Cancer incidence in patients with schizophrenia and their first-degree relatives – a meta-analysis
Article first published online: 10 MAR 2008
© 2008 The Authors
Acta Psychiatrica Scandinavica
Volume 117, Issue 5, pages 323–336, May 2008
How to Cite
Catts, V. S., Catts, S. V., O’Toole, B. I. and Frost, A. D. J. (2008), Cancer incidence in patients with schizophrenia and their first-degree relatives – a meta-analysis. Acta Psychiatrica Scandinavica, 117: 323–336. doi: 10.1111/j.1600-0447.2008.01163.x
- Issue published online: 10 MAR 2008
- Article first published online: 10 MAR 2008
- Accepted for publication January 4, 2008
Objective: Controversy concerning cancer incidence in schizophrenia exists because of heterogeneous study findings.
Method: A meta-analysis was performed on standardized incidence ratios (SIR) of cancer in patients with schizophrenia and first-degree relatives and compared with general population samples.
Results: The pooled overall cancer incidence in patients was not significantly increased (SIR = 1.05, CI 0.95–1.15). Lung cancer incidence was slightly increased (SIR = 1.31, CI 1.01–1.71), but was reduced after adjusting for smoking prevalence. The incidence of several cancers unrelated to smoking was reduced in patients. Breast cancer rates were significantly increased in female patients. The pooled overall cancer incidence in siblings (SIR = 0.89, CI 0.84–0.94) and parents (SIR = 0.90, CI 0.88–0.93) was significantly reduced. A meta-regression detected a significant relationship between cancer risk in the general population and relative risk in patients.
Conclusion: The meta-analysis aided exploration of inconsistent study findings. There is a discrepancy between cancer risk exposure and cancer incidence in schizophrenia consistent with a protective effect.