Fecal gene detection based on next generation sequencing for colorectal cancer diagnosis

作     者：Si-Yu He Ying-Chun Li Yong Wang Hai-Lin Peng Cheng-Lin Zhou Chuan-Meng Zhang Sheng-Lan Chen Jian-Feng Yin Mei Lin 

作者机构：Department of Clinical LaboratoryTaizhou People's Hospital(Postgraduate Training Base of Dalian Medical University)Taizhou 225300Jiangsu ProvinceChina Department of Clinical LaboratoryThe First People's Hospital of Tianmen CityTianmen 431700Hubei ProvinceChina Department of General SurgeryTaizhou People's Hospital(Postgraduate Training Base of Dalian Medical University)Taizhou 225300Jiangsu ProvinceChina Central LaboratoryTaizhou People's Hospital(Postgraduate training base of Dalian Medical University)Taizhou 225300Jiangsu ProvinceChina Department of LaboratoryTaizhou Genewill Medical Laboratory Company LimitedTaizhou 225300Jiangsu ProvinceChina Department of LaboratoryJiangsu CoWin Biotech Co.Ltd.Taizhou 225300Jiangsu ProvinceChina 

出 版 物：《World Journal of Gastroenterology》 (世界胃肠病学杂志（英文版）)

年 卷 期：2022年第28卷第25期

页      面：2920-2936页

核心收录：

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

基　　金：Supported by Taizhou Social Development Plan,No.TS202004 Natural Science Foundation of Nanjing University of Chinese Medicine China,No.XZR2020093 Taizhou People's Hospital Medical Innovation Team Foundation,No.CXTDA201901. 

主　　题：Colorectal cancer Feces Next generation sequencing Diagnosis Gene 

摘      要：BACKGROUND Colorectal cancer(CRC)is one of the most common malignancies worldwide.Given its insidious onset,the condition often already progresses to advanced stage when symptoms occur.Thus,early diagnosis is of great significance for timely clinical intervention,efficacy enhancement,and prognostic improvement.Featuring high throughput,fastness,and rich information,next generation sequencing(NGS)can greatly shorten the detection time,which is a widely used detection technique at present.AIM To screen specific genes or gene combinations in fecal DNA that are suitable for diagnosis and prognostic prediction of CRC,and to establish a technological platform for CRC screening,diagnosis,and efficacy monitoring through fecal DNA detection.METHODS NGS was used to sequence the stool DNA of patients with CRC,which were then compared with the genetic testing results of the stool samples of normal controls and patients with benign intestinal disease,as well as the tumor tissues of CRC patients.Specific genes or gene combinations in fecal DNA suitable for diagnosis and prognostic prediction of CRC were screened,and their significances in diagnosing CRC and predicting patients prognosis were comprehensively evaluated.RESULTS High mutation frequencies of TP53,APC,and KRAS were detected in the stools and tumor tissues of CRC patients prior to surgery.Contrastively,no pathogenic mutations of the above three genes were noted in the postoperative stools,the normal controls,or the benign intestinal disease group.This indicates that tumor-specific DNA was detectable in the preoperative stools of CRC patients.The preoperative fecal expression of tumor-associated genes can reflect the gene mutations in tumor tissues to some extent.Compared to the postoperative stools and the stools in the two control groups,the pathogenic mutation frequencies of TP53 and KRAS were significantly higher for the preoperative stools(χ^(2)=7.328,P0.05),so further analysis with larger sample size is required.Among CRC patients,the pathogenic mutation sites of TP53 occurred in 16 of 27 preoperative stools,with a true positive rate of 59.26%,while the pathogenic mutation sites of KRAS occurred in 10 stools,with a true positive rate of 37.04%.The sensitivity and negative predictive values of the combined genetic testing of TP53 and KRAS were 66.67%(18/27)and 68.97%,respectively,both of which were higher than those of TP53 or KRAS mutation detection alone,suggesting that the combined genetic testing can improve the CRC detection rate.The mutation sites TP53 exon 4 A84G and EGFR exon 20 I821T(mutation start and stop positions were both 7579436 for the former,while 55249164 for the latter)were found in the preoperative stools and tumor tissues.Theseundetectedmutation sites may be new types of mutations occurring during the CRC carcinogenesis and progression,which needs to be confirmed through further research.Some mutations ofunknown clinical significancewere found in such genes as TP53,PTEN,KRAS,BRAF,AKT1,and PIK3CA,whose clinical values is worthy of further exploration.CONCLUSION NGS-based fecal genetic testing can be used as a complementary technique for the CRC diagnosis.Fecal TP53 and KRAS can be used as specific genes for the screening,diagnosis,prognostic prediction,and recurrence monitoring of CRC.Moreover,the combined testing of TP53 and KRAS genes can improve the CRC detection rate.