Perception and Consumption of Cannabis Among Danish Patients with End-Stage Cancer Receiving Palliative Care: A Cross-Sectional Survey

Abstract

Introduction:

In recent years, cannabis has gained increasing attention in patients. Studies have reported that some patients with cancer self-medicate with cannabis as adjunct palliative therapy.

Objectives:

This study aimed to explore the perception and consumption of cannabis for medical purposes in patients with end-stage cancer.

Design:

This was a cross-sectional perception survey.

Setting/subjects:

A study-specific questionnaire, stratified by three subgroups based on cannabis consumption history, was administered to patients referred to a Danish palliative care unit. The subgroups were experienced respondents, either a) current or b) prior consumers, and c) naïve respondents who had never consumed cannabis. In addition to demographic and clinical parameters, respondents were asked about their perception of cannabis in relation to symptom relief and curative effect on cancer.

Results:

The response rate was 67% (n = 160) among 239 eligible patients. The overall prevalence of cannabis consumption was 24% (n = 39) further characterized as 10% current consumers and 14% prior consumers. Of all respondents, 68% perceived cannabis to have a symptom-relieving effect and 29% perceived cannabis to have a cancer curative effect. These perceptions were most pronounced among current consumers (94% and 59%, respectively), followed by prior consumers (82% and 46%, respectively) and naïve respondents (61% and 22%, respectively).

Conclusions:

Majority of respondents with end-stage cancer perceived cannabis to have a symptom-relieving effect and 24% reported experience with cannabis consumption, either currently or in the past. Current and prior cannabis consumers were more likely to believe in a cancer curative effect of cannabis than naïve respondents.

Introduction

Cancer is often accompanied by pain and other distressing symptoms, contributing to a decline in physical health and quality of life (QoL). Thus, patients with end-stage cancer receive palliative care to stabilize physical functioning, promote sociopsychological support, and improve QoL.^1–4 In Denmark, palliative care is provided at a basic level in hospitals, primary care, and by general practitioners. Patients with complex symptoms or situations can access specialized palliative care from outgoing palliative care teams, hospices, or hospital-based units.

The exploration of cannabis as a potential complementary medicine for patients with cancer has gained attention, particularly in the management of various symptoms, including pain, nausea and vomiting, loss of appetite, sleeplessness, anxiety and depression, neuropathy, and fatigue.^5–9 However, it is emphasized that the quality of evidence supporting these effects is generally low, and cannabis medicine products varied widely in terms of composition, dose, and effectiveness.^10,11

In Denmark, a national medicinal cannabis pilot program was initiated in January 2018 with the aim of exploring consumption of medicinal cannabis within a legal framework that adheres to the quality and safety standards for production, distribution, and prescription. This allows physicians to prescribe medicinal cannabis for conditions such as multiple sclerosis, spinal cord injury, nausea related to chemotherapy, or neuropathic pain. Independent of the pilot program, physicians can prescribe single cannabinoids manufactured in pharmacies. However, limited clinical evidence and lack of clinical guidelines have been reported by physicians as factors causing reluctance to prescribe and counsel patients on cannabis consumption, as has been reported in other countries.^12–15

International research from countries such as Canada, the United States, Australia, and Israel has indicated the widespread consumption of cannabis among patients with cancer.^16–25 Patients have cited the management of cancer-related pain as the primary reason for cannabis consumption, as pain relief and alleviation of other distressing symptoms contribute to an enhanced sense of well-being. Some studies even indicate that patients express a belief in the potential curative effects of cannabis in cancer.^{16,17,20,21,24}

In a Danish study involving a general oncology population of nearly 3,000 patients from two hospitals, 13% of the patients reported cannabis consumption. In that study, cannabis consumption correlated with decreased reported QoL. Patients reported symptom management as the primary reason for cannabis consumption, and many experienced relief from cancer-related symptoms.²⁴

