A Multicenter Clinical Study Of Stool Dna Test Of Methylated Syndecan-2 For Colorectal Cancer Detection

Study purpose: Previously, we had a pilot study to evaluate the feasibility of a stool DNA test of methylated Syndycan-2 (SDC2) for colorectal cancer (CRC) detection. The purpose of this continuing investigation was to assess the performance of this test in a multicenter hospital-based setting. Methods: Each participant was required to undergo both a stool DNA test and a reference colonoscopy. The stool DNA test assesses the methylation status of a single target of SDC2 gene. Results of real-time methylation-specific PCR were dichotomized as positive and negative by a prespecified cut-off value. The main evaluation indexes were sensitivity, specificity, and kappa value, which was used to assess the diagnostic consistency between stool DNA test and colonoscopy. Tests were performed in blinded fashion and processed independently of the colonoscopic results. Results: Among the 1110 participants from three hospitals included for analysis, 359 and 38 had CRC and advanced adenomas, respectively, according to colonoscopy findings. The sensitivity of the stool DNA test was 83.8% for CRC and 42.1% for advanced adenomas. For CRC at early stage confined to bowel wall (I to II), the sensitivity was 87.0%. Detection rate for CRC did not vary significantly according to age, tumor location, differentiation, and TNM stage, except for gender (P=0.041). The specificity of the stool DNA test was 98.0% among participants with nonadvanced colorectal neoplasia, non-neoplastic disorders, or negative results on colonoscopy. Diagnostic consistency for CRC assessed by kappa value was 0.84, indicating that the agreement in outcome between the stool DNA test and colonoscopy was excellent. Conclusion: Noninvasive stool DNA test using methylated SDC2 as a molecular marker was a sensitive and accurate method for CRC detection. Citation Format: Jianping Wang, Side Liu, Hui Wang, Lei Zheng, Changchun Zhou, Guoxin Li, Rongkang Huang, Huaiming Wang, Chujun Li, Xinjuan Fan, Xinhui Fu, Xinying Wang, Hongliang Guo, Jie Guan, Yanlai Sun, Xilin Song, Zengjun Li, Dianbin Mu, Jujie Sun, Xianglin Liu, Yan Qi, Feng Niu, Chunhua Chen, Xiaolin Wu, Xianshu Wang, Xianrang Song, Hongzhi Zou. A multicenter clinical study of stool DNA test of methylated syndecan-2 for colorectal cancer detection [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4611.