Risk of Prostate Cancer in Patients with Schizophrenia.

OBJECTIVES:To examine the rate of prostate cancer in a cohort of schizophrenia in-patients in the PSA-era as compared to expected rates. There is conflicting evidence on the relative risk of prostate cancer in men with schizophrenia.METHODS:the study sample was comprised of schizophrenia patients who had been admitted to a tertiary care mental health center between 1990 and 2011. The data for the sample was cross-referenced with the National Cancer Registry. Analyses of Standardized Incidence Rates (SIR) for prostate cancer and for lung cancer (representing an organ system not sensitive to sex hormones) were performed.RESULTS:Of 4,326 schizophrenia patients included in the present study, 181 (4.2%) were diagnosed with cancer at any site. Only 10 of these patients were diagnosed with prostate cancer. This reflects a reduced risk; SIR of 0.56 (95% CI 0.27-1.03). In the same cohort, 33 schizophrenia patients were diagnosed with lung cancer presenting a SIR of 1.43 (95% CI 0.98-2.01) in this sample.CONCLUSIONS:The present study suggests a reduced rate of prostate cancer in patients admitted for schizophrenia. There are several possible explanations for this finding including chronic state of hyperprolactinemia induced by antipsychotic drugs.