A qualitative study comprising interviews with 20 patients receiving palliative care for cancer was conducted at our institution. All patients reported cannabis consumption, with 40% as a prescribed treatment and 60% for self-medication. The study gathered insights from patients with end-stage cancer regarding their motivations for cannabis consumption and the outcomes they experienced. The findings of the study revolved around key themes, including the desire to survive cancer, the sense of hope, the miraculous, and perceived effects of cannabis. Informants expressed relief of symptoms as a secondary motivation for cannabis consumption, with the primary goal being a curative effect on cancer. However, the informants appreciated the effects they experienced on symptoms such as insomnia, anxiety, nausea, and pain.²⁶

To our knowledge, no studies have reported patients’ perceived effects of cannabis, whether curative or symptom-relieving, in the general population of patients receiving palliative care. In addition, we did not find any European studies that reported patient perception and experience regarding cannabis consumption within the same population.

The aim of this survey was to assess the perception and consumption of cannabis for medical purpose among Danish patients with end-stage cancer receiving palliative care.

Methods

A cross-sectional perception survey, stratified by cannabis consumption history, was conducted among patients with cancer at the palliative care unit (PCU) of North Denmark Regional Hospital between June 2019 and January 2021.

Survey design

The perception survey comprised three different questionnaires to encompass three subgroups of respondents based on their cannabis consumption history. The subgroups were experienced respondents, either a) current consumers (who were consuming cannabis at the time of completing the questionnaire) or b) prior consumers (who had consumed cannabis at any time in the past) and c) naïve respondents (who had never consumed cannabis). Each questionnaire had a specific set of items, focusing on five themes: 1) demographic and clinical characteristics, 2) background information related to cannabis 3) perception of cannabis for medical purposes, 4) key aspects of cannabis consumption, and 5) the treatment outcomes experienced by the patient. Themes 1, 2, 4, and 5 included multiple-choice questions, and an option for “Other” with the possibility for free text responses. Theme 3 used a four-point Likert scale (Strongly disagree, Disagree, Agree, and Strongly agree) and an option for “Do not know” (Table 1).

Table 1.

Content of Questionnaire Survey among Respondents Divided into Three Groups according to History of Cannabis Consumption

	Experienced respondents
Themes and items	Current consumers	Prior consumers	Naïve respondents
Number of items	17	16	13
Demographic and clinical characteristics
Age	x	x	x
Gender^a	x	x	x
Cancer diagnosis^a	x	x	x
Time since cancer diagnosis^a	x	x	x
Educational level^a	x	x	x
Background information related to cannabis
Dialogue with Health Care Professional (HCP)^a	x	x	x
Which HCP^a	x	x	x
Preferred access to cannabis^a	x	x	x
Reasons for not consuming cannabis^a			x
Perception of cannabis for medical purposes
Relief of cancer-related symptoms^b	x	x	x
Curative effect of cannabis on cancer^b	x	x	x
Key elements in cannabis consumption
Sources of interest in consuming cannabis^a	x	x
Means of access to cannabis^a	x	x
Form/route of administration^a	x	x
Preferred form/route of administration^a			x
Frequency of consumption^a	x	x
Reasons for consumption^a	x
Reasons for discontinuation^a		x
Treatment outcomes
Patient-reported effect^a	x
Anticipated effect^a			x
Patient reported adverse reactions^a	x	x

Multiple choice.

Likert 4-point scale (Strongly disagree, Disagree, Agree, and Strongly agree) and “Do not know”.

The survey items were developed specifically for this study, drawing insights from a previous qualitative interview study involving 20 patients receiving palliative care for cancer. The interview findings highlighted key themes, such as the patients desires to survive cancer, their sense of hope, the aspects of their experiences, and their perceptions of cannabis, including its effects.²⁶ The wording used by the informants in the interviews was incorporated into the survey items. Two statements were constructed based on the interview findings. The first statement, “Cannabis relieves symptoms” emerged as a common theme among the interviewees. They expressed their belief that cannabis had the potential to alleviate various symptoms. The second statement, “Cannabis has a curative effect on cancer,” reflected another recurring theme in the interviews, despite variations in the informants understanding of the extent and nature of this believed effect.

