The role of cancer in marijuana and prescription opioid use in the United States: A population-based analysis from 2005 to 2014

Background: For patients with cancer, marijuana may be an alternative to prescription opioid analgesics. This study analyzed self-reported marijuana and prescription opioid use among people with cancer over a 10-year time period.

Methods: Population-based data sets from the US National Health and Nutrition Examination Survey between 2005 and 2014 were compiled for respondents aged 20 to 60 years. Respondents with cancer and respondents without cancer were propensity score-matched (1:2) by demographics to compare substance use. Outcomes included current marijuana and prescription opioid use (ie, within the past 30 days). Pearson chi-square tests and logistic regressions were performed; a 2-tailed P value < .05 was significant.

Results: There were 19,604 respondents, and 826 people with cancer were matched to 1652 controls. Among the respondents with cancer, 40.3% used marijuana within the past year, and 8.7% used it currently. Respondents with cancer were significantly more likely to use prescription opioids (odds ratio [OR], 2.43; 95% CI, 1.68-3.57; P < .001). Cancer was not associated with current marijuana use in a multivariable conditional logistic regression but was associated with current opioid use (OR, 1.82; 95% CI, 1.17-2.82; P = .008). Among all survey respondents, the odds of marijuana use significantly increased over time (OR, 1.05; 95% CI, 1.01-1.10; P = .012), whereas the odds of opioid use did not significantly change. There were no significant differences in the longitudinal odds of marijuana or opioid use over time between respondents with a cancer diagnosis and those without one.

Conclusions: This population-based analysis revealed a considerable proportion of respondents with cancer self-reporting marijuana use (40.3%) and a significantly higher prevalence of opioid use among respondents with cancer. In the midst of an opioid epidemic, an evolving political landscape, and new developments in oncology, quantifying the prevalence of opioid and marijuana use in the US population, especially among patients with cancer, is particularly relevant. Although opioid use did not significantly change from 2005 to 2014 among all respondents, marijuana use did increase, likely reflecting increased availability and legislative changes. A cancer diagnosis did not significantly affect longitudinal opioid or marijuana use.