False News of a Cannabis Cancer Cure

[Developments in the digitalization of public health since 2020 : Examples from the Leibniz ScienceCampus Digital Public Health Bremen]

Digital public health has received a significant boost in recent years, especially due to the demands associated with the COVID-19 pandemic. In this report, we provide an overview of the developments in digitalization in the field of public health in Germany since 2020 and illustrate these with examples from the Leibniz ScienceCampus Digital Public Health Bremen (LSC DiPH).The following topics are central: How do digital survey methods as well as digital biomarkers and artificial intelligence methods shape modern epidemiology and prevention research? What is the status of digitalization in public health offices? Which approaches to health economics evaluation of digital public health interventions have been utilized so far? What is the status of training and further education in digital public health?The first years of the Leibniz ScienceCampus Digital Public Health Bremen (LSC DiPH) were also strongly influenced by the COVID-19 pandemic. Repeated population-based digital surveys of the LSC indicated an increase in use of health apps in the population, for example, in applications to support physical activity. The COVID-19-pandemic has also shown that the digitalization of public health enhances the risk of misinformation and disinformation.

Framing substance use as "recreational" is neither accurate nor helpful for prevention purposes

This debate paper discusses six reasons why the term "recreational substance use" should be avoided. (1) Social norms and beliefs are drivers of behavior; therefore, the normalized use of the term conveys injunctive norms of a fully socially acceptable substance. Injunctive norms are the most important drivers of initiation into substance use. (2) The illusion of being in control, suggesting that if consumed for leisure and recreation it can easily be controlled; (3) Idealized social representations that fuel an idealized image of an alternative glamourous or mindful consumption culture; (4) Downplaying potential harms; (5) The implicit promise of everyday pleasure, the ever-growing potency of cannabis products does not fit the narrative of its use for recreation; (6) Industry as a trojan horse branding discourse of the concept of medical cannabis to normalize the image of non-medical use: to complement "therapeutic" with "recreational". "Recreational use" is a subjective ill-defined term. This debate paper aims to find a better terminological solution, honestly denominating with a neutral, unbiased, and objective connotation what is now called "recreational use". Thus, we propose using the term "non-therapeutic" use.

Understanding Cannabis-Related Information Needs: An Analysis of Inquiries to the National Cancer Institute's Cancer Information Service

Purpose: Given increased cannabis use for medical and nonmedical purposes alike, there is growing public interest related to the potential risks and benefits of cannabis use, particularly related to cancer. The purpose of this descriptive study was to analyze cannabis inquiries to the National Cancer Institute's Cancer Information Service (CIS). Materials and Methods: From September 2018 to June 2023, 190,070 noncannabis and 425 cannabis inquiries were documented by the CIS. Cannabis inquiries were delineated into two categories: nonmedical cannabis (NMC, n=240) or medical cannabis (MC, n=185). Chi-square tests were performed to determine differences between noncannabis and cannabis inquiries and descriptive analyses were used to identify patterns within cannabis-specific inquiries. Results: Statistically significant differences between noncannabis and cannabis inquiries were observed. In addition, there were variations in MC and NMC inquiries. For example, 73% of MC inquiries originated from cancer survivors and caregivers, whereas almost half of NMC inquiries (48%) were from individuals identifying as tobacco users. MC and NMC inquiries also differed by CIS access channel (e.g., instant chat, telephone), language used (English vs. Spanish), discussions of cancer continuum phases and cancer sites, and referrals provided to individuals for additional information and resources. Conclusion: Cannabis-related information needs of the public-as documented by the CIS-varied by several factors. Health information sources such as the CIS can help address cannabis-related questions and concerns, while noting differences in who is inquiring, how, and why.

Medicinal Cannabis Guidance and Resources for Health Professionals to Inform Clinical Decision Making

PURPOSE

Interest in the use of cannabis as a medicine has markedly increased during the last decade, with an unprecedented number of patients now seeking advice or prescriptions for medicinal cannabis. Unlike other medicines prescribed by physicians, many medicinal cannabis products have not undergone standard clinical trial development required by regulatory authorities. Different formulations with varying strengths and ratios of tetrahydrocannabinol and cannabidiol are available, and this diversity of medicinal cannabis products available for a myriad of therapeutic indications adds to the complexity. Physicians face challenges and barriers in their clinical decision making with medicinal cannabis because of current evidence limitations. Research efforts to address evidence limitations are ongoing; in the interim, educational resources and clinical guidance are being developed to address the gap in clinical information and support the needs of health professionals.

