Cannabinoids appear to impact immune system function, so could cannabis use blunt the effect of immune checkpoint inhibitors? I don't know, brah. Maybe?
Review: https://pubmed.ncbi.nlm.nih.gov/?term=35749680
Cannabis associated with poorer ORR: https://doi.org/10.1634/theoncologist.2018-0383
Cannabis associated with poorer TTP & OS: https://doi.org/10.3390/cancers12092447