Oncology Fellows' Clinical Discussions, Perceived Knowledge, and Formal Training Regarding Medical Cannabis Use: A National Survey Study

Abstract

PURPOSE:

Evidence suggests that patients with cancer frequently use cannabis with medicinal intent and desire clinical guidance from providers. We aimed to determine whether oncology training adequately prepares fellows to discuss medical cannabis.

METHODS:

A national survey study was conducted from January to March 2021. A questionnaire assessing oncology fellows' practices regarding cannabis recommendations in cancer care and their knowledge of its effectiveness and risks compared with conventional care for cancer-related symptoms was developed and sent to 155 US-based oncology training programs to distribute to trainees.

RESULTS:

Forty programs from 25 states participated; of the 462 trainees across these programs, 189 responded (response rate of 40%). Of the participants, 52% were female; 52% were White, 33% Asian, and 5% Hispanic. Fifty-seven percent reported that they discussed medical cannabis with more than five patients in the preceding year; however, only 13% felt sufficiently informed to issue cannabis-related clinical recommendations. Twenty-four percent reported having received formal training regarding medical cannabis. Oncology fellows who reported having received prior training in medical cannabis were significantly more likely to discuss cannabis with patients (risk ratio: 1.37, 95% CI 1.06 to 1.75; P = .002) and feel sufficiently informed to discuss cannabis recommendations (risk ratio: 5.06; 95% CI, 2.33 to 10.99; P < .001). Many viewed the botanical as a useful adjunctive therapy that was at least as effective as conventional treatments for anorexia/cachexia (72%), nausea/vomiting (45%), and pain (41%).

CONCLUSION:

Most oncology trainees not only reported engaging in discussions regarding medical cannabis with patients but also considered themselves insufficiently informed to make cannabis-related clinical recommendations. The discrepancy between the frequency of cannabis inquiries/discussions at the patient level and comfort/knowledge at the trainee provider level represents an unmet curricular need with implications for both graduate medical education and patient care.

BACKGROUND

In the United States, use of medical cannabis remains federally illegal; however, 38 states and the District of Columbia have enacted laws to allow for its use at the local level. Among these state laws, cancer is one of the two most frequent qualifying conditions for medical cannabis.¹ With cannabis' increasing availability and legalization (for medical and adult-use purposes), interest in and use of cannabis among patients is widely prevalent.^2,3 Indeed, one in four patients with cancer has been reported to use cannabis with therapeutic intent.² Patients with cancer demonstrate high levels of interest in learning about cannabis use in their care, and the majority seek to obtain information about its use from their cancer care providers.² Previous studies of oncology providers have shown that although most medical oncologists discuss cannabis with patients and their families, very few feel sufficiently informed to make recommendations.^4,5 Consequently, patients with cancer who use medical cannabis report minimal medical oversight of their cannabis use by their oncology providers.⁶

Physicians currently enrolled in oncology training programs are the future workforce who will care for an increasing number of patients with cancer.⁷ We conducted a national survey of trainees enrolled in oncology training programs to determine the extent of their clinical discussions regarding medical cannabis, the medical cannabis training that they receive, and whether they considered themselves adequately informed to make recommendations on its use. We hypothesized that they have received little formal medical cannabis training and thus would infrequently discuss its use with their patients stemming from the perception that they are ill-equipped to do so.

METHODS

This was a cross-sectional, online survey study targeting fellows currently enrolled in oncology training programs across the United States. The Institutional Review Board at the Beth Israel Deaconess Medical Center approved this study as exempt from human subjects' research.

Study Population/Recruitment

The survey was distributed anonymously using a web-based platform, REDCap Survey (Research Electronic Data Capture) between January 1, 2021, and March 1, 2021.^8,9 To accomplish this, contact information of program directors (PDs) of all American College of Graduate Medical Education—accredited hematology/oncology fellowship training programs was obtained.¹⁰ The survey was e-mailed to all PDs (n = 155) accompanied by a letter requesting that the survey is forwarded to all fellows in their programs. PDs were asked to confirm their program's participation; if confirmed, PDs provided the number of fellows in their training program to whom the survey would be forwarded. PD responses were kept anonymous. Two reminder e-mails were sent one week apart to PDs. Survey participation was incentivized with $25 in US dollars gift cards assigned by random lottery.

