Integrating Cancer and Mental Health Care: Evidence and Pathways Toward Equity for People Living with Serious Mental Illness

Background: People living with serious mental illness (SMI) experience significantly poorer cancer outcomes and premature mortality compared to the general population. These inequities stem from systemic fragmentation between oncology, psychiatry, and primary care, compounded by stigma, diagnostic overshadowing, and socioeconomic disadvantage. While integrated care is a recognized principle across health systems, its translation into cancer pathways for people with SMI remains limited. This study synthesizes international evidence on integrated cancer–mental health interventions and identifies core components required to achieve equitable, person-centred cancer care.

 

Approach: A systematic review was conducted in accordance with PRISMA guidelines and preregistered on PROSPERO. Six databases (CINAHL, Medline, Web of Science, PsycINFO, Scopus, Embase) were searched from inception to 2025. Studies were eligible if they addressed adults with SMI receiving integrated cancer care interventions across prevention, diagnosis, treatment, survivorship, or palliative care.

Data extraction used the TIDieR framework, and methodological quality was assessed with the Mixed Methods Appraisal Tool (MMAT). A thematic synthesis identified shared integration mechanisms, outcomes, and implementation enablers and barriers.

 

Results: Nine studies (2016–2025) from Denmark, Japan, the UK, and the USA met inclusion criteria, including randomized trials, cohort analyses, qualitative studies, and complex intervention developments. Despite contextual diversity, a consistent logic of integration emerged—linking oncology, psychiatry, and primary care through coordinated multidisciplinary collaboration, care navigation, and workforce preparation. Evidence indicated that structured case management and navigation substantially improved access and engagement: colorectal cancer screening increased fourfold among individuals with schizophrenia (47.1% vs 11.8%), mammography completion reached 67%, and enhanced primary care models reduced inpatient stays by up to three days per patient annually.

 Qualitative insights revealed that relational continuity, trust-building, and caregiver inclusion were essential to sustaining engagement and adherence throughout the cancer pathway. Barriers to implementation included limited protected time for navigators, lack of funding for coordination activities, variable primary care participation, and uneven access to psychosocial and community supports. Facilitators included online multidisciplinary meetings, manualised protocols, and equity-driven training for oncology professionals to build confidence in caring for people with SMI.

 

Implications: The synthesis highlights actionable mechanisms through which integration can close cancer outcome gaps for people with SMI: early identification of psychiatric comorbidity, structured coordination between oncology and mental health teams, personalised navigation and decision support, continuity across care phases, and data-enabled learning systems. Integrating cancer and mental health care is feasible, effective, and essential to advancing health equity. Embedding these mechanisms into routine cancer pathways offers a pragmatic route to reduce preventable mortality among people with SMI and to realise the core principles of integrated, person-centred care across sectors.