SS 05 - Palliative 1: Faster, Less Toxic, and More Effective: A Holy Trinity in Palliative Radiotherapy
128 - Relationship between Cannabis Use and Opioid Use in Patients with Cancer Metastatic to Bone in a Large Multicenter Cohort from a State with Legalized Adult Non-Medical Cannabis
M. M. Cousins1,2, M. P. Dykstra1, K. Griffith3,4, M. Mietzel3, D. Kendrick3, E. Trumpower3, D. Dusseau5, M. M. Dominello6, M. L. Mierzwa1, E. Covington1, L. J. Pierce1, and J. A. Hayman1; 1Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, 2Department of Radiation Oncology, Self Regional Healthcare, Greenwood, SC, 3Michigan Radiation Oncology Quality Consortium Coordinating Center, Ann Arbor, MI, 4Department of Biostatistics, University of Michigan, Ann Arbor, MI, 5Department of Radiation Oncology, Henry Ford Health System, Jackson, MI, 6Department of Radiation Oncology, Karmanos Cancer Center, Detroit, MI
Purpose/Objective(s): Patients with cancer who use cannabis frequently note pain as a reason for their cannabis use. Available data do support cannabis use for management of pain in some settings, though the effectiveness of cannabis for cancer-associated pain is less clear. Based on limited data, some have suggested that cannabis might be used as an alternative to opiates for management of cancer-related pain. We sought to determine the relationship between cannabis use and opioid use in a multicenter cohort of patients undergoing radiotherapy for bone metastases. Materials/
Methods: On 1/1/2021, questions about cannabis use were added to Michigan Radiation Oncology Quality Consortium (MROQC) questionnaires for bone metastasis patients. Pain scores, opioid use, social, demographic, and disease characteristics were also prospectively collected. A multivariable model using logistic regression identified associations between recent cannabis use and opioid use, accounting for relevant patient and disease characteristics. Results: Since questions on cannabis were introduced, 2,096 patients have been enrolled. A total of 1143/2096 (54.5%) completed questionnaires about recent cannabis use; 1912/2096 (91%) completed questionnaires about current opioid use; and 1064/2096 (51%) completed both. Among those who completed both, 132/1064 (12%) reported recent opioid and cannabis use, 320/1064 (30%) reported recent opioid but not cannabis use, 57/1064 (5%) reported no recent opioid but recent cannabis use, 281/1064 (26%) reported no recent opioid or cannabis use, and the remaining individuals [274/1064 (26%)] declined to answer cannabis use questions by selecting “decline to answer”. In a multivariable model, cannabis use [OR 2.11 (95% CI 1.37, 3.26) p=0.001], along with pain score [Score 1-3 vs 0 OR 2.32 (95% CI 1.36, 3.94); Score 4-7 vs 0 OR 6.55 (95% CI 4.06, 10.6); Score 8-10 vs 0 OR 11.20 (95% CI 6.32, 19.8) p<0.001], NSAID use [OR 1.66 (95% CI 1.17, 2.37) p=0.005], prior systemic therapy [OR 0.54 (95% CI 0.37, 0.78) p=0.005], and number of metastatic lesions [3-5 vs 1-2 OR 1.57 (95% CI 0.95, 2.26); 5-10 vs 1-2 OR 1.54 (95% CI 0.91, 2.59); 11+ vs 1-2 OR 3.26 (95% CI 2.06, 5.15) p<0.001] predicted opiate use while age, gender, and race did not. Conclusion: Patients with bone metastases frequently use cannabis, opioids, or both. Though it has been suggested that cannabis availability might reduce opioid use among patients with cancer, our finding that cannabis use predicts opioid use does not support this hypothesis. These data suggest a more complex relationship between cannabis use and opioid use in this population. Further study is needed to assess risks of concurrent cannabis and opioid use and to explore patient rationale for concurrent usage.
