inhibited cell survival and induced apoptosis in a dose dependent manner as observed by MTT assay, morphological changes, DNA fragmentation and ELISA apoptosis assay. CBD-induced apoptosis was accompanied by down-regulation of mTOR, cyclin D1 and up-regulation and localization of PPARγ protein expression in the nuclei and cytoplasmic of the tested cells. The results suggest that CBD treatment induces an interplay among PPARγ, mTOR and cyclin D1 in favor of apoptosis induction in both ER-positive and triple negative breast cancer cells, proposing CBD as a useful treatment for different breast cancer subtypes.

Rimonabant Kills Colon Cancer Stem Cells without Inducing Toxicity in Normal Colon Organoids

Colorectal cancer (CRC), like other tumor types, is a highly heterogeneous disease. Within the tumor bulk, intra-tumoral heterogeneity is also ascribable to Cancer Stem Cells (CSCs) subpopulation, characterized by high chemoresistance and the unique ability to retain tumorigenic potential, thus associated to tumor recurrence. High dynamic plasticity of CSCs, makes the development of winning therapeutic strategies even more complex to completely eradicate tumor fuel. Rimonabant, originally synthesized as antagonist/inverse agonist of Cannabinoid Receptor 1, is able to inactivate Wnt signaling, both in vitro and in vivo, in CRC models, through inhibition of p300-histone acetyltransferase activity. Since Wnt/β-Catenin pathway is the main player underlying CSCs dynamic, this finding candidates Rimonabant as potential modulator of cancer stemness, in CRC. In this work, using established 3D cultures of primary colon CSCs, taking into account the tumor heterogeneity through monitoring of Wnt activity, we demonstrated that Rimonabant was able to reduces both tumor differentiated cells and colon CSCs proliferation and to control their survival in long term cultures. Interestingly, in ex vivo model of wild type human organoids, retaining both architecture and heterogeneity of original tissue, Rimonabant showed no toxicity against cells from healthy colon epithelium, suggesting its potential selectivity toward cancer cells. Overall, results from this work provided new insights on anti-tumor efficacy of Rimonabant, strongly suggesting that it could be a novel lead compound for CRC treatment.

Supportive Care for the Head and Neck Cancer Patient

Patients with head and neck cancers (HNC) face multiple psychosocial and physical challenges that require multidisciplinary attention and care throughout their disease process. The psychoemotional symptoms may be triggered by cosmetic disfigurement and/or functional deficits related to the cancer itself or cancer-directed treatments. These physical and emotional symptoms can be demoralizing and require acute and long-term professional assistance throughout a patient's lifespan. HNC remains one of the most challenging cancers to treat due to disfigurement, emotional suffering, social isolation, and loss of self-esteem. The emotional and physical symptoms a supportive care team can address are discussed in this chapter.

SEOM clinical guideline for treatment of cancer pain (2017)

Pain is a highly prevalent symptom in patients with cancer. Despite therapeutic advances and well-accepted treatment guidelines, a percentage of patients with pain are under-treated. Currently, it has been recognized that several barriers in pain management still exist and, in addition, there are new challenges surrounding complex subtypes of pain, such as breakthrough and neuropathic pain, requiring further reviews and recommendations. This is an update of the guide our society previously published and represents the continued commitment of SEOM to move forward and improve supportive care of cancer patients.

Mother of Berries, ACDC, or Chocolope: Examination of the Strains Used by Medical Cannabis Patients in New England

Medical marijuana patients often believe that specific strains are more efficacious at treating their conditions. The goals of this investigation were to determine: (1) how many strains of cannabis are there; (2) which strains are used by medical cannabis (MC) patients; and (3) are there any differences in the strains used by patient condition? Study I involved quantifying the number of strains listed in the online database leafly.com and categorizing these by whether the strain name included a gustatory component. MC patients (N = 455) from New England completed an anonymous online survey about their medical history and strain preferences in Study II. There were 1,987 strains listed. Hybrids were significantly more likely than Cannabis indica strains to have a gustatory title. Strain preferences were highly state/dispensary specific with one-fifth of MC patients in Maine preferring Mother of Berries (M.O.B., 21.5%). Many respondents mentioned that they had developed a time-dependent pattern with sativa use during the day and an indica for nighttime use and for improving sleep. There is some general consistency across dispensaries in that hybrid strains and C. indica were most common. Further longitudinal and controlled investigations are necessary to identify the strains that are most efficacious for specific conditions.

Cannabis use among patients at a comprehensive cancer center in a state with legalized medicinal and recreational use

BACKGROUND

Cannabis is purported to alleviate symptoms related to cancer treatment, although the patterns of use among cancer patients are not well known. This study was designed to determine the prevalence and methods of use among cancer patients, the perceived benefits, and the sources of information in a state with legalized cannabis.

METHODS

A cross‐sectional, anonymous survey of adult cancer patients was performed at a National Cancer Institute–designated cancer center in Washington State. Random urine samples for tetrahydrocannabinol provided survey validation.

