title: Relative incidence of common cancers in people with severe mental illness. Cohort study in the United Kingdom THIN primary care database.
abstract: BACKGROUND
  A recent United Kingdom (UK) report found that breast and colorectal cancers were more common in people with severe mental illness (SMI) and recommended targeted screening. Epidemiological evidence is however inconsistent.
  
  
  OBJECTIVE
  To estimate relative incidence rates for colorectal, breast and lung cancer, and the overall incidence of the commonest other UK cancers, in people with SMI compared with people without SMI.
  
  
  METHODS
  Cohort study in the UK using The Health Improvement Network (THIN) primary care database between 1990 and June 2008. Poisson regression was used to obtain adjusted incidence rate ratios (IRRs) for cancer, comparing two cohorts of people over 18; with and without a diagnosis of SMI.
  
  
  RESULTS
  We identified 20,632 people with SMI and 116,152 people without, with median follow up of over 6years. No significant associations were observed between SMI and cancers of the breast (adjusted IRR 1.17; 95% confidence interval 0.95-1.45), colon (0.70; 0.46-1.05), rectum (1.05; 0.65-1.69) or lung (0.84; 0.65-1.10). The adjusted IRR for an aggregate cancer outcome in SMI was 0.95; 0.85-1.06. Results were similar for schizophrenia and bipolar disorder.
  
  
  CONCLUSIONS
  In a cohort analysis within a large UK primary care database, the incidence of colo-rectal, breast and lung cancer, and of all common cancers, did not differ significantly in people with SMI, including schizophrenia, compared with people without SMI. Our results do not support enhanced screening procedures for cancer in people with SMI.
authors.affiliation: UCL Mental Health Sciences Unit, UCL, Charles Bell House, Riding House Street, London W1W 7EJ, UK. d.osborn@ucl.ac.uk
authors.forename: David P J
authors.initials: DP
authors.lastname: Osborn
authors.forename: Heather
authors.initials: H
authors.lastname: Limburg
authors.forename: Kate
authors.initials: K
authors.lastname: Walters
authors.forename: Irene
authors.initials: I
authors.lastname: Petersen
authors.forename: Michael
authors.initials: M
authors.lastname: King
authors.forename: Jane
authors.initials: J
authors.lastname: Green
authors.forename: Jo
authors.initials: J
authors.lastname: Watson
authors.forename: Irwin
authors.initials: I
authors.lastname: Nazareth
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000453:epidemiology; D008297:Male; D001523:Mental Disorders / Q000150:complications / Q000453:epidemiology*; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000453:epidemiology*; D017063:Outcome Assessment, Health Care; D011320:Primary Health Care / Q000706:statistics & numerical data; D012044:Regression Analysis; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult