在局限性结肠癌 (CC) 的情况下，血浆中的循环肿瘤 DNA (ctDNA) 监测显示出检测微小残留病 (MRD) 和预测较高复发风险的潜力。然而，采用仅肿瘤测序方法，种系变异可能会被错误地识别为体细胞变异，由于缺乏已知的体细胞突变，从而排除了对高达 11% 的患者进行追踪的可能性。在这项研究中，我们评估了在肿瘤组织测序中添加白细胞 (WBC) 以提高测序结果准确性的潜在价值。西班牙巴伦西亚临床大学医院前瞻性招募了 148 名诊断为局限性 CC 的患者）。采用定制的 29 基因组，对肿瘤组织、血浆和相应的白细胞进行测序。对术后血浆样本进行微滴式数字 PCR 和基于扩增子的 NGS 来追踪 MRD。通过 COSMIC、OncoKB 和致病突变数据库内部存储库注释来鉴定致癌体细胞变异。进行变体优先分析，主要特征是致癌突变与 OncoKB 中定义的证据水平的匹配，以选择特定的靶向治疗。利用配对肿瘤和白细胞测序，我们在我们的研究范围内的所有患者 (100%) 中发现了体细胞突变。相比之下，89% 的人仅使用肿瘤组织。因此，血浆监测中最常见的 10 个突变基因发生了改变。 WBC 测序发现 9% 的患者存在种系致病性突变，其中 APC 和 TP53 是最常见的突变基因。此外，在 27% 的队列中检测到与不确定潜力克隆造血相关的基因突变，其中 TP53、KRAS 和 KMT2C 是最常改变的基因。使用 ddPCR 或基于扩增子的 NGS 监测 MRD 的敏感性没有观察到差异 (p = 1)。最终，41%的患者在诊断时存在潜在的可针对性的改变。种系检测方法不仅增强了测序结果，提高了符合血浆监测条件的患者比例，而且还发现了致病性种系变异的存在，从而有助于识别患有遗传性癌症综合征风险较高的患者。版权所有 © 2023 作者。由爱思唯尔有限公司出版。保留所有权利。

In the setting of localized colon cancer (CC), circulating tumor DNA (ctDNA) monitoring in plasma has shown potential for detecting minimal residual disease (MRD) and predicting a higher risk of recurrence. With the tumor-only sequencing approach, however, germline variants may be misidentified as somatic variations, precluding the possibility of tracking in up to 11% of patients due to a lack of known somatic mutations. In this study, we assess the potential value of adding white blood cells (WBCs) to tumor tissue sequencing to enhance the accuracy of sequencing results.A total of 148 patients diagnosed with localized CC were prospectively recruited at the Hospital Clínico Universitario in Valencia (Spain). Employing a custom 29-gene panel, sequencing was conducted on tumor tissue, plasma and corresponding WBCs. Droplet digital PCR and amplicon-based NGS were performed on plasma samples post-surgery to track MRD. Oncogenic somatic variants were identified by annotating with COSMIC, OncoKB and an internal repository of pathogenic mutations database. A variant prioritization analysis, mainly characterized by the match of oncogenic mutations with the evidence levels defined in OncoKB, was carried out to select specific targeted therapies.Utilizing paired tumor and WBCs sequencing, we identified somatic mutations in all patients (100%) within our cohort, compared to 89% using only tumor tissue. Consequently, the top 10 most frequently mutated genes for plasma monitoring were altered. The sequencing of WBCs identified 9% of patients with pathogenic mutations in the germline, with APC and TP53 being the most frequently mutated genes. Additionally, mutations in genes related to clonal hematopoiesis of indeterminate potential were detected in 27% of the cohort, with TP53, KRAS, and KMT2C being the most frequently altered genes. There were no observed differences in the sensitivity of monitoring MRD using ddPCR or amplicon-based NGS (p = 1). Ultimately, 41% of the patients harbored potentially targetable alterations at diagnosis.The germline testing method not only enhanced sequencing results and raised the proportion of patients eligible for plasma monitoring, but also uncovered the existence of pathogenic germline variations, thereby aiding in the identification of patients at a higher risk of hereditary cancer syndromes.Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.