Young Graeme P, Cole Stephen
Flinders Cancer Control Alliance, Flinders University, Adelaide, Australia.
Digestion. 2007;76(1):26-33. doi: 10.1159/000108391. Epub 2007 Oct 19.
BACKGROUND/AIMS: The purpose of this review is to clarify the place of new-technology stool tests in screening for colorectal neoplasia.
New technologies have been based on blood and cellular products of neoplasia. Fecal occult blood tests (FOBTs) based on guaiac (i.e. GFOBTs) have been proved to be effective, but their impact on mortality is modest. When GFOBTs are reconfigured to provide improved sensitivity for cancer, their specificity often becomes unacceptable. Fecal immunochemical tests (FITs) targeting the human hemoglobin molecule have been shown to have better sensitivity for neoplasia without an unacceptable deterioration in specificity. The new stool-sampling technologies for FITs also improve population participation rates in screening. Most recently, quantitative FITs have become available; these provide flexibility for the end-user as a desired sensitivity: specificity ratio can be selected that is feasible in the context of available colonoscopic resources. A multi-target fecal DNA test, comprising a test for undegraded DNA and certain common mutations, was found more sensitive for cancer, but not for adenoma, than the early GFOBTs. A more recent version including an epigenetic marker for the vimentin gene has further improved sensitivity for cancer, but performance relative to GFOBT or FIT is not clear. These 'fecal DNA tests' have not proved to be more specific for neoplasia than tests that detect blood.
FIT should replace GFOBT as the first test in two-step screening of large populations. It is not yet clear that tests targeting nonhemoglobin molecular events provide a clear advantage over FIT.
背景/目的:本综述的目的是阐明新技术粪便检测在结直肠肿瘤筛查中的地位。
新技术基于肿瘤的血液和细胞产物。基于愈创木脂的粪便潜血试验(即GFOBT)已被证明是有效的,但其对死亡率的影响不大。当重新配置GFOBT以提高对癌症的敏感性时,其特异性往往变得不可接受。针对人类血红蛋白分子的粪便免疫化学试验(FIT)已显示出对肿瘤具有更好的敏感性,且特异性没有不可接受的下降。用于FIT的新粪便采样技术也提高了人群筛查参与率。最近,定量FIT已上市;这些产品为终端用户提供了灵活性,因为可以根据可用的结肠镜检查资源选择所需的敏感性:特异性比。与早期的GFOBT相比,一种多靶点粪便DNA检测,包括对未降解DNA和某些常见突变的检测,对癌症更敏感,但对腺瘤不敏感。包括波形蛋白基因表观遗传标记的更新版本进一步提高了对癌症的敏感性,但相对于GFOBT或FIT的性能尚不清楚。这些“粪便DNA检测”尚未被证明比检测血液的试验对肿瘤更具特异性。
在对大量人群进行两步筛查时,FIT应取代GFOBT作为首选检测方法。目前尚不清楚针对非血红蛋白分子事件的检测是否比FIT具有明显优势。