title: Diagnostic performance of fecal immunochemical test and sigmoidoscopy for advanced right-sided colorectal neoplasms.
abstract: BACKGROUND
  Colorectal cancer screening effect on right-sided colorectal neoplasia is limited. We compared fecal immunochemical test and simulated sigmoidoscopy diagnostic accuracy for advanced right-sided neoplasia detection.
  
  
  METHODS
  We analyzed 1,292 individuals with complete screening colonoscopy with a fecal immunochemical test determination before colonoscopy. Sigmoidoscopy and "hybrid strategy" (sigmoidoscopy or fecal hemoglobin concentration ≥ 20 µg hemoglobin/g) diagnostic yield were simulated according to UK Flexible Sigmoidoscopy, Screening for COlon REctum (SCORE), and Norwegian Colorectal Cancer Prevention (NORCCAP) trials criteria to complete colonic examination. We compared sensitivity and specificity of both strategies and of "hybrid strategy" for advanced right-sided neoplasia with McNemar test.
  
  
  RESULTS
  An advanced right-sided neoplasia was detected in 47 (3.6 %) subjects. A fecal hemoglobin concentration ≥ 20 µg hemoglobin/g was determined in 6.6 % of the subjects and 10.1, 12.7, and 23.5 % met UK, SCORE, and NORCCAP criteria, respectively. Fecal immunochemical test was statistically more specific than sigmoidoscopy strategies (93.8 %, UK 90.3 %, SCORE 87.7 %, NORCCAP 77.8 %; p < 0.001). In contrast, fecal immunochemical test sensitivity for advanced right-sided neoplasia (17 %) was not statistically different than UK (21.3 %; p = 0.7) or SCORE (23.4 %; p = 0.5), although it was inferior than NORCCAP strategy (42.5 %; p < 0.001). Adding fecal immunochemical test to sigmoidoscopy increased number of positives (8.5-25.7 %), sensitivity (10-30 %), and significantly reduced advanced right-sided neoplasia specificity (p < 0.001).
  
  
  CONCLUSIONS
  Fecal immunochemical test and sigmoidoscopy diagnostic yield for advanced right-sided neoplasia are low. Fecal immunochemical test is more specific than sigmoidoscopy but less sensitive than sigmoidoscopy according to NORCCAP criteria.
authors.affiliation: Department of Gastroenterology, Complexo Hospitalario Universitario de Ourense, Rua Ramón Puga 52-54, 32003, Ourense, Spain.
authors.forename: Inés
authors.initials: I
authors.lastname: Castro
authors.forename: Pamela
authors.initials: P
authors.lastname: Estevez
authors.forename: Joaquín
authors.initials: J
authors.lastname: Cubiella
authors.forename: Vicent
authors.initials: V
authors.lastname: Hernandez
authors.forename: Carmen
authors.initials: C
authors.lastname: González-Mao
authors.forename: Concepción
authors.initials: C
authors.lastname: Rivera
authors.forename: Felipe
authors.initials: F
authors.lastname: Iglesias
authors.forename: Lucía
authors.initials: L
authors.lastname: Cid
authors.forename: Santiago
authors.initials: S
authors.lastname: Soto
authors.forename: Luisa
authors.initials: L
authors.lastname: de-Castro
authors.forename: Pablo
authors.initials: P
authors.lastname: Vega
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Hermo
authors.forename: Ramiro
authors.initials: R
authors.lastname: Macenlle
authors.forename: Alfonso
authors.initials: A
authors.lastname: Martínez
authors.forename: Estela
authors.initials: E
authors.lastname: Cid
authors.forename: Inés
authors.initials: I
authors.lastname: Gil
authors.forename: Mikel
authors.initials: M
authors.lastname: Larzabal
authors.forename: Luis
authors.initials: L
authors.lastname: Bujanda
authors.forename: Antoni
authors.initials: A
authors.lastname: Castells
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009780:Occult Blood; D011237:Predictive Value of Tests; D011379:Prognosis; D012017:Referral and Consultation; D012812:Sigmoidoscopy; D013030:Spain