METHODS

This article provides an overview of various resources that health professionals may use when seeking information about medicinal cannabis in the absence of high-quality evidence and clinical guidelines. It also identifies examples of international evidence-based resources that support clinical decision making with medicinal cannabis.

FINDINGS

Similarities and differences between international examples of guidance and guideline documents are identified and summarized.

IMPLICATIONS

Guidance can help guide physicians in the individualized choice and dose of medicinal cannabis. Before quality clinical trials and regulator-approved products with risk management programs, safety data require clinical and academic collaborative pharmacovigilance.

Advertising Alternative Cancer Treatments and Approaches on Meta Social Media Platforms: Content Analysis

BACKGROUND

Alternative cancer treatment is associated with a greater risk of death than cancer patients undergoing conventional treatments. Anecdotal evidence suggests cancer patients view paid advertisements promoting alternative cancer treatment on social media, but the extent and nature of this advertising remain unknown. This context suggests an urgent need to investigate alternative cancer treatment advertising on social media.

OBJECTIVE

This study aimed to systematically analyze the advertising activities of prominent alternative cancer treatment practitioners on Meta platforms, including Facebook, Instagram, Messenger, and Audience Network. We specifically sought to determine (1) whether paid advertising for alternative cancer treatment occurs on Meta social media platforms, (2) the strategies and messages of alternative cancer providers to reach and appeal to prospective patients, and (3) how the efficacy of alternative treatments is portrayed.

METHODS

Between December 6, 2021, and December 12, 2021, we collected active advertisements from alternative cancer clinics using the Meta Ad Library. The information collected included identification number, URL, active/inactive status, dates launched/ran, advertiser page name, and a screenshot (image) or recording (video) of the advertisement. We then conducted a content analysis to determine how alternative cancer providers communicate the claimed benefits of their services and evaluated how they portrayed alternative cancer treatment efficacy.

RESULTS

We identified 310 paid advertisements from 11 alternative cancer clinics on Meta (Facebook, Instagram, or Messenger) marketing alternative treatment approaches, care, and interventions. Alternative cancer providers appealed to prospective patients through eight strategies: (1) advertiser representation as a legitimate medical provider (n=289, 93.2%); (2) appealing to persons with limited treatments options (n=203, 65.5%); (3) client testimonials (n=168, 54.2%); (4) promoting holistic approaches (n=121, 39%); (5) promoting messages of care (n=81, 26.1%); (6) rhetoric related to science and research (n=72, 23.2%); (7) rhetoric pertaining to the latest technology (n=63, 20.3%); and (8) focusing treatment on cancer origins and cause (n=43, 13.9%). Overall, 25.8% (n=80) of advertisements included a direct statement claiming provider treatment can cure cancer or prolong life.

CONCLUSIONS

Our results provide evidence alternative cancer providers are using Meta advertising products to market scientifically unsupported cancer treatments. Advertisements regularly referenced "alternative" and "natural" treatment approaches to cancer. Imagery and text content that emulated evidence-based medical providers created the impression that the offered treatments were effective medical options for cancer. Advertisements exploited the hope of patients with terminal and poor prognoses by sharing testimonials of past patients who allegedly were cured or had their lives prolonged. We recommend that Meta introduce a mandatory, human-led authorization process that is not reliant upon artificial intelligence for medical-related advertisers before giving advertising permissions. Further research should focus on the conflict of interest between social media platforms advertising products and public health.

Using Social Media Data to Investigate Public Perceptions of Cannabis as a Medicine: Narrative Review

BACKGROUND

The use and acceptance of medicinal cannabis is on the rise across the globe. To support the interests of public health, evidence relating to its use, effects, and safety is required to match this community demand. Web-based user-generated data are often used by researchers and public health organizations for the investigation of consumer perceptions, market forces, population behaviors, and for pharmacoepidemiology.