Data Collection

The survey included 30 multiple-choice questions and two open-ended response options. The study instrument was adapted to be appropriate for oncology fellows from a previous national survey developed for practicing oncologists⁴ (Data Supplement, online only). Medical cannabis was explicitly defined by the survey as “non-pharmaceutical cannabis that health care providers recommend for therapeutic purposes.”⁴ The draft instrument was vetted by a multidisciplinary study group with oncology, psycho-oncology, and qualitative methodological expertise; this was piloted on five trainees for clarity, length, and relevance before dissemination.

The survey items most germane to these analyses included the following: (1) frequency of clinical discussions and nature of initiation regarding medical cannabis; (2) perceived knowledge of medical cannabis; (3) perceived comparative effectiveness of medical cannabis as compared with conventional care for cancer-related conditions (vomiting, diarrhea, pain, and mood disorders)—either as a sole or adjunct intervention; (4) perceived comparative risks of medical cannabis as compared with opioids for mood disorders, falls, or cannabis use disorder; and (5) prior training in medical cannabis and source(s) of information. Response categories were grouped (eg, 0-5 patients and 5-20 patients) rather than free-text responses for ease of completion of survey. In addition, the questionnaire asked participants to report their age, sex, ethnicity, medical school (foreign v United States/Canada), year of training, state of training program, stratified by region,¹¹ and patient volume. Participants were asked to complete two open-ended questions: (1) “Please let us know your thoughts on the use of medical cannabis for patients with cancer” and (2) “Please let us know your thoughts on what should be included in a training program for medical cannabis for patients with cancer.”

Outcomes

The number of patients in the preceding year with whom each trainee reported discussing medical cannabis comprised the primary outcome: “In the past year, for approximately how many patients did you discuss cannabis use for cancer-related issues?”. The secondary outcome was whether trainees felt sufficiently informed to make medical cannabis recommendations: “Do you feel you have sufficient knowledge about medicinal use of cannabis to make recommendations for oncology patients?”. For regression analyses, we dichotomized the number of patients for whom trainees discussed cannabis in the past year to 0-5 and > 5.

Analyses

We summarized data as count and proportion. We used log-binomial regression to assess whether the primary outcomes varied by participant gender, age, year of graduation, region of practice, clinical focus of practice, volume of oncology patients seen, or prior training in medical cannabis; we present risks with 95% CIs. We then chose select variables (ie, year of medical school graduation, legal status in state of practice, and having received prior training in medical cannabis) on the basis of subject matter expertise to include in a multivariable adjusted analysis to explore factors that were significantly associated with the primary and secondary outcomes. We considered a two-sided P value of < .05 to be statistically significant. We performed all analyses using SAS, version 9.4 (SAS Institute, Cary, NC) and GraphPad Prism for Windows (GraphPad Software, La Jolla, CA).

To identify themes in participants' responses to open-ended questions, we performed a thematic analysis.^12,13 Two investigators (R.P. and P.B.) read the text responses for the first 15 participants and coded phrases, sentences, or longer segments of text. Codes included deductive codes (determined a priori) and inductive codes that emerged from the text. The research team met to organize codes to reflect major themes. Disagreement about the meaning of themes or codes was resolved by consensus. Once a codebook was established (available in the Data Supplement), the text was coded in detail by two (R.P. and P.B.) investigators. All open-ended responses were reviewed. Direct quotes from the data are used to illustrate themes.

RESULTS

Of the 155 training programs approached, 40 PDs from 25 states in the United States agreed to send the survey to their fellows. Of 462 trainees across these programs, 189 completed the survey, yielding a response rate of 40% (Appendix Fig A1, online only). Among respondents, half (52%) were female; half (52%) were White, 33% Asian, and 5% Hispanic (Table 1). One third graduated from medical school after 2015, and the majority (79%) attended medical school in the United States. Survey participants hailed from training programs across all four census regions of practice; 37% offered clinical care in states with both legalized medical and adult-use cannabis, and 44% practiced in states with legalized medical cannabis only.

