Identification of colorectal adenomas by a quantitative immunochemical faecal occult blood screening test depends on adenoma characteristics, development threshold used and number of tests performed.
Aliment Pharmacol Ther
; 29(8): 906-17, 2009 Apr 15.
Article
en En
| MEDLINE
| ID: mdl-19183147
BACKGROUND: Faecal occult blood tests (FOBT) are faulted by low sensitivity for advanced adenomatous polyps (AAP). Quantified, immunochemical, haemoglobin (Hb)-specific immunochemical FOBT (I-FOBT) measurements are now used for colorectal screening. AIMS: To correlate adenoma characteristics to amount of faecal Hb lost and to evaluate sensitivity and specificity for AAP by faecal Hb development threshold used and number of I-FOBTs collected. METHODS: Three daily I-FOBTs were collected and analysed in 1221 patients scheduled for colonoscopy. Faecal Hb was analysed as ngHb/mL of buffer and the highest result related to colonoscopy findings. RESULTS: In 1204 patients without cancer, colonoscopy identified adenomas in 294, 99 with AAPs. Adenoma patients had elevated faecal Hb increasing with advanced histology, size, pedunculated shape and multiplicity (P < 0.001 for all). At 50 ngHb/mL threshold, sensitivity and specificity for AAPs were 54.5% (95%CI 44.7, 64.7) and 88.1% (95%CI 86.2, 90.1) for three tests. At higher thresholds, sensitivity decreased, but was significantly higher with more samples collected. Conversely, specificity increased at higher thresholds, but decreased with more samples. CONCLUSIONS: Faecal Hb loss from adenomas is significantly associated with size, number and advanced features. Sensitivity and specificity for AAPs are determined by test threshold chosen and number of samples collected; these determine the number of colonoscopies needed for positive tests.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Hemoglobinas
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Inmunohistoquímica
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Neoplasias Colorrectales
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Adenoma
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Pólipos del Colon
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Sangre Oculta
Tipo de estudio:
Diagnostic_studies
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Prognostic_studies
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Screening_studies
Límite:
Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Aliment Pharmacol Ther
Asunto de la revista:
FARMACOLOGIA
/
GASTROENTEROLOGIA
/
TERAPIA POR MEDICAMENTOS
Año:
2009
Tipo del documento:
Article
Pais de publicación:
Reino Unido