RESULTS

Nine hundred twenty‐six of 2737 eligible patients (34%) completed the survey, and the median age was 58 years (interquartile range [IQR], 46‐66 years). Most had a strong interest in learning about cannabis during treatment (6 on a 1‐10 scale; IQR, 3‐10) and wanted information from cancer providers (677 of 911 [74%]). Previous use was common (607 of 926 [66%]); 24% (222 of 926) used cannabis in the last year, and 21% (192 of 926) used cannabis in the last month. Random urine samples found similar percentages of users who reported weekly use (27 of 193 [14%] vs 164 of 926 [18%]). Active users inhaled (153 of 220 [70%]) or consumed edibles (154 of 220 [70%]); 89 (40%) used both modalities. Cannabis was used primarily for physical (165 of 219 [75%]) and neuropsychiatric symptoms (139 of 219 [63%]). Legalization significantly increased the likelihood of use in more than half of the respondents.

CONCLUSIONS

This study of cancer patients in a state with legalized cannabis found high rates of active use across broad subgroups, and legalization was reported to be important in patients' decision to use. Cancer patients desire but are not receiving information about cannabis use during their treatment from oncology providers. Cancer 2017;123:4488‐97. © 2017 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.

Cannabis use is common among patients receiving treatment at a large cancer center in a state with legalized recreational and medical cannabis. Active use is reported across broad demographic and diagnostic cancer subgroups, and legalization is reported to be important in patients' decision to use.

The Cannabinoid Receptor Interacting Proteins 1 of zebrafish are not required for morphological development, viability or fertility

The Cannabinoid Receptor Interacting Protein 1 (Cnrip1) was discovered as an interactor with the intracellular region of Cannabinoid Receptor 1 (CB1R, also known as Cnr1 or CB1). Functional assays in mouse show cannabinoid sensitivity changes and Cnrip1 has recently been suggested to control eye development in Xenopus laevis. Two Cnrip1 genes are described in zebrafish, cnrip1a and cnrip1b. In situ mRNA hybridisation revealed accumulation of mRNA encoding each gene primarily in brain and spinal cord, but also elsewhere. For example, cnrip1b is expressed in forming skeletal muscle. CRISPR/Cas9 genome editing generated predicted null mutations in cnrip1a and cnrip1b. Each mutation triggered nonsense-mediated decay of the respective mRNA transcript. No morphological or behavioural phenotype was observed in either mutant. Moreover, fish lacking both Cnrip1a and Cnrip1b both maternally and zygotically are viable and fertile and no phenotype has so far been detected despite strong evolutionary conservation over at least 400 Myr.

Recent advances in understanding and managing cancer pain

Cancer pain remains a significant clinical problem worldwide. Causes of cancer pain are multifactorial and complex and are likely to vary with an array of tumor-related and host-related factors and processes. Pathophysiology is poorly understood; however, new laboratory research points to cross-talk between cancer cells and host’s immune and neural systems as an important potential mechanism that may be broadly relevant to many cancer pain syndromes. Opioids remain the most effective pharmaceuticals used in the treatment of cancer pain. However, their role has been evolving due to emerging awareness of risks of chronic opioid therapy. Despite extensive research efforts, no new class of analgesics has been developed. However, many potential therapeutic targets that may lead to the establishment of new pharmaceuticals have been identified in recent years. It is also expected that the role of non-pharmacological modalities of treatment will grow in prominence. Specifically, neuromodulation, a rapidly expanding field, may play a major role in the treatment of neuropathic cancer pain provided that further technological progress permits the development of non-invasive and inexpensive neuromodulation techniques.

Systematic review of the potential role of cannabinoids as antiproliferative agents for urological cancers

INTRODUCTION

The palliative effects of cannabis sativa (marijuana), which include appetite stimulation, attenuation of nausea and emesis, and pain relief, are well known. The active components of cannabis sativa (cannabinoids) and their derivatives have received growing interest due to their diverse pharmacological activities, such as cell growth inhibition and tumour regression. The aim of this review is to look at the current evidence on the antiproliferative effects of cannabinoids in urological malignancies, including renal, prostate, bladder, and testicular cancers.

METHODS

We conducted a systematic review of studies exploring the effect of cannabinoids on tumour activity, including all study types except expert opinions. A formal search was run on Medline database from 1946 to September 2016, along with a hand-search on PubMed for relevant studies.

RESULTS

The search yielded a total of 93 studies from Medline and PubMed, of which 23 studies were included in the final analysis. To date, there are various in vitro studies elucidating the potential mechanism of action of cannabinoids for urological cancers, along with population-based studies specifically for testicular malignancies. To date, no clinical trials have been conducted for urological cancer patients.

CONCLUSIONS

These results demonstrate that the role of endocannabinoids for urological malignancies is an area of active research. Further research is required not only to evaluate the crosstalk between cancer signaling pathways and cannabinoids, but also large randomized clinical studies with urological patients need to be conducted before cannabinoids can be introduced as potential therapeutic options for urological neoplasms.