Mental illness and non-metastatic colorectal cancer treatment and survival, a nationwide study of almost 70,000 patients.

BACKGROUND AND PURPOSE: The impact of mental illness on treatment and outcomes for patients with colorectal cancer (CRC) has not been investigated with potential confounders and mediators accounted for.

PATIENTS AND

METHODS

Colorectal Cancer Database (CRCBaSe), a linked national registry database, was used to analyse stage I-III CRC patients diagnosed in Sweden between 2008 and 2021. The exposure of interest was a history of mental illness. Treatment outcomes were analysed with logistic regressions. Flexible parametric models were fitted for survival analysis. Analyses were adjusted for pre-specified confounders.

RESULTS

Patients with a history of severe mental illness presented with more advanced tumours and comorbidities. They were more likely to undergo emergency surgery (OR 1.56, 95% CI 1.32-1.84) and less likely to receive adjuvant treatment (OR 0.65, 95% CI 0.53-0.80) than patients with no history of mental illness. Five-year standardised overall survival (OS) was worse for those with a history of mild and severe mental illness, 64.6% (95%CI 63.9-65.3) and 61.8% (95%CI 59.7-63.8) compared to those without 69.3% (95%CI 68.9-69.7). Although time to recurrence was not significantly impacted, standardised survival after recurrence was worse for patients with a history of severe mental illness, with a 3-year survival after recurrence of 24% compared to 30% in those without a history of mental illness.

INTERPRETATION: Although the differences were smaller compared to previous studies, patients with a history of mental illnesses still do worse. The management of CRC patients with psychiatric comorbidities presents complex challenges necessitating personalised solutions.