The items underwent interactive testing involving the research team, an independent health care professional, and staff from the PCU. The feedback from each session was used to refine the questionnaire. Finally, the items were pilot-tested by four patients with end-stage cancer who received palliative care. The researcher encouraged the patients to comment on the clarity and relevance of the questions, whereas an observer paid attention to the time spent, the flow of filling in the questionnaire, and any items that the respondents found difficult to answer. Subsequently, the survey items were revised and finalized, resulting in three short and simple questionnaires (13–17 items) tailored to the three subgroups.²⁷

Respondents

Patients who received home visits from the PCU were consecutively screened for participation. The eligibility criteria included patients with cancer aged ≥18 years old and able to understand and complete a questionnaire. Patients who agreed to participate received an additional home visit from the research team, during which they were once again informed about the study and provided written informed consent. The research team provided three paper survey versions and selected the appropriate one for each respondent based on their actual cannabis history responses. In addition, the research team was able to assist the respondents with the questionnaire, including reading the questions aloud or turning pages. If respondents had questions about cannabis or treatment, they were answered after the survey to avoid influencing their responses

As the survey was not conducted anonymously, the respondents were assured that any information collected in the study was kept strictly confidential and neither used nor reported to the PCU staff.

Ethics and data protection

The study protocol was reviewed by the Ethics Committee of the North Denmark Region, who determined that no further ethical approval was required according to Danish law.

The study was registered with the regional legal services (North Denmark Region 2019-90) who also reviewed and approved the survey cover letter and the informed consent form.

The study was conducted in accordance with the Declaration of Helsinki, and the data handling and processing were compliant with the EU General Data Protection Regulation.

Data management and statistics

Data were entered into the Research Electronic Data Capture (REDCap)²⁸ and exported for analysis, statistics, and visualization using R version 4.0.3.²⁹ Descriptive statistics, including univariate tables, were summarized with median (IQR) and the Kruskal–Wallis test (with two groups applying the Wilcoxon signed-rank test), and categorical variables were summarized as percentages using the chi-square test or Fisher’s exact test.

Data on a Likert scale were grouped into categories: either agree/strongly agree, disagree/strongly disagree, or “Do not know.”

Results

Among 239 eligible patients, 160 (67%) provided written informed consent and answered the survey. Data from all respondents were included in the analysis. The median age was 73 years (range 19–96) and 54% of the respondents were female. The three most prevalent cancer locations were the lungs (24%), prostate (14%), and pancreas (11%) (Table 2).

Table 2.

Demographic and Clinical Characteristics of Respondents in the Questionnaire Survey

		Experienced respondents
	Total	Current consumers	Prior consumers	Naïve respondents
Characteristics	n = 160 n (%)	n = 17 n (%)	n = 22 n (%)	n = 121 n (%)	p value
Gender, n (%)					0,657
Male	73 (46)	6 (35)	10 (45)	57 (47)
Female	87 (54)	11 (65)	12 (55)	64 (53)
Median age, years (IQR)	73 (64–78)	74 (59–78)	66.5 (58–71)	74 (66–80)	<0.01
Cancer diagnoses^a, n (%)					0.623^b
Lung	38 (24)	6 (35)	5 (23)	27 (22)
Prostate	23 (14)	0 (0)	3 (14)	20 (16)
Pancreas	18 (11)	1 (6)	4 (18)	13 (10)
Colon/rectum	17 (11)	2 (12)	1 (5)	14 (11)
Stomach/esophagus	16 (10)	0 (0)	3 (14)	13 (10)
Breast	12 (8)	2 (12)	1 (5)	9 (7)
Gynecological	11 (7)	3 (18)	2 (9)	6 (5)
Kidney/bladder	10 (6)	1 (6)	1 (5)	8 (7)
Other^c	18 (11)	2 (12)	2 (9)	14 (11)
Time since cancer diagnosis, n (%)					0.737
<12 months	62 (39)	8 (47)	9 (41)	45 (38)
≥12 months	97 (61)	9 (53)	13 (59)	75 (62)
Not reported	1	0	0	1
Educational level ^d, n (%)					0.611
Low	72 (45)	6 (35)	12 (55)	54 (45)
Medium	45 (28)	7 (41)	4 (18)	34 (28)
High	43 (27)	4 (24)	6 (27)	33 (27)

Three patients reported two cancer diagnoses.

