Impact of serious mental illness on the treatment and mortality of older patients with locoregional high-grade (nonmetastatic) prostate cancer: retrospective cohort analysis of 49 985 SEER-Medicare patients diagnosed between 2006 and 2013

Background: The influence of serious mental illness (SMI) on the treatment and survival of patients with high-grade prostate cancer is not well understood. We compared the initial cancer treatment and cancer-specific mortality of SEER-Medicare patients with locoregional high-grade (nonmetastatic) prostate cancer with and without preexisting SMI. Methods: We identified SEER-Medicare patients who were 67 years of age or older diagnosed between 2006 and 2013 with locoregional high-grade (nonmetastatic) prostate cancer. Preexisting SMI was identified by claims indicative of bipolar disorder, schizophrenia, and other psychotic disorder, during the 2 years before cancer diagnosis. We used multivariable binary logistic regression to examine associations between SMI and receipt of surgery or radiation concurrent with hormone therapy (definitive initial treatment) within 1 year after cancer diagnosis. We used Kaplan-Meier survival curves, as well as Cox proportional hazards and competing risk models to evaluate unadjusted and adjusted associations between SMI and 5-year cancer-specific survival. Results: Among 49 985 patients with locoregional high-grade (nonmetastatic) prostate cancer, 523 (1.1%) had SMI and 49 462 (98.9%) had no SMI. Overall, SMI was associated with reduced odds of receiving surgery (OR = 0.66, 95% CI: 0.49-0.89) or radiation concurrent with hormone therapy (OR = 0.81, 95% CI: 0.67-0.98) as initial treatments in the year after cancer diagnosis. Additionally, SMI was associated with higher hazard of 5-year cancer-specific death (HR = 1.41, 95% CI: 1.06-1.89) after accounting for competing risks of non-cancer death. Conclusion: Among SEER-Medicare patients with locoregional high-grade (nonmetastatic) prostate cancer, those with preexisting SMI—relative to those without these conditions—were less likely to receive definitive initial treatment in the year after diagnosis and had poorer cancer-specific survival 5 years after diagnosis.