Liu Yi, Zhao Guodong, Miao Jin, Li Hui, Ma Yong, Liu Xiaoyu, Li Shiming, Zhu Yun, Xiong Shangmin, Zheng Minxue, Fei Sujuan
Department of Gastroenterology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China.
Institute of Digestive Diseases, Xuzhou Medical University, Xuzhou, China.
Front Genet. 2020 Apr 16;11:324. doi: 10.3389/fgene.2020.00324. eCollection 2020.
Colorectal cancer (CRC) is the most common type of malignancies of the gastrointestinal tract worldwide. Plasma methylated test has been used clinically for CRC screening for several years, but the study about the performance comparison between plasma and stool has rarely been reported. In this study, 124 plasma samples, 100 stool samples, and 60 sets of plasma and paired stool samples were collected and tested by a methylated test in three PCR replicates. The results indicated methylated levels in stool samples were significant higher than those in plasma samples ( < 0.0001). When a plasma sample was called positive if 1 out of 3 PCR replicates was positive and a stool sample was called positive if 3 out of 3 PCR replicates were positive with a mean Cp value of less than 40.0, stool methylated test achieved similar sensitivity (83.3% vs 85.6%) and specificity (92.1% vs 90.1%) to those by plasma methylated test, and the overall concordance rate is 78.3%. However, stool methylated test showed 35.9 and 7.9% improvement in detecting advanced adenomas (AA) and stage I-II CRC in comparison to plasma methylated test. The AUC for plasma methylated and stool methylated in detecting CRC were 0.885 (95% CI: 0.832-0.938) and 0.935 (95% CI: 0.895-0.975), respectively. In conclusion, stool methylated test showed higher sensitivities for detection AA and early stage CRC compared with plasma methylated SEPT9 test, and stool methylated test may be a more suitable tool for early stage CRC screening.
结直肠癌（CRC）是全球胃肠道最常见的恶性肿瘤类型。血浆甲基化检测已在临床上用于CRC筛查数年，但关于血浆和粪便检测性能比较的研究鲜有报道。本研究收集了124份血浆样本、100份粪便样本以及60组血浆和配对粪便样本，并通过甲基化检测进行了三次PCR重复检测。结果表明，粪便样本中的甲基化水平显著高于血浆样本（P<0.0001）。当3次PCR重复检测中有1次呈阳性时血浆样本判定为阳性，当3次PCR重复检测均呈阳性且平均Cp值小于40.0时粪便样本判定为阳性，粪便甲基化检测与血浆甲基化检测的灵敏度（83.3%对85.6%）和特异性（92.1%对90.1%）相似，总体一致性率为78.3%。然而，与血浆甲基化检测相比，粪便甲基化检测在检测高级别腺瘤（AA）和I-II期CRC方面分别提高了35.9%和7.9%。血浆甲基化检测和粪便甲基化检测在检测CRC中的AUC分别为0.885（95%CI：0.832-0.938）和0.935（95%CI：0.895-0.975）。总之，与血浆甲基化SEPT9检测相比，粪便甲基化检测在检测AA和早期CRC方面显示出更高的灵敏度，粪便甲基化检测可能是更适合早期CRC筛查的工具。