Fisher’s exact test.

Other cancer diagnoses (n = 18) were cancer of the bone and soft tissue (n = 5), head and neck (n = 5), brain (n = 2), blood and lymph system (n = 2), melanoma (n = 2), myelomatosis (n = 1), unknown (n = 1), and male genitals (n = 0).

Categories based on the International Standard Classification of Education (ISCED): Low level 1–2, medium level 3–5, and high level 6–8.

IQR, interquartile range.

Most respondents, 121 (76%), were naïve to cannabis and the remaining 39 (24%) were experienced respondents, either current (n = 17) or prior consumers (n = 22).

Perception of cannabis effect

Respondents reported their level of agreement with two statements. Regarding perception of the first statement, “Cannabis relieves symptoms” agreement or strong agreement was reported by 16/17 (94%) and 18/22 (82%) of the current and prior consumers, respectively, versus 74/121 (61%) of the naïve respondents (p = 0.056) (Fig. 1).

FIG. 1.

Participants’ perception of the statement on the effect of cannabis for symptom relief: “Cannabis relieves symptoms”.

Regarding the second statement, “Cannabis has a curative effect on cancer” experienced respondents were more likely to agree than naïve respondents (p < 0.01) (Fig. 2). Agreement or strong agreement with the statement was reported by 10/17 (59%) and 10/22 (45%) current and prior consumers, respectively, versus 26/121 (21%) of naïve respondents.

FIG. 2.

Participants’ perception of the statement on the effect of cannabis as an anticancer drug: “Cannabis has a curative effect on cancer”.

Experienced respondents

Family or friends were reported as the primary source of interest in cannabis by 28/39 (72%) of the experienced respondents (Table 3). Two respondents identified health care professionals (HCP) as their source of interest in consuming cannabis. In addition, 25 respondents claimed to have discussed cannabis consumption with an HCP at some point, with 19 being the staff at the PCU. In both subgroups of experienced respondents, 82% reported a preference for cannabis on prescription, whereas 18% preferred unauthorized cannabis. However, the actual percentage of prior consumers who obtained cannabis on prescription was only 1/22 (5%), compared with 11/17 (65%) of the current consumers (p < 0.01). The most common form was oil in both subgroups (Table 3).

Table 3.

Interest in, Access to, and Route of Administration of Cannabis

	Total	Current consumers	Prior consumers
Information on cannabis use	n = 39 n (%)	n = 17 n (%)	n = 22 n (%)	p value
Sources of interest in consuming cannabis^a
Family or friends	28 (72)	12 (71)	16 (73)	1.00
Media^b	11 (28)	4 (24)	7 (32)	0.83
Health care professionals (HCP)	2 (5)	1 (6)	1 (5)	1.00
Other patients	1 (3)	1 (6)	0 (0)	0.90
Other	3 (8)	1 (6)	2 (9)	0.83
Access to cannabis ^a
Prescription by a physician	12^c (31)	11^c (65)	1 (5)	<0.01
Unauthorized	28^c (72)	8^c (47)	20 (91)	<0.01
Not reported	1 (3)	0	1 (5)
Form/administration of cannabis^a
Oil	31 (79)	13 (76)	18 (82)	0.99
Paste	3 (8)	2 (12)	1 (5)	0.82
Tablet	3 (8)	1 (6)	2 (9)	1.00
Capsule	3 (8)	2 (12)	1 (5)	0.82
Smoking	3 (8)	2 (12)	1 (5)	0.82
Other^d	2 (5)	0 (0)	2 (9)	0.59

	Total	Current consumers	Prior consumers
None	22 (56)	10 (59)	12 (55)	0.79
Fatigue	6 (15)	3 (18)	3 (14)	1.00
Euphoria	5 (13)	3 (18)	2 (9)	0.76
Xerostomia	4 (10)	2 (12)	2 (9)	1.00
Other^b	10 (26)	5 (29)	5 (23)	1.00

Naïve respondents

Among the 121 naïve respondents, 34 (28%) reported that they had discussed optional cannabis with an HCP, with 24 being the staff at the PCU. Twenty respondents reported direct reasons for not consuming cannabis: 9 cited physicians as the reason and 11 reported it was their own decision (cannabis perceived harmful, too expensive, or they simply did not want it). The rest provided insignificant reasons. At the time of the survey, 12 respondents (10%) were considering cannabis consumption.