OBJECTIVE

In this review, we aimed to summarize the findings of studies that have used user-generated text as a data source to study medicinal cannabis or the use of cannabis as medicine. Our objectives were to categorize the insights provided by social media research on cannabis as medicine and describe the role of social media for consumers using medicinal cannabis.

METHODS

The inclusion criteria for this review were primary research studies and reviews that reported on the analysis of web-based user-generated content on cannabis as medicine. The MEDLINE, Scopus, Web of Science, and Embase databases were searched from January 1974 to April 2022.

RESULTS

We examined 42 studies published in English and found that consumers value their ability to exchange experiences on the web and tend to rely on web-based information sources. Cannabis discussions have portrayed the substance as a safe and natural medicine to help with many health conditions including cancer, sleep disorders, chronic pain, opioid use disorders, headaches, asthma, bowel disease, anxiety, depression, and posttraumatic stress disorder. These discussions provide a rich resource for researchers to investigate medicinal cannabis-related consumer sentiment and experiences, including the opportunity to monitor cannabis effects and adverse events, given the anecdotal and often biased nature of the information is properly accounted for.

CONCLUSIONS

The extensive web-based presence of the cannabis industry coupled with the conversational nature of social media discourse results in rich but potentially biased information that is often not well-supported by scientific evidence. This review summarizes what social media is saying about the medicinal use of cannabis and discusses the challenges faced by health governance agencies and professionals to make use of web-based resources to both learn from medicinal cannabis users and provide factual, timely, and reliable evidence-based health information to consumers.

The quality of health information provided on web sites selling cannabis to consumers in Canada is poor

BACKGROUND

Cannabis is used by millions of people for both medical and recreational purposes, and this use is even greater in jurisdictions where it is legalized, such as Canada. Online cannabis vendors have gained popularity for purchasing cannabis due to easy access and convenience to consumers. The objective of this study was to evaluate the quality of health information provided by web sites of cannabis vendors selling products to Canadian consumers and to further identify trends in the information provided.

METHODS

Six different searches were conducted on Google.ca, and the first 40 webpages of each search were screened for eligibility. A total of 33 unique web sites of cannabis vendors selling products to Canadian consumers were identified and included. The DISCERN instrument, which consists of 16 questions divided into three sections, was used to evaluate the quality of cannabis-related health information on these web sites.

RESULTS

Across the 33 web sites, the average of the summed DISCERN scores was 36.83 (SD = 9.73) out of 75, and the mean score for the overall quality of the publication (DISCERN question 16) was 2.41 (SD = 0.71) out of 5. Many of these web sites failed to discuss uncertainties in research evidence on cannabis, the impact of cannabis use on quality of life, alternatives to cannabis use, risks associated with cannabis use, and lacked references to support claims on effects and benefits of use.

CONCLUSION

Our findings indicate that the quality of cannabis-related health information provided by online vendors is poor. Healthcare providers should be aware that patients may use these web sites as primary sources of information and appropriately caution patients while directing them to high-quality sources. Future research should serve to replicate this study in other jurisdictions and assess the accuracy of information provided by online cannabis vendors, as this was outside the scope of the DISCERN instrument.

Perspectives of pediatric oncologists and palliative care physicians on the therapeutic use of cannabis in children with cancer

BACKGROUND

Children with cancer are increasingly using cannabis therapeutically.

AIM

The purpose of this study was to determine the perspectives and practices of pediatric oncologists and palliative care physicians regarding the use of cannabis for medical purposes among children with cancer.

METHODS

A self-administered, voluntary, cross-sectional, deidentified online survey was sent to all pediatric oncologists and palliative care physicians in Canada between June and August 2020. Survey domains included education, knowledge, and concerns about cannabis, views on its effectiveness, and the importance of cannabis-related research. Data were analyzed using descriptive statistics.

RESULTS

In total, 122/259 (47.1%) physicians completed the survey. Although 62.2% of the physicians completed some form of training about medical cannabis, nearly all (95.8%) desired to know more about the dosing, side effects, and safety of cannabis. Physicians identified a potential role of cannabis in the management of nausea and vomiting (85.7%), chronic pain (72.3%), cachexia/poor appetite (67.2%), and anxiety or depression (42.9%). Only four (0.3%) physicians recognized cannabis to be potentially useful as an anticancer agent. Nearly all physicians reported that cannabis-related research for symptom relief is essential (91.5%) in pediatric oncology, whereas 51.7% expressed that future studies are necessary to determine the anticancer effects of cannabis.

