title: Cancer survival in the context of mental illness: a national cohort study.
abstract: OBJECTIVE
  To explore the reasons for worse cancer survival in people with experience of mental illness, including differences by cancer type and psychiatric diagnosis.
  
  
  METHODS
  New Zealand breast and colorectal cancer registrations (2006-2010) were linked to psychiatric hospitalization records for adults (18-64 years). Cancer-specific survival was compared for recent psychiatric service users and nonusers using Cox regression. The contributions of deprivation, comorbidity and stage at diagnosis were assessed for those with schizophrenia or bipolar affective disorder (Group A) and others using mental health services (Group B).
  
  
  RESULTS
  Of 8762 and 4022 people with breast and colorectal cancer respectively, 440 (breast) and 190 (colorectal) had recent contact with psychiatric services. After adjusting for confounding, risk of death from breast cancer was increased for Group A [Hazard Ratio (HR) 2.55 (95% confidence interval 1.49-4.35)] and B [HR 1.62 (1.09-2.39)] and from colorectal cancer for Group A [HR 2.92 (1.75-4.87)]. Later stage at diagnosis contributed to survival differences for Group A, and comorbidity contributed for both groups. Fully adjusted HR estimates were breast: Group A 1.65 (0.96-2.84), B 1.41 (0.95-2.09); colorectal: Group A 1.89 (1.12-3.17), B 1.25 (0.89-1.75)].
  
  
  CONCLUSIONS
  The high burden of physical disease and delayed cancer diagnosis in those with psychotic disorders contributes to worse cancer survival in New Zealand psychiatric service users.
authors.affiliation: Department of Public Health, University of Otago Wellington. Electronic address: ruth.cunningham@otago.ac.nz.
authors.forename: Ruth
authors.initials: R
authors.lastname: Cunningham
authors.affiliation: Department of Public Health, University of Otago Wellington.
authors.forename: Diana
authors.initials: D
authors.lastname: Sarfati
authors.affiliation: Department of Public Health, University of Otago Wellington.
authors.forename: James
authors.initials: J
authors.lastname: Stanley
authors.affiliation: Social Psychiatry and Population Mental Health Research Group, University of Otago Wellington.
authors.forename: Debbie
authors.initials: D
authors.lastname: Peterson
authors.affiliation: Social Psychiatry and Population Mental Health Research Group, University of Otago Wellington.
authors.forename: Sunny
authors.initials: S
authors.lastname: Collings
mesh_terms: D000293:Adolescent; D000328:Adult; D001943:Breast Neoplasms / Q000401:mortality / Q000523:psychology*; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000401:mortality / Q000523:psychology*; D018572:Disease-Free Survival; D005260:Female; D006760:Hospitalization; D006778:Hospitals, Psychiatric; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000150:complications*; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D016016:Proportional Hazards Models; D055815:Young Adult
keywords: Breast neoplasms; Colorectal neoplasms; Healthcare disparities; Mental disorders; Schizophrenia