Concerns about Cannabis and Cancer-related Immunotherapies

Some recent clinical observational studies have suggested that the co-administration of cannabinoid-based therapeutics and immunotherapy or immune checkpoint inhibitors in the treatment of certain types of cancer has been associated with worse overall survival rates (T. Taha et al., 2019; A. Biedny et al., 2020; G. Bar-Sela et al., 2020).

 

However, one trial conducted on animals resulted in data suggesting that cannabis did not negatively affect the properties of immune checkpoint inhibitors (B. Waissengrin et al., 2023). The authors compared the previous study results with findings from a cohort of 201 patients with metastatic non-small cell lung cancer who received monotherapy pembrolizumab as a first-line treatment and adjunct cannabis to treat mainly pain and loss of appetite. Their time to tumor progression was 6.1 versus 5.6 months, and overall survival differed between 54.9 versus 23.6 months in cannabis-naïve patients and cannabis-using patients, respectively. However, while numerically different, the authors write that these differences were not statistically significant, leading them to suggest that “These data provide reassurance regarding the absence of a deleterious effect of cannabis in this clinical setting.”