title: Development and external validation of a faecal immunochemical test-based prediction model for colorectal cancer detection in symptomatic patients.
abstract: Risk prediction models for colorectal cancer (CRC) detection in symptomatic patients based on available biomarkers may improve CRC diagnosis. Our aim was to develop, compare with the NICE referral criteria and externally validate a CRC prediction model, COLONPREDICT, based on clinical and laboratory variables.
  
  
  
  This prospective cross-sectional study included consecutive patients with gastrointestinal symptoms referred for colonoscopy between March 2012 and September 2013 in a derivation cohort and between March 2014 and March 2015 in a validation cohort. In the derivation cohort, we assessed symptoms and the NICE referral criteria, and determined levels of faecal haemoglobin and calprotectin, blood haemoglobin, and serum carcinoembryonic antigen before performing an anorectal examination and a colonoscopy. A multivariate logistic regression analysis was used to develop the model with diagnostic accuracy with CRC detection as the main outcome.
  
  
  
  We included 1572 patients in the derivation cohort and 1481 in the validation cohorts, with a 13.6 % and 9.1 % CRC prevalence respectively. The final prediction model included 11 variables: age (years) (odds ratio [OR] 1.04, 95 % confidence interval [CI] 1.02-1.06), male gender (OR 2.2, 95 % CI 1.5-3.4), faecal haemoglobin ≥20 μg/g (OR 17.0, 95 % CI 10.0-28.6), blood haemoglobin <10 g/dL (OR 4.8, 95 % CI 2.2-10.3), blood haemoglobin 10-12 g/dL (OR 1.8, 95 % CI 1.1-3.0), carcinoembryonic antigen ≥3 ng/mL (OR 4.5, 95 % CI 3.0-6.8), acetylsalicylic acid treatment (OR 0.4, 95 % CI 0.2-0.7), previous colonoscopy (OR 0.1, 95 % CI 0.06-0.2), rectal mass (OR 14.8, 95 % CI 5.3-41.0), benign anorectal lesion (OR 0.3, 95 % CI 0.2-0.4), rectal bleeding (OR 2.2, 95 % CI 1.4-3.4) and change in bowel habit (OR 1.7, 95 % CI 1.1-2.5). The area under the curve (AUC) was 0.92 (95 % CI 0.91-0.94), higher than the NICE referral criteria (AUC 0.59, 95 % CI 0.55-0.63; p < 0.001). On the basis of the thresholds with 90 % (5.6) and 99 % (3.5) sensitivity, we divided the derivation cohort into three risk groups for CRC detection: high (30.9 % of the cohort, positive predictive value [PPV] 40.7 %, 95 % CI 36.7-45.9 %), intermediate (29.5 %, PPV 4.4 %, 95 % CI 2.8-6.8 %) and low (39.5 %, PPV 0.2 %, 95 % CI 0.0-1.1 %). The discriminatory ability was equivalent in the validation cohort (AUC 0.92, 95 % CI 0.90-0.94; p = 0.7).
  
  
  