TABLE 1.

Participant Characteristics

Fifty-seven percent of participants reported having discussed medical cannabis with more than five patients in the preceding year, and 91% reported discussing medical cannabis with patients at some point in their training. The majority (80%) of participants reported that patients and families usually initiated these conversations. Less than one quarter (24%) of participants reported having received formal training regarding medical cannabis, and only 13% perceived themselves sufficiently knowledgeable about medical cannabis to feel comfortable making clinical recommendations (Appendix Table A1, online only). Among respondents, the most common sources for medical cannabis information were peer-reviewed scholarship (30%), lectures/webinars by colleagues (29%), and patients and their families (22%). After adjusting for year of medical school graduation and legal status in the state of practice, oncology trainees with formal training in medical cannabis were significantly more likely to discuss cannabis with more than five patients in the preceding year compared with those without formal training (risk ratio: 1.48; 95% CI, 1.17 to 1.86; P < .001; Table 2; Appendix Fig A2, online only). None of the other variables in the adjusted model were significantly associated with the number of patients with whom trainees discussed medical cannabis (all P ≥ 0. 27). Prior training in medical cannabis was also associated with increased rates of feeling sufficiently informed about medical cannabis use (risk ratio: 5.06; 95% CI, 2.33 to 10.99; Appendix Table A2, online only). Formal training was not associated with time since medical school graduation, with 27.4% of respondents who graduated before 2015 reporting having received formal training compared with 22.1% of those who graduated in 2015 or later (P = 0.43).

TABLE 2.

Factors Associated With Discussing Medical Cannabis With More Than Five Patients in the Past Year

Most participants regarded cannabis as equally effective as or less effective than standard treatments for cancer-related symptoms such as nausea/emesis, pain, mood, sleep, and anxiety (Fig 1A; Appendix Table A3, online only). However, 54% reported cannabis to be at least somewhat more effective than conventional therapies for anorexia or cancer cachexia. The majority of participants believed that medical cannabis could be a useful adjunct for cancer-related anxiety (78%) and pain (80%). When comparing medical cannabis use with opioid use, participants viewed medical cannabis as more likely to trigger paranoia or psychosis (40%) and lung injury (59%); opioid use was deemed more likely to result in anxiety (40%), depression (47%), confusion (60%), and falls (55%; Fig 1B; Appendix Table A4, online only). In addition, 39% of participants were at least somewhat concerned about the increased risk of infections with combusted medical cannabis used by immunocompromised oncology patients.

FIG 1.

(A) Trainees' views on comparative side effects of cannabis compared with opioids. Blue represents the percentage of trainees who viewed the side effects of medical cannabis to be comparable, somewhat higher, or much higher compared with opioids for the listed symptoms. Red represents the trainees who viewed the comparative side effects to be somewhat lower or much lower than opioids. Teal represents the trainees who reported that they did not know about comparative side effect frequency of medical cannabis and opioids. (B) Trainees' views on effectiveness of medical cannabis as compared with conventional therapies for symptom management. Blue represents the percentage of trainees who viewed medical cannabis to be equally effective, somewhat more effective, or much more effective compared with conventional treatments for the listed symptoms. Red represents the percentage of trainees who viewed medical cannabis to be somewhat less effective or much less effective compared with conventional treatments. Teal represents the trainees who did not know about the comparative effectiveness of medical cannabis and conventional treatments for listed indications.

Table 3 presents the major themes in participants' open-ended responses. In general, participants had mixed opinions about the usefulness of cannabis in oncology populations (eg, respondent #140: “I think it is a useful, potent, and very helpful adjunct for patients with few side effects, especially compared to the standard of care medications we give”). Several identified barriers to its use, including lack of strong clinical data, dearth of training, stigma associated with its use, and regulatory policies at the institutional/state/federal levels (eg, respondent #117: “The lack of solid data with well-designed trials is frustrating, especially given the heavy commercial interests and pop culture influence”). Participants offered many suggestions as to what should be included in a curriculum on medical cannabis for oncologic care, including indications for use, adverse events, formulations and routes of administration, prescribing and dosage information, and regulatory aspects regarding its use in medicine (Appendix Table A5, online only).

