A systematic review of substance use and substance use disorders in patients with cancer

Objective: Few studies examined substance use in cancer patients. The aims of this systematic review were to summarize this evidence, identify methodological limitations, and provide future research directions. Method: Articles on substance use in cancer (focused on illicit substance, opioid, and alcohol use) were searched in Medline, PsycINFO, and PsycARTICLES. Results: On the basis of inclusion criteria, 28 studies were reviewed. Twenty-one contained empiric data from 500,123 participants; seven were review or conceptual papers. All studies were published between 1995 and 2018. Quality assessment revealed relatively low risk of bias and high methodological quality. Five studies examined substance use or substance use disorder (SUD) broadly. Mean ages ranged from 17.6 to 74.7 years. Substance use rates ranged from 2% to 35%, with a median opioid rate of 18% and 25.5% for alcohol. Nine of the studies had samples comprised either mostly or exclusively of advanced cancer patients. Disease groups included breast, head & neck, and gastric cancer. None of the studies used a theoretical framework or model. Conclusions: Given the prevalence of substance use in cancer patients, interventions are needed. Further theory-grounded studies are warranted to foster the translation of research into clinical practice and elucidate substance use management recommendations.