Cannabis Use in Patients with Head and Neck Cancer and Radiotherapy Outcomes

Abstract

<h3>Purpose/Objective(s)</h3> Marijuana use in the population is increasing as states continue to allow for both medicinal and recreational use. As such, the prevalence of marijuana use among patients presenting for treatment of head and neck cancer (HNC) is likely to increase as well. Anecdotally, patients are asking about marijuana use during cancer treatment and, to date, oncology professionals treating HNC are lacking sufficient data to aid in advising their patients on use during cancer care. Further, the impact of marijuana use on survival and local control in HNC is not well understood. The current study examines the associations between marijuana use and the management and outcomes in patients with HNC squamous cell carcinoma. <h3>Materials/Methods</h3> IRB approval was obtained for a retrospective evaluation in our institutional database. Two-hundred eighty patients with detailed psychosocial and substance abuse history who were treated with either definitive or adjuvant radiotherapy between August 2018 and March 2020 were included in the analyses. Overall survival (OS) and disease-free survival (DFS) were compared between current marijuana users and non-users using Kaplan-Meier curves and log-rank tests. <h3>Results</h3> 148 patients with HNC were included (mean age=62.1 yrs, SD=9.1), 78% were male, 73% were white, 22% were black. 62% of patients had SCCa of the oropharynx, 20% SCCa of the larynx, and 14% SCCa of the oral cavity. 51% were treated with definitive chemoradiotherapy, while 32% had primary surgery. 30% were current tobacco users and 70% had ever used tobacco (mean = 43.33 PY). 15% of patients reported marijuana use at time of initial diagnosis and 34% reported a history of marijuana use. Older patients and males were more likely to be currently using marijuana (p=.005 & p=.04, respectively). Current marijuana users were more likely to require narcotic pain medications and require a greater number of types of pain medications during treatment (p=0.002 and p=0.007, respectively). There were no differences between current and historical/never users on self-reported worst pain, weight loss or enteral feeding tube use during treatment, or objective measures of treatment toxicity. Additionally, there were no other significant differences between current or historical/never users were found on cancer variables or primary treatment type. <h3>Conclusion</h3> Marijuana use in patients with HNSCCa is common and little is known about patient and oncological outcomes. There were no significant differences between current and past marijuana users and non-users on clinicopathological variables, adherence, or oncologic outcomes. Marijuana use in HNC may result in more difficulty managing pain during treatment. Further research is needed to better understand marijuana use during cancer treatment, particularly frequency and method of use (i.e., smoking vs. edibles/oils), outcomes, and quality of life.