TABLE 3.

Themes Captured in Free-Text Response and Representative Quotes (n = 130 Participants Responded to an Open-Ended Question)

DISCUSSION

To our knowledge, the clinical attitudes, practices, training, and self-reported knowledge of oncology trainees regarding medical cannabis have not previously been evaluated—although prior publications indicate that it is a common area of interest for oncology patients. Although more than half of all oncology fellows surveyed (n = 189) had engaged in clinical discussions with more than five patients on this matter during the preceding year, only 12.8% felt that they possessed sufficient knowledge to make clinical recommendations regarding cannabis use in their patients. Furthermore, less than one quarter reported having received any formal medical cannabis training. Of note, trainees who had received previous formal medical cannabis training were both significantly more likely to address cannabis use with their patients and five times more likely to consider themselves sufficiently informed to advise their patients regarding its use. Although few had been formally trained in medical cannabis use, most indicated confidence in its medicinal potential—including a prevalent belief that it is more effective than standard treatments for cancer-related anorexia/cachexia and may be a useful adjunct to standard treatments for cancer-related anxiety and pain. With estimates of up to 25% of individuals with cancer using cannabis largely for medicinal purposes, this study identifies a substantial gap between patients' needs and practices and providers' knowledge, attitudes, and behaviors.

Our results extend those of a few national surveys of oncologists (in the United States,⁴ Italy,⁵ and Israel¹⁴) that have highlighted the reality that many oncology providers are conducting clinical discussions regarding medical cannabis even as they feel themselves ill-equipped to do so. Although oncology trainees have a more confined and supervised scope of practice in oncology, they represent an important fraction of the current and future health care workforce engaged in the care of oncology patients. Similar to surveys conducted in practicing oncology attendings,^4,5,14 trainee oncologists in this study reported that discussions around medical cannabis occurred relatively frequently in their clinical practice, even as their self-perceived knowledge was inadequate. Moreover, we found that although only about one fourth of the nationally representative cohort of trainees in this study reported having receiving prior training in medical cannabis, this was the only factor that was associated with both a higher likelihood of having patient-level discussions regarding medical cannabis use and self-perceived preparedness to do so.

Physicians enrolled in oncology subspecialty training programs are the future caregivers for a growing number of patients with cancer. As oncology trainees are enrolled in structured training programs with emphasis on competency-based training, opportunities exist to create curricula to educate them on the role of cannabis in the care of patients with cancer. There is a striking discrepancy between increasing legalization of medical cannabis use and the dearth of professional education efforts at all levels of medical training, including undergraduate, graduate, and postgraduate/continuing medical education.^15-17 Our data provide justification to develop such curricula as part of the training experience for oncology trainees. On the basis of the trainees' self-identified desired learning points in this survey, we propose that key domains to be covered in such curricula include pharmacology of cannabis, data regarding its known efficacy and adverse effects, and logistics and legalities surrounding its use. Challenges include the relative lack of randomized data (which may preclude the ability to make rigorous evidence-based clinical recommendations), a rapidly changing landscape with many emergent and ongoing studies, and the need to tailor the curricula for trainees in different geographic locations on the basis of variable local/national/international regulations.

