Examining 1-year mortality risk among patients with malignant melanoma undergoing immune checkpoint inhibitor therapy with a history of cannabis use.

Abstract

11046 Background: Cannabis use has become an increased topic of discussion in the United States due to rise in legalization, thereby increasing its accessibility for recreational and medicinal use in diseases like cancer. Immune Checkpoint Inhibitor (ICI) therapy has also recently been increasing in patient with metastatic cancers such as melanoma by targeting PD1 or PD-L1 receptors to manipulate the body’s immune response to induce cancer cell death. Cannabis is mediated in part by the CB1 and CB2 receptors in the endocannabinoid system that is present in the natural immune system. Due to the body’s immune response to cannabis, it is hypothesized this could interfere with the activity of ICI therapy. However, research examining this is sparse. Therefore, the goal was to assess mortality in malignant melanoma patients with a history of cannabis use who undergo ICI therapy. Methods: A retrospective cohort study was performed with TriNetX, a federated database of ~100 million patients across 84 healthcare organizations. Patients >17 years from 2012-2023 were identified based on ICI-therapy initiation within 1 month of malignant melanoma diagnosis. Cohorts were then created by history of those with and without cannabis use disorder. 1:1 propensity score matching was conducted to control for confounding comorbidities and demographics. Unadjusted and adjusted hazard ratios (aHR) with 95% CI were calculated for 1-year mortality after therapy initiation. HR’s were estimated using the Cox proportional hazard model. Survival curves were compared using the log-rank test. Results: A total 14589 melanoma patients who underwent ICI therapy were identified, of which 2.3% had documented cannabis use disorder. Prior to matching, melanoma patients with cannabis history had a statistically significant higher 1-year mortality compared to those with no cannabis history (HR [95%CI] = 1.29 [1.04,1.6], log rank test: p=0.0197). After matching, two balanced cohorts of 344 patients remained and adjusting for confounders revealed that melanoma patients with cannabis history had no significant difference in 1-year mortality risk compared to patients without cannabis history (1.18 [0.87,1.6], log rank test: p=0.293). Conclusions: Cannabis use among melanoma patients was shown to not have any meaningful difference in 1-year mortality risk compared to patients without cannabis use history while undergoing ICI-therapy. Additional studies, such as examining cannabis frequency and dosage, is warranted to further examine its effect.