  COLONPREDICT is a highly accurate prediction model for CRC detection.
authors: Gastroenterology Department, Complexo Hospitalario Universitario de Ourense, Rua Ramón Puga 52-54, 32005, Ourense, Spain. joaquin.cubiella.fernandez@sergas.es.|Instituto de Investigación Biomedica (IBI) Ourense, Pontevedra y Vigo, Vigo, Rua Ramón Puga 52-54, 32003, Ourense, Spain. joaquin.cubiella.fernandez@sergas.es.
authors: Joaquín
authors: J
authors: Cubiella
authors: Gastroenterology Department, Complexo Hospitalario Universitario de Ourense, Rua Ramón Puga 52-54, 32005, Ourense, Spain.
authors: Pablo
authors: P
authors: Vega
authors: Gastroenterology Department, Complexo Hospitalario Universitario de Ourense, Rua Ramón Puga 52-54, 32005, Ourense, Spain.
authors: María
authors: M
authors: Salve
authors: Clinical Analysis Department, Complexo Hospitalario Universitario de Ourense, Rua Ramón Puga 52-54, 32003, Ourense, Spain.
authors: Marta
authors: M
authors: Díaz-Ondina
authors: NECOM Group, University of Vigo, Campus Universitario As Lagoas, Marcosende, 36310, Vigo, Spain.
authors: Maria Teresa
authors: MT
authors: Alves
authors: Gastroenterology Department, Hospital Universitario de Canarias, Instituto Universitario de Tecnologías Biomédicas (ITB) & Centro de Investigación Biomédica de Canarias (CIBICAN), Universidad de La Laguna, Carretera de Ofra, s/n, 38320, San Cristóbal de La Laguna, Santa Cruz de Tenerife, Spain.
authors: Enrique
authors: E
authors: Quintero
authors: Gastroenterology Department, Complejo Hospitalario de Pontevedra, Av. Montecelo, 36164 Casas Novas, Pontevedra, Spain.
authors: Victoria
authors: V
authors: Álvarez-Sánchez
authors: Gastroenterology Department, Hospital Universitari Mútua de Terrassa, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Plaça del Doctor Robert, 5, 08221, Terrassa, Barcelona, Spain.
authors: Fernando
authors: F
authors: Fernández-Bañares
authors: Gastroenterology Department, Consorci Sanitari de Terrassa, Carr. Torrebonica, S/N, 08227, Terrassa, Barcelona, Spain.
authors: Jaume
authors: J
authors: Boadas
authors: Gastroenterology Department, Hospital de Sabadell, Corporació Sanitària i Universitària Parc Taulí, Parc Taulí, 1, 08208, Sabadell, Barcelona, Spain.
authors: Rafel
authors: R
authors: Campo
authors: Donostia Hospital, Biodonostia Institute, University of the Basque Country UPV/EHU, (CIBERehd), Paseo del Doctor Begiristain 117, 20080, San Sebastian, Guipuzcoa, Spain.
authors: Luis
authors: L
authors: Bujanda
authors: Gastroenterology Department, Hospital de Sagunto, Avenida Ramón y Cajal, S/N, 46520, Sagunto, Valencia, Spain.
authors: Joan
authors: J
authors: Clofent
authors: Servicio de Aparato Digestivo, Hospital Clínico Universitario, IIS Aragón, University of Zaragoza, (CIBERehd), Avda. San Juan Bosco, 15, 50009, Zaragoza, Spain.
authors: Ángel
authors: Á
authors: Ferrandez
authors: Gastroenterology Department, Hospital Dr. Josep Trueta, Avenida de Francia, s/n, 17007, Girona, Spain.
authors: Leyanira
authors: L
authors: Torrealba
authors: Gastroenterology Department, Hospital Dr. Josep Trueta, Avenida de Francia, s/n, 17007, Girona, Spain.
authors: Virginia
authors: V
authors: Piñol
authors: Digestive Disease Section, Hospital Universitario de Móstoles Río Júcar, s/n, 28935, Mostoles, Madrid, Spain.
authors: Daniel
authors: D
authors: Rodríguez-Alcalde
authors: Instituto de Investigación Biomedica (IBI) Ourense, Pontevedra y Vigo, Vigo, Rua Ramón Puga 52-54, 32003, Ourense, Spain.|Gastroenterology Department, Vigo, Pontevedra, Spain.
authors: Vicent
authors: V
authors: Hernández
authors: Gastroenterology Department, Complexo Hospitalario Universitario de Ourense, Rua Ramón Puga 52-54, 32005, Ourense, Spain.|Instituto de Investigación Biomedica (IBI) Ourense, Pontevedra y Vigo, Vigo, Rua Ramón Puga 52-54, 32003, Ourense, Spain.
authors: Javier
authors: J
authors: Fernández-Seara
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis; D002272:Carcinoembryonic Antigen / Q000032:analysis*; D003113:Colonoscopy / Q000379:methods; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000473:pathology; D003430:Cross-Sectional Studies; D055088:Early Detection of Cancer / Q000379:methods; D005243:Feces; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007120:Immunochemistry / Q000379:methods; D039841:Leukocyte L1 Antigen Complex / Q000032:analysis*; D008297:Male; D008962:Models, Theoretical; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods
chemical_list: D015415:Biomarkers; D002272:Carcinoembryonic Antigen; D006454:Hemoglobins; D039841:Leukocyte L1 Antigen Complex
keywords: Colonoscopy; Colorectal cancer; Diagnostic accuracy; Faecal immunochemical test; Prompt diagnosis; Risk stratification