Emergency colon cancer diagnosis in people with mental health conditions: a population-based cohort study in northern Italy

Background: Individuals with mental health conditions may experience disparity in cancer diagnosis and health outcomes. This study aims to examine diagnostic pathways and mortality in patients with colon cancer with pre-existing mental health conditions. // Methods: A population-based cohort study on colon cancer cases diagnosed in 2014–2020 in the provinces of Milan and Lodi, using linked cancer registration and health data. We examined cancer diagnostic pathways (screening, emergency presentation (EP), inpatient/outpatient visits) and short-term mortality in patients with and without pre-existing mental health conditions, accounting for physical comorbidities and sociodemographic factors. Mental health conditions were systematically categorised into distinct groups according to the International Classification of Diseases, 10th Revision. // Results: Out of 11 429 patients with colon cancer, 16.2% had a pre-existing mental health condition. Individuals with mental health conditions versus those without had a higher risk of cancer diagnosis following EP: 43.8% versus 33.8%, adjusted OR (aOR) 1.32, 95% CI 1.19 to 1.47. EP risk was higher for patients with diagnoses of dementia and related cognitive conditions (aOR 1.69, 95% CI 1.41 to 2.03), substance use/behavioural syndromes/personality-related conditions (aOR 1.92, 95% CI 1.34 to 2.75) and anxiety (aOR 1.44, 95% CI 1.16 to 1.79). The likelihood of screening-detected cancer was lower (4.6% vs 9.1%; aOR 0.78, 95% CI 0.60 to 0.99), especially for dementia and related cognitive conditions (aOR 0.27, 95% CI 0.08 to 0.86). Short-term mortality was higher in patients with cancer with mental health conditions than in those without. // Conclusion: Mental health conditions were associated with a lower likelihood of screening and a higher risk of emergency cancer diagnosis. Tailored strategies are warranted to enhance cancer diagnosis for the non-negligible group of individuals with mental health conditions.