CONCLUSIONS

Our findings indicate that most pediatric oncologists and palliative care physicians recognize a potential role for cannabis in symptom control in children with cancer. Well-conducted studies are required to create evidence for cannabis use and promote shared decision making with pediatric oncology patients and their caregivers.

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.

Cannabinoid consumption among cancer patients receiving systemic anti-cancer treatment in the Netherlands

PURPOSE

Despite the inconclusiveness regarding health effects of cannabinoids among cancer patients, studies from non-European countries suggest that the medical-intended consumption of such products by this patient group is significant. The current study analyses cannabinoid usage among oncology patients receiving systemic treatment in the Netherlands.

METHODS

The current study included adult patients receiving intravenous systemic therapy at Maastricht Comprehensive Cancer Centre, for a solid malignancy. Participants were asked to complete an anonymous questionnaire including questions on demographic variables, clinical variables and cannabinoid consumption.

RESULTS

A total of 153 patients with solid cancer were included in this study. Almost 25% reported usage of cannabinoids for medical purposes, with 15% of the patients currently using the substance. Additionally, 18% of non-users considered future medical usage. In 48% of the cases, consumption was reported by the oncologist. The proposed anti-cancer effect was reported by 46% of the users as motivation for consumption. Current users were mainly palliative patients and 54% of the users were undergoing immunotherapy. Intention of treatment and type of therapy were predictive factors for consumption. Cannabinoid-oil was the most frequently used way of consumption.

CONCLUSION

This study underlines the high number of cannabinoid users among oncology patients in the Netherlands in presumed absence of clinical guidance. It highlights the essence of a pro-active role of the clinician, assessing cannabinoid usage and educating the patients on the most recent evidence regarding its potential benefits and risks. Further studies on clinical decision making and efficacy of cannabinoids are recommended, to improve clinical guidance.

Impact of Cannabinoid Compounds on Skin Cancer

Drugs targeting the endocannabinoid system are of interest as potential systemic chemotherapeutic treatments and for palliative care in cancer. In this context, cannabinoid compounds have been successfully tested as a systemic therapeutic option in preclinical models over the past decades. Recent findings have suggested an essential function of the endocannabinoid system in the homeostasis of various skin functions and indicated that cannabinoids could also be considered for the treatment and prophylaxis of tumour diseases of the skin. Cannabinoids have been shown to exert their anticarcinogenic effects at different levels of skin cancer progression, such as inhibition of tumour growth, proliferation, invasion and angiogenesis, as well as inducing apoptosis and autophagy. This review provides an insight into the current literature on cannabinoid compounds as potential pharmaceuticals for the treatment of melanoma and squamous cell carcinoma.

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.

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.

Challenges for Clinical Cannabis and Cannabinoid Research in the United States

Significant changes have occurred in the policy landscape surrounding cannabis legalization, production, and use around the globe and across the United States. With widespread availability of novel cannabis and cannabis-based products, there is an urgent need to understand their safety and effectiveness for medical indications. Three primary barriers contribute to the difficulty in initiating research geared toward answering the most pressing public health questions: the US regulatory status of cannabis and cannabinoids, sources for cannabis and cannabinoid study medications, and limited funding and resources to support studies. Despite these hurdles, research is rapidly increasing, and recent changes in the United States have paved the way for exciting new work. Here, challenges and barriers to cannabis and cannabinoid research are described from the perspectives of the National Institute on Drug Abuse, National Institutes of Health; the US Food and Drug Administration; and 2 clinical researchers. Barriers specifically to studying cannabis, cannabinoids, and cancer are emphasized.

Cannabis for pain: a cross-sectional survey of the patient information quality on the Internet

BACKGROUND

Cannabis has increasingly become an alternative treatment for chronic pain, however, there is evidence of concomitant negative health effects with its long-term usage. Patients contemplating cannabis use for pain relief commonly see information online but may not be able to identify trustworthy and accurate sources, therefore, it is imperative that healthcare practitioners play a role in assisting them in discerning the quality of information. The present study assesses the quality of web-based consumer health information available at the intersection of cannabis and pain.

