A possible link between the use of antipsychotics in schizophrenia and the risk of prostate cancer, "Beyond the Abstract," by Yoram Barak, MD, MHA

BERKELEY, CA (UroToday.com) - The advent of second generation antipsychotics has changed the practice of psychiatry in the last two decades. Antipsychotic use in the U.S. increased from 6.2 million (M) treatment visits in 1995 to 16.7M visits in 2006. This increase is in part due to the expansion in indications beyond the schizophrenia spectrum. Overall, antipsychotic use for indications without FDA approval increased from 4.4M visits in 1995 to 9.0M in 2008. The estimated cost associated with off-label use in 2008 was US$6.0 billion. Several regulatory agencies and researchers caution that the benefits of widening atypical antipsychotic use should be weighed against their cost and incomplete nature of available evidence as to efficacy and safety. One of the less researched risks associated with long-term antipsychotic exposure is the development of malignancy. The enormity of use of antipsychotic agents is nowadays acknowledged and thus, any possible adverse effects or involvement in changes in the risk of cancer affects a large and exposed cohort in our population.

Recent work established that schizophrenia is associated with a higher rate of premature mortality than observed in the general population; excess mortality is 2 to 3 times higher and the life expectancy is 20% shorter. Moreover, the mortality gap between the general population and patients with schizophrenia has widened in recent decades. Suicide, which is the main cause of this excess mortality, is nevertheless not sufficient to explain this excess. Schizophrenic patients suffer higher rates of somatic illnesses. In one of the largest prospective studies to date (N=3,470) a cohort of patients with schizophrenia was followed for 11 years. The mortality rate was nearly 4-fold higher than in the general population. Cancer was the second most frequent cause of mortality, with a global standardized mortality ratio of 1.9.

Antipsychotics-induced hyperprolactinemia, a presumed risk factor for prostate cancer, obesity, smoking, and alcohol abuse in this group confer additional risk. Coupled with limited access and use of medical care, characteristic of patients suffering from schizophrenia, make research into the association between hyperprolactinemia and prostate cancer a medical and public health priority.

The present study adds to the slowly growing body of research demonstrating that there need be a clear differentiation between cancer types and the "generalization" that exposure to antipsychotics "does" or "does not" increase cancer risk. Larger studies looking at heterogeneous patient populations exposed to antipsychotic-induced hyperprolactinemia are necessary to conclude that risk of prostate cancer is ruled-out.

Written by:
Yoram Barak, MD, MHA as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.

Abarbanel Mental Health Center, Bat-Yam, Israel; Sackler School of Medicine, Tel-Aviv University, Israel

Risk of prostate cancer in patients with schizophrenia - Abstract

More Information about Beyond the Abstract