Pain was the most common symptom for which cannabis medicine was considered a treatment option (74%, n = 89). The majority (98%) of naïve respondents would prefer cannabis prescribed by a physician, and the preferred form was oral oil (54%, n = 65), followed by tablets (35%, n = 42) or capsules (14%, n = 17).

Discussion

The present study was prompted by the initiation of the Medicinal Cannabis Pilot Program in Denmark, highlighting the need to explore patient perceptions and experiences regarding medicinal cannabis. To our knowledge, this is the first study to investigate cannabis consumption for medical purposes in patients with end-stage cancer receiving palliative care in the European population.

The findings of our study indicate that one-quarter of patients in palliative care had some experience with cannabis consumption, either currently or in the past. This prevalence aligns with international studies conducted in countries such as Canada, the USA, Australia, Denmark, and Israel, where patients with cancer have reported consuming cannabis to enhance their overall well-being by addressing distressing symptoms.^{17–20,22–25} Although many studies have explored the symptomatic benefits of cannabis consumption in patients with cancer, our research aimed to contribute to the knowledge of the psychosocial aspects of cannabis in the context of palliative care. Cannabis-naïve patients, who lack direct exposure to cannabis, provide a distinctive perspective on the expectations and misconceptions associated with cannabis.

A substantial proportion of respondents in our study perceived cannabis as a symptom relieving product. Interestingly, this perception of cannabis was reported by current cannabis consumers, as well as prior consumers and naïve respondents.

The most common reasons for cannabis consumption were pain, appetite loss, and fatigue. Patient-reported effects, including pain relief, relaxation, improved sleep, and better mood, were consistent with the symptom-relieving properties of cannabis noted in previous studies.^{16,21,22,24,25}

It is essential to note that nearly half of the experienced respondents in this study reported adverse reactions, such as fatigue, euphoria, and xerostomia, and one-fifth of the prior consumers discontinued cannabis due to adverse reactions. However, symptoms related to cancer and previous anticancer treatment can be difficult to distinguish from adverse reactions related to cannabis, which underscores the importance of medical expertise and the informed use of cannabis medicine, especially in vulnerable populations such as patients in palliative care.

One noteworthy aspect of our study is the observation that patients with experience of cannabis consumption were more likely to agree with the statement that “Cannabis has a curative effect on cancer” compared with those who were cannabis naïve. This perception, which was not well defined among the respondents, reflects a recurrent theme identified in qualitative interviews: a belief in the potential curative impact of cannabis on cancer and a desire among patients for a more active role in exploring alternative treatment options.²⁶ This finding suggests that patients may harbor a sense of hope and optimism regarding the therapeutic potential of cannabis in the context of their terminal illness.

It is plausible that, despite the belief in the potential effects of cannabis, patients may face barriers in translating this belief into action. Several factors may have contributed to this phenomenon. First, the legal and regulatory framework surrounding medicinal cannabis, as implemented through programs such as the Medicinal Cannabis Pilot Program in Denmark, may pose challenges for patients with end-stage cancer to access cannabis as a treatment option. The intricacies of obtaining prescriptions and the limited availability of medicinal cannabis products may hinder patients from actively pursuing cannabis treatment, even if they strongly believe in its potential efficacy.

Moreover, the discrepancy between beliefs and actions could be influenced by a lack of clear clinical guidance and physician support for cannabis medicine. The hesitancy of physicians to prescribe and counsel patients on cannabis medicine, as echoed in existing literature, may contribute to a disconnect between patient beliefs and the proactive pursuit of cannabis as a complementary therapy.^30–32

The origin of interest in cannabis among experienced respondents predominantly stems from family or friends, and one-third claimed that they had not discussed their cannabis consumption with HCP. This highlights the gap in communication between patients and health care providers.