METHODS

A cross-sectional quality assessment of website information was conducted. Three countries were searched on Google: Canada, the Netherlands, and the USA. The first 3 pages of generated websites were used in each of the 9 searches. Eligible websites contained cannabis consumer health information for pain treatment. Only English-language websites were included. Encyclopedias (i.e. Wikipedia), forums, academic journals, general news websites, major e-commerce websites, websites not publicly available, books, and video platforms were excluded. Information presented on eligible websites were assessed using the DISCERN instrument. The DISCERN instrument consists of three sections, the first focusing on the reliability of the publication, the second investigating individual aspects of the publication, and the third providing an overall averaged score.

RESULTS

Of 270 websites identified across searches, 216 were duplicates, and 18 were excluded based on eligibility criteria, resulting in 36 eligible websites. The average summed DISCERN score was 48.85 out of 75.00 (SD = 8.13), and the average overall score (question 16) was 3.10 out of 5.00 (SD = 0.62). These overall scores were calculated from combining the scores for questions 1 through 15 in the DISCERN instrument for each website. Websites selling cannabis products/services scored the lowest, while health portals scored the highest.

CONCLUSION

These findings indicate that online cannabis consumer health information for the treatment/management of pain presents biases to readers. These biases included websites: (1) selectively citing studies that supported the benefits associated with cannabis use, while neglecting to mention those discussing its risks, and (2) promoting cannabis as "natural" with the implication that this equated to "safe". Healthcare providers should be involved in the guidance of patients' seeking and use of online information on this topic.

Medicinal cannabis: knowledge, beliefs, and attitudes of Colombian psychiatrists

Background

The use of cannabinoids in mental health has gained strength in recent years due to emerging scientific evidence and the lifting of prohibitionist laws that prevailed for years in many countries, including Colombia. This study describes the results of a survey of Colombian psychiatrists on some aspects of medicinal cannabis, such as attitudes towards its potential use, perceived knowledge, and beliefs surrounding its regulation and safety.

Methods

We conducted a cross-sectional survey of 145 psychiatrists in 14 territories of Colombia between November 2019 and July 2020. The survey consisted of 28 items on topics related to medicinal cannabis, including attitudes and clinical experience (4 items), perceived knowledge (4 items), indications for use in psychiatric pathologies (6 items), indications for use in nonpsychiatric pathologies (8 items), and concerns and awareness about safety and efficacy (6 items). The results were summarized using descriptive statistics. In addition, possible associations among variables were examined using Fisher’s exact test.

Results

Eighty-two percent of the psychiatrists agreed that medical cannabis should be available for different medical conditions, and 73.1% stated that they wanted to be able to prescribe it. However, 66.2% said they did not know how to help their patients legally access it, and only 25% understood the legal status of medicinal cannabis in the country. The mental health indications that received the highest approval levels for cannabis use were insomnia (35.2%), anxiety disorders (29%), and agitation in dementia (18.6%). The greatest disapproval of cannabis use was indicated for schizophrenia, with 66.9%. The most approved nonpsychiatric medical conditions were cancer-related chronic pain (87.6%), chemotherapy-related nausea and vomiting (78.6%), and chronic pain not associated with cancer (72.4%). Multinomial stepwise logistic regression analysis showed that female psychiatrists who did not agree with MC to treat psychiatric symptoms were more likely to agree with non-psychiatric use.

Conclusions

Our results showed that this sample of Colombian psychiatrists have a favorable attitude towards the prescription of medicinal cannabis; however, there is a serious lack of knowledge of the legal status of medicinal cannabis in the country and the methods through which patients can gain access to government-regulated products. Most of them approve the use of MC for nonpsychiatric conditions and, in general, disapprove of its use in mental illnesses. They generally consider medicinal cannabis as a safe treatment compared to other psychotropic drugs and medications with potential risk of dependence, such as opioids and/or benzodiazepines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-021-00083-z.

