title: Screening for colorectal cancer and advanced colorectal neoplasia in kidney transplant recipients: cross sectional prevalence and diagnostic accuracy study of faecal immunochemical testing for haemoglobin and colonoscopy.
abstract: OBJECTIVE
  To investigate whether screening kidney transplant recipients aged over 50 years for colorectal cancer with a faecal immunochemical test for haemoglobin might be justified, by determining the prevalence of advanced colorectal neoplasia and evaluating the diagnostic accuracy of faecal haemoglobin testing compared with colonoscopy in a population of kidney transplant recipients at otherwise average risk.
  
  
  METHODS
  Cross sectional prevalence and diagnostic accuracy study with index test of faecal haemoglobin and reference standard of colonoscopy.
  
  
  METHODS
  Outpatient clinics in metropolitan and regional hospitals in South Australia.
  
  
  METHODS
  229 kidney transplant recipients aged 50 years and over, who were at least 6 months (mean 9.0 (SD 8.4) years) post-transplant and otherwise at average risk of colorectal cancer, completed the study between June 2008 and October 2011.
  
  
  METHODS
  Faecal immunochemical testing (Enterix Insure) for human haemoglobin, followed by colonoscopy with histological evaluation of retrieved samples.
  
  
  METHODS
  Prevalence of advanced colorectal neoplasia, defined as an adenoma at least 10 mm in diameter, villous features, high grade dysplasia, or colorectal cancer; sensitivity, specificity, and predictive values of faecal haemoglobin testing for advanced neoplasia compared with colonoscopy.
  
  
  RESULTS
  Advanced colorectal neoplasia was found in 29 (13%, 95% confidence interval 9% to 18%) participants, including 2% (n=4) with high grade dysplasia and 2% (n=5) with colorectal cancer. Faecal testing for haemoglobin was positive in 12% (n=28); sensitivity, specificity, and positive and negative predictive values for advanced neoplasia were 31.0% (15.3% to 50.8%), 90.5% (85.6% to 94.2%), 32.1% (15.9% to 52.4%), and 90.1% (85.1% to 93.8%). Colonoscopy was well tolerated, with no significant adverse outcomes. To identify one case of advanced neoplasia, 8 (6 to 12) colonoscopies were needed.
  
  
  CONCLUSIONS
  Kidney transplant recipients aged over 50 years have a high prevalence of advanced colorectal neoplasia. Faecal haemoglobin screening for colorectal neoplasia has similar performance characteristics in transplant recipients to those reported in general population studies, with poor sensitivity but reasonable specificity. Surveillance colonoscopy might be a more appropriate approach in this population.
  
  
  BACKGROUND
  Australian New Zealand Clinical Trials Registry ACTRN12608000154303.
authors: Central Northern Adelaide Renal and Transplantation Service, Royal Adelaide Hospital, Adelaide, SA 5000, Australia.
authors: Michael G
authors: MG
authors: Collins
authors: Edward
authors: E
authors: Teo
authors: Stephen R
authors: SR
authors: Cole
authors: Choy-Yoke
authors: CY
authors: Chan
authors: Stephen P
authors: SP
authors: McDonald
authors: Graeme R
authors: GR
authors: Russ
authors: Graeme P
authors: GP
authors: Young
authors: Peter A
authors: PA
authors: Bampton
authors: P Toby
authors: PT
authors: Coates
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D003430:Cross-Sectional Studies; D005243:Feces / Q000737:chemistry; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000453:epidemiology; D006454:Hemoglobins; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000601:surgery; D016030:Kidney Transplantation / Q000706:statistics & numerical data*; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging; D009780:Occult Blood; D015995:Prevalence; D012007:Rectum; D012680:Sensitivity and Specificity
chemical_list: D006454:Hemoglobins