Our study has several limitations including its reliance on self-reported data, which may be subject to recall bias, and the items constructed for this specific perception survey with less well-defined perceptions and definitions.

The survey was also constrained by the limited number of respondents, who had consumed cannabis, either currently or in the past. Hence, the danger of type II error is evident. As this study was descriptive in nature, the rejection of differences between naïve and experienced respondents based on statistical tests was not within the scope of this study. Approximately one-third of the eligible patients declined or canceled visits, which could be attributed to clinical instability or the COVID-19 pandemic. The pandemic caused a national lockdown, resulting in the postponement of study visits and patients avoiding unnecessary visits.

In addition, this study focused on a specific region of Denmark, which limits the generalizability of the findings to a broader population.

However, this study sheds light on the perceptions and experiences of Danish patients with end-stage cancer receiving palliative care regarding cannabis consumption. These findings underscore the need for improved communication between patients and physicians, as well as the importance of addressing the potential therapeutic benefits and risks associated with cannabis consumption in this population. Strategies for communication between physicians and adults with cancer about the use of cannabis have been provided in the recently issued clinical guidelines by the American Society of Clinical Oncology.³³ The same guidelines also highlight the critical need for more cannabis research to guide HCP in supporting patients with end-stage cancer in symptom management and improving QoL.

The distinction between symptom relief and patients’ beliefs is crucial, as it reflects the multifaceted nature of patient experience. Our study sheds light on the complexity of decision making regarding cannabis medicine, driven not only by the desire for symptom relief but also by patients’ perceptions, hopes, and potentially, misconceptions about the role of cannabis in the context of their terminal illness. As cannabis continues to be explored as a complementary therapy, understanding these subjective aspects is essential for providing patient-centered care and facilitating open and informed discussions between health care providers and patients.

Conclusions

Majority of the respondents in this study believed that cannabis has a symptom-relieving effect, and one-quarter of the respondents reported a history of cannabis consumption, either currently or in the past. The findings of the survey also suggest that patients may harbor a sense of hope and optimism regarding the believed curative aspect of cannabis in the context of terminal cancer illness. This underscores the need for improved communication between patients and health care providers, as well as the importance of addressing the potential therapeutic benefits and risks associated with cannabis consumption in patients with end-stage cancer.

Footnotes

Acknowledgments

The authors are grateful to the patients who participated in the study. The authors sincerely thank Kristina Winter, PCU, for her support and interest.

Data Access Statement

The participants of this study did not consent to their data to be shared publicly, so due to the sensitive nature of the research supporting data is not available.

Authors’ Contribution

D.B.: Conceptualization, methodology, validation, formal analysis, data curation, writing original draft, writing review and editing, and project administration. D.B.: Conceptualization, methodology, validation, investigation, resources, writing—review and editing, and project administration. D.B.: Methodology, software, investigation, and writing—review and editing. K.L.H.: Conceptualization, methodology, writing—review and editing, and funding acquisition. D.M.: Conceptualization, methodology, validation, and writing—review and editing. S.W.N.: Conceptualization, methodology, and writing—review and editing. P.L.: Conceptualization, methodology, validation, resources, writing—original draft, writing—review and editing, supervision, and funding acquisition.

Author Disclosure Statement

The authors declare that there is no conflict of interest.

Funding Information

The author(s) disclose receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Danish Cancer Society [Grant No. R224-A13527].

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	Total	Current consumers	Prior consumers
Reported adverse reactions^a	n = 39 n (%)	n = 17 n (%)	n = 22 n (%)	p value
None	22 (56)	10 (59)	12 (55)	0.79
Fatigue	6 (15)	3 (18)	3 (14)	1.00
Euphoria	5 (13)	3 (18)	2 (9)	0.76
Xerostomia	4 (10)	2 (12)	2 (9)	1.00
Other^b	10 (26)	5 (29)	5 (23)	1.00