Evaluation of novel serological markers for early diagnosis of colorectal neoplasia SID 85

结直肠癌（CRC）是德国最常见的癌症，每年约有70,000例新病例。从理论上讲，每年近30,000例结直肠癌死亡中的大多数可以通过结肠镜检查早期发现和切除腺瘤和早期癌症阶段来预防，结肠镜检查自2007年10月起在德国作为初级筛查检查提供。然而，由于其侵入性和不适，结肠镜筛查的参与率仍然很低，需要补充的，侵入性较小的早期检测方法。现有的替代方法，如粪便隐血检测，敏感性较差，特别是对于腺瘤。最近，一些结肠癌特异性标志物，即结肠癌特异性抗原(CCSA)-2、-3和-4，已被确定，并在初步的小规模研究中具有良好的敏感性和特异性，这些研究大多在临床环境中进行。在这个多中心项目中，将在德国结肠镜筛查项目的2000名参与者中评估这三种标志物（单独或联合）用于早期检测CRC和晚期腺瘤的性能。使用结肠镜检查结果作为金标准，灵敏度和特异性将在预定义的切点确定。关键次要终点包括阳性和阴性预测值、ROC曲线、似然比和需要筛选的数字。

With approximately 70,000 new cases per year, colorectal cancer (CRC) is the most common cancer in Germany. Most of the almost 30,000 CRC deaths per year could, in theory, be prevented by early detection and removal of adenomas and early cancer stages via colonoscopy which is offered as primary screening examination in Germany since October 2007. However, due to its invasiveness and discomfort, participation rates in screening colonoscopy remain low, and complementary, less invasive approaches to early detection are needed. Existing alternatives, such as fecal occult blood testing,suffer from poor sensitivity, especially with respect to adenomas. Recently, several colon cancer-specific markers, denoted colon cancer specific antigen (CCSA)-2, -3, and -4, have been identified and reported to have promising sensitivity and specificity in preliminary small-scale studies mostly conducted in clinical settings. In this multi-center project, performance of the three markers (individually and in combination) for early detection of CRC and advanced adenomas will be evaluated among 2,000 participants of the German colonoscopy screening program. Using findings at colonoscopy as gold standard, sensitivity and specificity will be determined at predefined cutpoints. Key secondary endpoints include positive and negative predictive values, ROC curves, likelihood ratios and numbers needed to screen.