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
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
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DOI：
10.1111/j.1365-2036.2009.03946.x
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发表时间：
2009-04-15
影响因子：
7.6
通讯作者：
Niv, Y.
中科院分区：
文献类型：
--
作者：
Rozen, P.;Levi, Z.;Niv, Y.
粪便潜血试验(FOBT)对晚期腺瘤性息肉(AAP)的敏感性较低。定量的、免疫化学的、血红蛋白(Hb)特异的免疫化学FOBT(I-FOBT)现在被用于结直肠筛查。为了将腺瘤特征与粪便Hb丢失量相关联，并通过粪便Hb的发展阈值和收集的I-FOBT的数量来评估AAP的敏感性和特异性。粪便Hb被分析为缓冲液中的ngHb/ml，与结肠镜检查结果相关的结果最高。在1204名非癌症患者中，结肠镜检查发现294例腺瘤，99例AAPS。腺瘤患者的粪便Hb升高，组织学、大小、带蒂形态和多样性均较高(P<；0.001)。以50ngHb/mL为临界值，AAPS三项检测的敏感性和特异性分别为54.5%(95%CI 44.7，64.7)和88.1%(95%CI 86.2，90.1)。阈值越高，灵敏度越低，但采集的样本越多，灵敏度越高。相反，特异性在更高的阈值下增加，但随着样本的增加而降低。腺瘤的等量Hb丢失与大小、数量和进展性特征显著相关。AAPS的敏感性和特异性取决于选择的检测阈值和采集的样本数量；这些决定了阳性检测所需的结肠镜检查数量。
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.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.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.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.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.