Scoping Review and Meta-Analysis Suggests that Cannabis Use May Reduce Cancer Risk in the United States

Introduction: Cannabis smoke contains carcinogens similar to tobacco, in addition to compounds with antitumor activity. Cannabis use reduces the risk of obesity and cannabinoids inhibit chronic inflammation, known causes of cancer. The net effect of Cannabis use on cancer risk is not known. Objective: To examine the association between Cannabis use and cancer risk in the United States. Methods: Identify and analyze published data on cancer risk in Cannabis users. Results: A total of 55 data points, consisting of risk ratios of cancer in Cannabis users and nonusers, were identified from 34 studies. Of these, 5 did not contain data essential for inclusion in the meta-analysis. The remaining data showed a nonsignificant trend to an association with reduced risk (relative risk [RR]=0.90, p>0.06, N=50) although heterogeneity is high (I²=72.4%). Removal of data with high risk of selection bias (defined as those from North Africa and those that failed to adjust for tobacco) and data with high risk of performance bias (defined as those with fewer than 20 cases or controls among Cannabis users) resulted in an RR <1.0 (RR=0.86, p<0.017, N=24) and large effect size (Hedges g=0.66), but did not decrease heterogeneity (I²=74.9). Of all cancer sites, only testicular cancer showed an RR value >1, although this was not significant and had a negligible effect size (RR=1.12, p=0.3, Hedges g=0.02). Following removal of testicular cancers the remaining data showed a decrease in risk (RR=0.87, p<0.025, N=41). Cancers of the head and neck showed a negative association with cancer risk (RR=0.83, p<0.05), with a large effect size (Hedges g=0.55), but high heterogeneity (I²=79.2%). RR did not reach statistical significance in the remaining cancer site categories (lung, testicular, obesity-associated, other). The data are consistent with a negative association between Cannabis use and nontesticular cancer, but there is low confidence in this result due to high heterogeneity and a paucity of data for many cancer types.

Differences between cancer patients and others who use medicinal Cannabis

BACKGROUND

Cancer patients have been at the forefront of policy discussions leading to legalization of medical Cannabis (marijuana). Unfortunately, Cannabis use among those with cancer is poorly understood.

METHODS

A diverse group of patients seeking certification for medical Cannabis in the state of Michigan were surveyed at the time of their presentation to medical dispensaries. The survey assessed demographics, employment/disability, pain, physical functioning, mental health, mode of Cannabis use, and frequency/amount of Cannabis use. Chi-square and t-tests were performed to compare those who did and did not endorse cancer diagnosis.

RESULTS

Analysis of data from 1485 adults pursuing medical Cannabis certification, including 72 (4.8%) reporting a cancer diagnosis, indicated that those with cancer were older [mean age 53.4 years (SD = 10.5) vs. 44.7 years (SD = 13.0); p<0.001] than those without cancer. They also differed regarding employment status (p<0.001; working: 20.8% vs. 46.2%; disabled: 44.4% vs. 26.5% for those with vs. those without cancer, respectively). Those with cancer used less Cannabis (p = 0.033 for quantity used) and used Cannabis less often (p = 0.032 for frequency of use); they less frequently endorsed smoking Cannabis (80% vs 91%; p = 0.015). There was a non-significant trend to increased edible use in those with cancer (57% vs. 44%; p = 0.052).

CONCLUSIONS

Patients with cancer who are seeking medical Cannabis are different from those seeking medical Cannabis without cancer, and they report using Cannabis differently. Further research to characterize the patterns and consequences of Cannabis use in cancer patients is needed.

Understanding cancer survivors' reasons to medicate with cannabis: A qualitative study based on the theory of planned behavior

Background

Prior to nonmedical cannabis legalization in Canada, individuals were only able to access cannabis legally through licensed producers with medical authorization. Now with an additional legal access system designed for nonmedical purposes, it is unclear what factors influence cancer survivors’ decisions to medicate or not medicate cannabis as a complementary therapy to alleviate their cancer symptoms.

Methods

We recruited cancer survivors via social media. Interested individuals were purposively sampled to ensure maximization in terms of age, sex, and province of residence. Constructs of the Theory of Planned Behavior were explored during the telephone interviews as participants described what influenced their decisions to medicate or not medicate cannabis to manage their symptoms.

