The Efficacy of Medical Marijuana in the Treatment of Cancer-Related Pain

Background: The opioid epidemic has spurred investigations for nonopioid options, yet limited research persists on medical marijuana's (MMJ) efficacy in managing cancer-related symptoms. Objective: We sought to characterize MMJ's role on symptomatic relief and opioid consumption in the oncologic population. Design: Retrospective chart review of MMJ-certified oncology patients was performed. Divided patients into MMJ use [MMJ(+)] versus no use [MMJ(-)], and Edmonton Symptom Assessment System (ESAS)-reported pain cohorts: "mild-moderate" versus "severe." Measurements: Medical records were reviewed for ESAS, to measure physical and emotional symptoms, and opiate consumption, converted into morphine milligram equivalents (MME). Minimal clinically important differences were determined. Wilcoxon signed-rank tests determined statistical significance between MMJ-certification and most recent palliative care visit. Results: Identified 232 patients [95/232 MMJ(-); 137/232 MMJ(+)]. Pain, physical and total ESAS significantly improved for total MMJ(-) and MMJ(+); however, only MMJ(+) significantly improved emotional ESAS. MMJ(-) opioid consumption increased by 23% (97.5-120 mg/day MME, p = 0.004), while it remained constant (45-45 mg/day MME, p = 0.522) in MMJ(+). Physical and total ESAS improved in mild-moderate-MMJ(-) and MMJ(+). Pain and emotional symptoms worsened in MMJ(-); while MMJ(+)'s pain remained unchanged and emotional symptoms improved. MMJ(-) opioid consumption increased by 29% (90-126 mg/day MME, p = 0.012); while MMJ(+)'s decreased by 33% (45-30 mg/day MME, p = 0.935). Pain, physical, emotional, and total ESAS scores improved in severe-MMJ(-) and MMJ(+); opioid consumption reduced by 22% in MMJ(-) (135-106 mg/day MME, p = 0.124) and 33% in MMJ(+) (90-60 mg/day MME, p = 0.421). Conclusions: MMJ(+) improved oncology patients' ESAS scores despite opioid dose reductions and should be considered a viable adjuvant therapy for palliative management.