Can Next-generation Sequencing Replace Fecal Immunochemical Tests or CT in the Screening of Colorectal Cancer and...

To explore the feasibility of next-generation sequencing (NGS) for the screening of colorectal cancer (CRC) and advanced adenoma (AA).

Observational study. Place and Duration of the Study: Renmin Hospital of Wuhan University, Wuhan, China, from June 2019 to February 2020.

Patients who met inclusion and exclusion criteria were divided into three groups: CRC, AA, and control group. Then, the gene methylation status in the blood in the CRC, AA, and control group was analysed by NGS, and the CRC screening risk assessment model was used for comprehensive analysis. Afterwards, the methylated haplotype index (PHF Index) was calculated, and the screening results of the patients were classified as positive or negative, according to the score. The clinicopathological results were used as the gold standard, and the screening results for NGS were compared with the computed tomography (CT) and fecal immunochemical test (FIT) to text its feasibility.

NGS has a certain detection ability for CRC, with a sensitivity of 57.1% (8/14). This was higher than that of FIT and CT, and the combined positive rate of these three methods could reach 92.3% (12/13). The sensitivity of detection of AA could reach up to 75.0% (6/8) after combining with FIT and CT. The positive rate of the NGS test for postoperative CRC was 23.1% (3/13), which was significantly lower than preoperative CRC. The sensitivity of CT for preoperative CRC detection was only 45.5% (5/11), but the specificity could reach up to 98.2% (55/56), which was higher than NGS (71/78, 91.0%) and FIT (27/33, 81.8%).

Although NGS cannot replace FIT and CT at present, this provides a new effective and auxiliary detection method for people who are unsuitable or unwilling to receive colonoscopy. Key Words: Colorectal neoplasms, Adenoma, High-throughput nucleotide sequencing, Mass screening, Fecal immunochemical tests, Computed tomography.