Colorectal cancer mortality in persons with severe mental illness: a scoping review with meta-analyses of observational studies.

Abstract

Background and purpose: Persons with severe mental illnesses (SMIs) have reduced participation in colorectal cancer (CRC) screening programs, higher odds of advanced stage at diagnosis, and are less likely to receive adequate treatment than the general population. It remains unclear to what extent these factors impact CRC outcomes for persons with SMI. The aim of this scoping review was to describe and quantify CRC mortality for persons with SMI compared with the general population.

Patients/materials and methods: We followed the JBI Manual for Evidence Synthesis and PRISMA guidelines in a systematic search of four databases from inception until April 29th, 2024. We included studies that provided CRC mortality estimates for adults with preexisting clinical diagnosis of SMI. We synthesized the results descriptively and pooled the data to estimate the magnitude of the associations.

Results: Twenty-four original studies were identified with a total of 16.4 million persons. Most studies reported increased CRC mortality for persons with SMI compared with persons without SMI. The meta-analysis demonstrated a 25% increased CRC mortality for persons with SMI (e.g. pooled hazard ratio 1.25; 95% confidence interval 1.13 to 1.39; n = 13,178,161).

Interpretation: The evidence points consistently to an increased CRC mortality for persons with SMI compared with persons without SMI. Furthermore, this evidence supports the idea that persons with SMI are a heterogenous population, and as such, any future initiatives to improve CRC outcomes for persons with SMI would warrant a tailored approach to potentiate individual resources, to mitigate stigma and structural discrimination.