Substance use disorder and its effects on outcomes in men with advanced-stage prostate cancer.

BACKGROUND: Substance use disorder in patients with cancer has implications for outcomes. The objective of this study was to analyze the effects of the type and timing of substance use on outcomes in elderly Medicare recipients with advanced prostate cancer. METHODS: This was an observational cohort study using Surveillance, Epidemiology, and End Results (SEER)-Medicare linked data from 2000 to 2009. Among men who were diagnosed with advanced prostate cancer between 2001 and 2004, we identified those who had a claim for substance use disorder in the year before cancer diagnosis, 1 year after cancer diagnosis, and an additional 4 years after diagnosis. The outcomes investigated were use of health services, costs, and mortality. RESULTS: The prevalence of substance use disorder was 10.6%. The category drug psychoses and related had greater odds of inpatient hospitalizations (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.9-2.8), outpatient hospital visits (OR, 2.6; 95% CI, 1.9-3.6), and emergency room visits (OR, 1.7; 95% CI, 1.2-2.4). Substance use disorder in the follow-up phase was associated with greater odds of inpatient hospitalizations (OR, 2.0; 95% CI, 1.8-2.2), outpatient hospital visits (OR, 2.0; 95% CI, 1.7-2.4), and emergency room visits (OR, 1.7; 95% CI, 1.5-2.1). Compared with men who did not have substance use disorder, those in the category drug psychoses and related had 70% higher costs, and those who had substance use disorder during the follow-up phase had 60% higher costs. The hazard of all-cause mortality was highest for patients in the drug psychoses and related category (hazard ratio, 1.3; 95% CI, 1.1-1.7) and the substance use disorder in treatment phase category (hazard ratio, 1.5; 95% CI, 1.3-1.7). CONCLUSIONS: The intersection of advanced prostate cancer and substance use disorder may adversely affect outcomes. Incorporating substance use screening and treatments into prostate cancer care guidelines and coordination of care is desirable.