Results

Interviews were conducted with 33 cancer survivors. All individuals believed that cannabis would manage their cancer symptoms. Those that chose to medicate with cannabis provided a variety of reasons, including that cannabis was a more natural alternative; that it reduced their overall number of prescription drugs; and that safer products had become available with the legalization of nonmedical cannabis. Some individuals also indicated that support from physicians and validation from family and friends were important in their decision to medicate with cannabis. Individuals who opted not to medicate with cannabis raised concerns about the lack of scientific evidence and/or possible dependency issues. Some also felt their physician's disapproval was a barrier to considering cannabis use.

Conclusions

The findings revealed that recreational legalization made using cannabis appear safer and easier to access for some cancer survivors. However, physicians’ censure of cannabis use for symptom management was a barrier for survivors considering its use.

Lack of evidence for the effectiveness or safety of over-the-counter cannabidiol products

Over the past 5 years, public interest in the potential health benefits of cannabidiol (CBD) has increased exponentially, and a wide range of over-the-counter (OTC) preparations of CBD are now available. A substantial proportion of the population appears to have used these products, yet the extent to which they are effective or safe is unclear. We reviewed the evidence for whether CBD has significant pharmacological and symptomatic effects at the doses typically found in OTC preparations. We found that most of the evidence for beneficial effects is derived from studies of pure, pharmaceutical grade CBD at relatively high doses. Relatively few studies have examined the effect of OTC CBD preparations, or of CBD at low doses. Thus, at present, there is little evidence that OTC CBD products have health benefits, and their safety has not been investigated. Controlled trials of OTC and low-dose CBD preparations are needed to resolve these issues.

Association Between Marijuana Use and Risk of Cancer: A Systematic Review and Meta-analysis

Importance

Marijuana use is common and growing in the United States amid a trend toward legalization. Exposure to tobacco smoke is a well-described preventable cause of many cancers; the association of marijuana use with the development of cancer is not clear.

Objective

To assess the association of marijuana use with cancer development.

Data Sources

A search of PubMed, Embase, PsycINFO, MEDLINE, and the Cochrane Library was conducted on June 11, 2018, and updated on April 30, 2019. A systematic review and meta-analysis of studies published from January 1, 1973, to April 30, 2019, and references of included studies were performed, with data analyzed from January 2 through October 4, 2019.

Study Selection

English-language studies involving adult marijuana users and reporting cancer development. The search strategy contained the following 2 concepts linked together with the AND operator: marijuana OR marihuana OR tetrahydrocannabinol OR cannabinoid OR cannabis; AND cancer OR malignancy OR carcinoma OR tumor OR neoplasm.

Data Extraction and Synthesis

Two reviewers independently reviewed titles, abstracts, and full-text articles; 3 reviewers independently assessed study characteristics and graded evidence strength by consensus.

Main Outcomes and Measures

Rates of cancer in marijuana users, with ever use defined as at least 1 joint-year exposure (equivalent to 1 joint per day for 1 year), compared with nonusers. Meta-analysis was conducted if there were at least 2 studies of the same design addressing the same cancer without high risk of bias when heterogeneity was low to moderate for the following 4 cancers: lung, head and neck squamous cell carcinoma, oral squamous cell carcinoma, and testicular germ cell tumor (TGCT), with comparisons expressed as odds ratios (ORs) with 95% CIs.

Results

Twenty-five English-language studies (19 case-control, 5 cohort, and 1 cross-sectional) were included; few studies (n = 2) were at low risk of bias. In pooled analysis of case-control studies, ever use of marijuana was not associated with head and neck squamous cell carcinoma or oral cancer. In pooled analysis of 3 case-control studies, more than 10 years of marijuana use (joint-years not reported) was associated with TGCT (OR, 1.36; 95% CI, 1.03-1.81; P = .03; I2 = 0%) and nonseminoma TGCT (OR, 1.85; 95% CI, 1.10-3.11; P = .04; I2 = 0%). Evaluations of ever use generally found no association with cancers, but exposure levels were low and poorly defined. Findings for lung cancer were mixed, confounded by few marijuana-only smokers, poor exposure assessment, and inadequate adjustment; meta-analysis was not performed for several outcomes.

Conclusions and Relevance

Low-strength evidence suggests that smoking marijuana is associated with developing TGCT; its association with other cancers and the consequences of higher levels of use are unclear. Long-term studies in marijuana-only smokers would improve understanding of marijuana's association with lung, oral, and other cancers.

Trial Registration

PROSPERO identifier: CRD42018102457.