title: False-negative rate cannot be reduced by lowering the haemoglobin concentration cut-off in colorectal cancer screening using faecal immunochemical test.
abstract: The aim of this study was to analyse false-negative (FN) results of the faecal immunochemical test (FIT) and its determinants in a colorectal cancer screening programme in Catalonia. We carried out a cross-sectional study among 218 screenees with a negative FIT result who agreed to undergo a colonoscopy. A false-negative result was defined as the detection, at colonoscopy, of intermediate/high-risk polyps or colorectal cancer in a patient with a previous negative FIT (<20 µgHb/g). Multivariate logistic regression models were constructed to identify sociodemographic (sex, age) and screening variables (quantitative faecal haemoglobin, colonoscopy findings) related to FN results. Adjusted odds ratios and their 95% confidence intervals were estimated. There were 15.6% FN FIT results. Faecal haemoglobin was undetected in 45.5% of these results and was below 4 µgHb/g in 94.0% of the individuals with a FN result. About 60% of the lesions were located in the proximal colon, whereas the expected percentage was 30%. Decreasing the positivity threshold of FIT does not increase the detection rate of advanced neoplasia, but may increase the costs and potential adverse effects.
authors.affiliation: aCancer Prevention and Control Programme, Catalan Institute of Oncology, IDIBELL bDepartment of Gastroenterology and Hepatology, University Hospital of Bellvitge-IDIBELL cConsortium for Biomedical Research in Epidemiology and Public Health (CIBEResp) dDepartment of Gastroenterology and Hepatology, Hospital of Viladecans eDepartment of Clinical Sciences, University of Barcelona, Barcelona, Spain.
authors.forename: Gemma
authors.initials: G
authors.lastname: Ibañez-Sanz
authors.forename: Montse
authors.initials: M
authors.lastname: Garcia
authors.forename: Núria
authors.initials: N
authors.lastname: Milà
authors.forename: Francisco
authors.initials: F
authors.lastname: Rodríguez-Moranta
authors.forename: Gemma
authors.initials: G
authors.lastname: Binefa
authors.forename: Javier
authors.initials: J
authors.lastname: Gómez-Matas
authors.forename: Llúcia
authors.initials: L
authors.lastname: Benito
authors.forename: Isabel
authors.initials: I
authors.lastname: Padrol
authors.forename: Mercè
authors.initials: M
authors.lastname: Barenys
authors.forename: Victor
authors.initials: V
authors.lastname: Moreno
mesh_terms: D000368:Aged; D003106:Colon / Q000000981:diagnostic imaging; D003111:Colonic Polyps / Q000000981:diagnostic imaging*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D055088:Early Detection of Cancer / Q000009:adverse effects* / Q000191:economics / Q000379:methods; D005188:False Negative Reactions; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007120:Immunochemistry; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000009:adverse effects* / Q000191:economics / Q000379:methods; D008875:Middle Aged; D009780:Occult Blood; D016017:Odds Ratio
chemical_list: D006454:Hemoglobins