Stage at diagnosis and survival in patients with cancer and a pre-existing mental illness: a meta-analysis

• Published in: Journal of epidemiology and community health (1979) 2020-01, Vol.74 (1), p.84-94
• Main Authors: Davis, Laura E, Bogner, Emma, Coburn, Natalie G, Hanna, Timothy P, Kurdyak, Paul, Groome, Patti A, Mahar, Alyson L
• Format: Article
• Language: English
• Subjects: Cancer; Cancer Survivors - psychology; Cognitive ability; Diagnosis; Fatalities; Heterogeneity; Humans; Medical diagnosis; Mental disorders; Mental Disorders - complications; Mental Disorders - diagnosis; Meta-analysis; Metastases; Mortality; Neoplasm Staging; Neoplasms - diagnosis; Neoplasms - mortality; Neoplasms - pathology; Observational studies; Observational Studies as Topic; Quality control; Risk assessment; Schizophrenia; Severity of Illness Index; Studies; Survival; Systematic review
• ISSN: 0143-005X; 1470-2738
• DOI: 10.1136/jech-2019-212311

IntroductionIndividuals with a pre-existing mental illness, especially those experiencing reduced social, occupational and functional capacity, are at risk for cancer care disparities. However, uncertainty surrounding the effect of a mental illness on cancer outcomes exists.MethodsWe conducted a systematic review and meta-analysis of observational studies using MEDLINE and PubMed from 1 January 2005 to 1 November 2018. Two reviewers evaluated citations for inclusion. Advanced stage was defined as regional, metastatic or according to a classification system. Cancer survival was defined as time survived from cancer diagnosis. Pooled ORs and HRs were presented. The Newcastle-Ottawa bias risk assessment scale was used. Random-effects models used the Mantel-Haenszel approach and the generic inverse variance method. Heterogeneity assessment was performed using I2.Results2381 citations were identified; 28 studies were included and 24 contributed to the meta-analysis. Many demonstrated methodological flaws, limiting interpretation and contributing to significant heterogeneity. Data source selection, definitions of a mental illness, outcomes and their measurement, and overadjustment for causal pathway variables influenced effect sizes. Pooled analyses suggested individuals with a pre-existing mental disorder have a higher odds of advanced stage cancer at diagnosis and are at risk of worse cancer survival. Individuals with more severe mental illness, such as schizophrenia, are at a greater risk for cancer disparities.DiscussionThis review identified critical gaps in research investigating cancer stage at diagnosis and survival for individuals with pre-existing mental illness. High-quality research is necessary to support quality improvement for the care of psychiatric patients and their families during and following a cancer diagnosis.