RT Journal Article SR Electronic T1 Lynch syndrome pre-screening and comprehensive characterization in a multi-center large cohort of Chinese patients with colorectal cancer JF Cancer Biology & Medicine JO Cancer Biology & Medicine FD China Anti-Cancer Association SP 20210585 DO 10.20892/j.issn.2095-3941.2021.0585 A1 Yan Li A1 Lihong Fan A1 Jianming Zheng A1 Xiu Nie A1 Yu Sun A1 Qin Feng A1 Shenyi Lian A1 Wenqi Bai A1 Weijing Cai A1 Yanan Yang A1 Bo Su A1 Yanfeng Xi A1 Dongmei Lin YR 2022 UL http://www.cancerbiomed.org/content/early/2022/07/15/j.issn.2095-3941.2021.0585.abstract AB Objective: Lynch syndrome (LS) pre-screening methods remain under-investigated in colorectal cancers (CRCs) in Asia. Here, we aimed to systematically investigate LS pre-screening and comprehensively characterize LS CRCs.Methods: Microsatellite instability (MSI) and germline variants of DNA mismatch repair (MMR) genes were examined in 406 deficient MMR (dMMR) and 250 proficient MMR CRCs. The genetic differences between LS and sporadic CRCs were studied with whole exome sequencing analysis.Results: The incidence of dMMR in Chinese patients with CRCs was 13.8%. Consistency analysis between MMR immunohistochemistry (IHC) and MSI testing showed the kappa value was 0.758. With next-generation sequencing (NGS), germline variants were detected in 154 CRCs. Finally, 88 patients with CRC were identified as having LS by Sanger sequencing. Among them, we discovered 21 previously unreported pathogenic germline variants of MMR genes. Chinese patients with LS, compared with sporadic CRCs, tended to be early-onset, right-sided, early-stage and mucinous. Overall, the performance of MMR IHC and MSI testing for LS pre-screening was comparable: the area under the ROC curve for dMMR, MSI-H, and MSI-H/L was 0.725, 0.750, and 0.745, respectively. dMMR_MSI-H LS and sporadic CRCs showed substantial differences in somatic genetic characteristics, including different variant frequencies of APC, CREBBP, and KRAS, as well as different enriched pathways of VEGF, Notch, TGFβR, mTOR, ErbB, and Rac protein signal transduction.Conclusions: MMR IHC and MSI testing were effective methods for LS pre-screening. The revealed clinical and somatic genetic characteristics in LS CRCs may have the potential to improve the performance of LS pre-screening in combination with dMMR/MSI.