There are several potential weaknesses of this study. As with most online survey studies, the self-reported nature of responses might have introduced bias.¹⁸ To optimize response rates, all accredited US hematology/oncology fellowship training programs were contacted and surveys were incentivized. A response rate of 40% compares favorably with other similar survey studies among oncology providers.¹⁹ In comparing the demographics of this study's respondents with published information on the current oncology trainee workforce in the United States, the sample of respondents appears to be representative. Moreover, on the basis of the estimated number of trainees in oncology programs in 2019-2020 (n = 1,784), this study captured approximately 11% of the total population.²⁰ Even in states with restrictive cannabis regulation, patients with cancer have been shown to use cannabinoids in various forms.²¹ Given the significant stigma surrounding cannabis use, it is possible that programs—particularly in states where medical cannabis use is not legal—were less likely to circulate the survey and/or trainees might have been less likely to complete them. Recognizing this, survey responses were anonymized, and this was emphasized in the instructions given to potential respondents. Notably, respondents included trainees from 25 states—including five where medical cannabis use is currently not legal (Wisconsin, Texas, Georgia, Tennessee, and Indiana). Moreover, the legal status of cannabis use in the state of location of training program did not significantly affect rates of discussing medical cannabis with oncology patients or self-perceived adequacy of knowledge around medical cannabis in oncology practice. As PDs were the primary advocates for trainee participation, it is possible that this led to a selection bias toward programs that would be more likely to include formal teaching about medical cannabis in their programs. Thus, the rates of formal education around medical cannabis use could be inflated in the sampled cohort. Although it is possible given the more recent upsurge in medical use of cannabis that more recent graduates from medical school are more likely to be exposed to formal training, however, as expected, the respondents in the survey were all relatively close in terms of medical school graduation and this may be why it was not associated with the primary or secondary outcomes in the regression models. Finally, it is important to note that although the survey was designed to capture attitudes and practices, the underlying reasons or motivations could not be explored given the structured survey design. As previously noted and to increase the opportunity for more nuanced responses, the study instrument did include two sections for free-text responses; these were subsequently analyzed thematically.

In this national survey study of trainees from more than 40 US hematology/oncology training programs from 25 US states, we have reported current practices and attitudes among oncology trainees regarding medical cannabis use in oncology patients. Although the majority of respondents reported discussing medical cannabis with patients and their families, formal training around medical cannabis was lacking, and only 12.8% felt that they were adequately knowledgeable on the subject. With the potential for even greater interest in cannabis use from patients with cancer stemming from increasing liberalization of state-level cannabis legislation and decreasing societal stigma, oncologists will need the confidence and knowledge to engage more regularly and meaningfully with their patients regarding existing evidence about medical cannabis use and its potential risks/benefits. We have demonstrated here that formal training on this subject is associated with a higher frequency of discussions regarding medical cannabis and self-perceived adequacy of knowledge to engage in clinical decision making. Our findings suggest that targeted curricula will allow oncology trainees to obtain the knowledge and abilities to best meet the needs of those under their care.

APPENDIX

FIG A1.

Study participation flow. PDs, program directors.

FIG A2.

Factors associated with discussing medical cannabis with more than five patients in the past year. CBD, Cannbidiol; RR, risk ratio; THC, Tetrahydrocannabinol.

TABLE A1.

Practices Around Medical Cannabis

TABLE A2.

Factors Associated With Feeling Sufficiently Informed About Medical Cannabis Use

TABLE A3.

Comparison of Effectiveness of Medical Cannabis With Conventional Treatments

TABLE A4.

Comparison of Side Effects of Medical Cannabis With Those of Opioids

TABLE A5.

Suggested Topics to Include in Curricula for Medical Cannabis in Oncology

DATA SHARING STATEMENT

Individual participant data that underlie the results reported in this article, after deidentification, will be available 3 months to 5 years from publication to researchers who provide a methodologically sound proposal to achieve aims in the approved proposal. Proposals should be directed to rpatell@bidmc.harvard.edu; to gain access, data requestors will need to sign a data access agreement.

AUTHOR CONTRIBUTIONS

Conception and design: Rushad Patell, Poorva Bindal, Laura Dodge, Jason A. Freed, Deepa Rangachari, Mara Schonberg, Ilana Braun

Collection and assembly of data: Rushad Patell, Poorva Bindal, Pavania Elavalakanar, Mary Buss

Data analysis and interpretation: Rushad Patell, Poorva Bindal, Laura Dodge, Mary Buss, Mara Schonberg, Ilana Braun

Manuscript writing: All authors

Final approval of manuscript: All authors

Accountable for all aspects of the work: All authors

AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST

Oncology Fellows' Clinical Discussions, Perceived Knowledge, and Formal Training Regarding Medical Cannabis Use: A National Survey Study

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