The Impact of Preexisting Severe Mental Disorders on Cancer Mortality: A Systematic Review and Meta-Analysis

PURPOSE: People with severe mental disorders (SMD) face a significantly lower life expectancy compared to people without SMD. Studies have reported divergent results concerning cancer-specific mortality. Therefore this systematic review and meta-analysis aimed to assess the cancer-specific mortality for people with preexisting SMD.

METHODS: A comprehensive literature search was conducted across PubMed, Embase, Psycinfo, and Scopus for studies published since January 2003. Inclusion criteria targeted adult cancer patients with a known SMD diagnosis prior to their cancer diagnosis. Two authors independently screened records based on predefined criteria, resolving discrepancies through discussion. Data extraction and quality assessment were conducted using the Newcastle-Ottawa Scale. A random effects model was employed to conduct the analysis, with heterogeneity across the studies quantified using the I2 statistic.

RESULTS: The search yielded 4736 records, of which 25 studies met the eligibility criteria. Findings consistently indicated higher cancer-specific mortality among patients with preexisting SMD, with a 1.37 (95% CI: 1.30-1.44) higher relative risk of cancer-specific mortality for patients with preexisting SMD. The highest mortality rates were found among patients with schizophrenia and other psychosis with a relative cancer mortality risk at 1.47 (95% CI: 1.33-1.63).

CONCLUSION: This review and meta-analysis highlighted a concerning higher relative cancer-specific mortality risk for patients with preexisting SMD. These findings underscore the need for integrated healthcare approaches addressing both cancer treatment and mental health to improve outcomes for this vulnerable population.