Hepatobiliary system cancers have demonstrated an increasing incidence rate in the past years. Without the presence of early symptoms, the majority of such cancers manifest with a set of similar symptoms, such as cholestasis resulting in posthepatic icterus. Differential diagnosis of hepatobiliary cancers is required for the therapy selection, however, the similarity of the symptoms complicates diagnostics. Thus, the search for molecular markers is of high interest for such patients. Cholangiocarcinoma (CCA) is characterized by a poor prognosis due to a low resectability rate, which occurs because this disease is frequently beyond the limits of surgical therapy at the time of diagnosis. The CCA is diagnosed by the combination of clinical/biochemical features, radiological methods, and non-specific serum tumor biomarkers, although invasive examination is still needed. The main disadvantage is limited specificity and sensitivity, which complicates early diagnostics. Therefore, prognostic and predictive biomarkers are still lacking and urgently needed for early diagnosis. In contrast to serum, bile is more accessible to identify biliary disease due to its simpler composition. Moreover, bile can contain higher concentrations of tumor biomarkers due to its direct contact with the tumor. It is known that the composition of the main bile component - bile acids, may vary during different diseases of the biliary tract. This review summarizes the recent developments in the current research on the diagnostic biomarkers for CCA in serum and bile and provides an overview of the methods of bile acids analysis.

中文翻译：

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胆管癌的分子生物标志物：关注胆汁

近年来，肝胆系统癌症的发病率不断上升。在不存在早期症状的情况下，大多数此类癌症都会表现出一系列类似的症状，例如导致肝后黄疸的胆汁淤积。选择治疗方法需要对肝胆癌进行鉴别诊断，但症状的相似性使诊断变得复杂。因此，寻找分子标记对于此类患者来说非常重要。胆管癌（CCA）的特点是由于可切除率低而导致预后不良，这是因为这种疾病在诊断时经常超出手术治疗的限度。尽管仍需要侵入性检查，但 CCA 的诊断需结合临床/生化特征、放射学方法和非特异性血清肿瘤生物标志物。主要缺点是特异性和敏感性有限，这使早期诊断变得复杂。因此，预后和预测生物标志物仍然缺乏且迫切需要用于早期诊断。与血清相比，胆汁由于其成分更简单，更容易识别胆道疾病。此外，由于胆汁与肿瘤直接接触，胆汁可能含有更高浓度的肿瘤生物标志物。众所周知，胆汁的主要成分——胆汁酸的组成在不同的胆道疾病期间可能会有所不同。本文总结了血清和胆汁中 CCA 诊断生物标志物的最新研究进展，并对胆汁酸分析方法进行了概述。