This study summarizes differences by cancer history in cannabis use patterns, changes in the method of delivery, reports of physical and mental health symptoms managed by cannabis, and COVID-19-related fears among an age-matched sample of respondents from the COVID-19 cannabis health study. Findings from the study suggest that cancer survivors are frequently reporting the use of cannabis to manage both physical and mental health symptoms associated with their cancer diagnosis, which is consistent with studies of cannabis use among cancer survivors before the COVID-19 pandemic [21,22,23,24]. Specifically, self-reported symptoms most frequently managed by medicinal cannabis among respondents included anxiety and pain. While no differences in frequency of cannabis use or method of delivery were observed between those with and without a cancer diagnosis, cancer survivors were more likely to have an advanced supply of cannabis. However, most cancer survivors (77%) reported an advanced supply of less than one month.

Similar to our findings, other studies have also identified anxiety and sleep problems as primary symptoms managed by cancer patients using medicinal cannabis [25,26,27,28].

Opportunities exist for cannabis use as a form of palliative care and non-curative treatment among cancer patients. Early intervention with palliative care among cancer patients can increase overall survival and improve quality of life of both cancer patients and their caregivers [29]. Integrating medicinal cannabis into palliative care can address disparities and underuse of palliative care among cancer patients due to poor effectiveness of current palliative treatment options, as indicated by poor symptom control and intolerable adverse effects attributed to palliative treatment options such as opioids [30]. Anxiety and depression are common mental health symptoms experienced by cancer patients. These mental health symptoms can manifest as worry and poor sleep quality, and about one-third of cancer patients experience psychological distress that requires clinical treatment, although this proportion varies greatly by cancer type and prognosis [31]. As the endocannabinoid system is involved in mood regulation, cannabis-derived treatment could improve mental health symptoms, as has been shown in mice models [32,33]. Curative cancer treatment can also cause physical symptoms such as nausea, vomiting, pain, and neuropathy. Modern antiemetic regimens are less effective at controlling nausea with 40–70% of patients reporting nausea while receiving highly or moderately emetogenic chemotherapy. Chemotherapeutic agents induce nausea and vomiting through elevated release of serotonin which bind to the 5-hydroxytryptmaine 3 (5-HT3)receptors, which send information of excess chemicals to the brain and directly promote emesis [18]. Cannabinoids can directly inhibit these receptors and are thought to act as modulators and indirect agonists on the autoreceptors of the 5-HT3 [34]. The bioactive benefits of cannabis may outweigh its risks, particularly in the context of palliative care. Future research should focus on providing further evidence on the mechanistic pathways and effectiveness to optimize medicinal cannabis applications and dosage.

The COVID-19 pandemic has led to added stress and anxiety among cancer patients [35]. We observed that cancer survivors were more likely to fear a COVID-19 diagnosis compared to those without a history of cancer. Higher levels of fear of contracting COVID-19 among cancer survivors are likely due to both early and more recent reports of increased risk of COVID-19 morbidity and mortality among adults with pre-existing conditions, including cancer [36,37,38,39,40,41,42,43]. To cope with the psychological impacts of the pandemic, cancer patients are exhibiting several coping strategies. For example, US-based ovarian cancer patients reported using emotional support, self-care, hobbies, planning, positing reframing, and religion as coping strategies [44]. Older cancer patients in the US reported to engage in physical activities such as gardening, walking, fitness regimes, tai chi, yoga, and fishing to stay busy or active during the pandemic [45]. Similarly, respondents to our survey reported physical activity as a common coping mechanism. We observed no differences in reported coping strategies by cancer survivor status, which may be explained by the increased use of cannabis for non-medical purposes across the U.S. [46,47].

The results of this study should be considered in light of the limitations of the study. First, due to the cross-sectional nature of the study, causation and temporality cannot be determined. Due to the anonymity of survey responses, there may be repeat responses, although data cleaning and reCAPTCHA methods in REDCap were used to avoid multiple responses. In addition, no monetary or other incentives were provided, thus reducing the likelihood of intentional repeated responses. Generalizability of study findings may be limited due to the electronic nature of the survey, which excludes cannabis users without internet access. Furthermore, due to the self-reported nature of the data, there is potential for recall bias and misclassification bias of COVID-19 and cannabis behaviors and symptoms. Additionally, due to the urgent need for data collection early in the pandemic, the COVID-19 Cannabis Questionnaire was not validated within the target population prior to dissemination in the field. Medicinal cannabis use was based on self-report without medical record or prescription confirmation. Lastly, while differences in the age distribution between cancer survivors and non-cancer survivors were considered in our matching strategy, we describe bivariate associations between cannabis behaviors, COVID-19 symptoms, coping strategies by cancer status, and additional factors including race/ethnicity, gender, and socioeconomic status, which may explain the differences observed in the sample.