J Psychosoc Oncol. 2026 Oct 12:1-20. doi: 10.1080/07347332.2026.2744357. Online ahead of print.
ABSTRACT
BACKGROUND: Adults living with cancer and pre-existing mental illness (PMI) represent a particularly vulnerable population. This study examined whether multimorbidity protects against or increases mortality among adults with cancer and PMI.
METHODS: We used Alberta Health Services administrative data (n = 15,144), to identify adults with both PMI and cancer diagnosed between 2013-2022, including demographic, comorbidity, and cancer information. The analysis used Cox proportional hazard models (HR) to evaluate the impact among different multimorbidity categories on all-cause mortality. The multimorbidity categories were classified as cardiometabolic (e.g. cardiovascular disease), musculoskeletal (e.g. rheumatic disease), chronic airway (e.g. chronic pulmonary disease), and general multimorbidity (e.g. including liver and renal disease). Multimorbidity combinations were defined as the presence of conditions across two or more categories.
RESULTS: In a cohort of 15,144 adults with cancer, 39.1% died during follow-up. In the overall cohort, compared with those without multimorbidity, adjusted models showed that multimorbidity increased mortality for cardiometabolic conditions (HR = 1.25, 95%CI 1.13-1.37), chronic airway disease (HR = 1.88, 95%CI 1.69-2.08), general multimorbidity (HR = 1.90, 95%CI 1.59-2.27), and multimorbidity combinations (HR = 2.29, 95%CI 2.08-2.51). Musculoskeletal conditions were not significant. By PMI subtype, multimorbidity combinations were consistently associated with increased mortality across mood, anxiety, substance use, and multiple psychiatric disorders (HRs = 1.67-1.91). General multimorbidity was associated with increased mortality in anxiety, substance use, and multiple psychiatric disorders (HRs = 1.72-2.74), whereas chronic airway disease was significant only in mood disorders. Cardiometabolic and musculoskeletal conditions were not associated with mortality after adjustment.
CONCLUSIONS: Different multimorbidity categories are associated with increased mortality among adults with cancer and PMI. These findings underscore the importance of jointly considering psychiatric and physical health comorbidities in cancer care.
PMID:42861824 | DOI:10.1080/07347332.2026.2744357