ctDNA动态监测在结直肠癌术后复发风险评估及疗效监测中的临床应用价值：一项单中心 小样本探索性研究

Clinical Application Value of Dynamic ctDNA Monitoring in Postoperative Recurrence Risk Assessment for Colorectal Cancer: A Preliminary Single-Center Study

摘要: 目的：探讨循环肿瘤DNA (ctDNA)动态监测在结直肠癌患者术后微小残留病灶(MRD)识别、复发风险分层及疗效监测中的初步临床应用价值。方法：回顾性分析2021年12月至2023年3月我院收治的11例资料完整的结直肠癌患者临床数据。收集患者术前、术后多时间点的外周血ctDNA检测数据，结合影像学检查(CT/MRI)及临床随访记录，分析ctDNA突变状态与肿瘤复发转移的相关性，评估ctDNA动态变化对疗效及预后的提示作用。结果：回顾性分析11例结直肠癌患者的ctDNA动态监测及临床随访数据，依ctDNA状态分为阴性组5例、阳性组6例。阴性组随访无复发，阳性组均证实存在肿瘤负荷，5例复发/转移、1例经ctDNA指导实现肺微浸润腺癌极早期根治，ctDNA阳性信号较影像学/病理证实中位提前2~4周，两组疾病检出率差异具极显著统计学意义(Fisher确切概率法，P < 0.001)。结论：本单中心小样本探索性研究提示，ctDNA动态监测或可有效识别结直肠癌术后微小残留病灶，其阳性结果对肿瘤复发具有早期预警价值，也能为影像学不明确病灶的临床干预及疗效监测提供分子学参考，KRAS突变或可作为术后复发风险评估的潜在分子标志物。

Abstract: Objective: To investigate the preliminary clinical value of dynamic monitoring of circulating tumor DNA (ctDNA) in the identification of minimal residual disease (MRD), recurrence risk stratification and therapeutic efficacy monitoring in postoperative patients with colorectal cancer. Methods: Clinical data of 11 patients with colorectal cancer with complete information admitted to our hospital from December 2021 to March 2023 were retrospectively analyzed. Peripheral blood ctDNA detection data were collected at multiple time points before and after surgery. Combined with imaging examinations (CT/MRI) and clinical follow-up records, the correlation between ctDNA mutation status and tumor recurrence and metastasis was analyzed, and the predictive role of dynamic ctDNA changes in therapeutic efficacy and prognosis was evaluated. Results: Dynamic ctDNA monitoring and clinical follow-up data of 11 colorectal cancer patients were retrospectively analyzed. According to ctDNA status, the patients were divided into a negative group (5 cases) and a positive group (6 cases). No recurrence was observed in the negative group during follow-up. All patients in the positive group were confirmed to have tumor burden, including 5 cases of recurrence/metastasis and 1 case who achieved very early radical resection of minimally invasive lung adenocarcinoma under the guidance of ctDNA. Positive ctDNA signals were detected a median of 2~4 weeks earlier than confirmation by imaging or pathology. The difference in disease detection rate between the two groups was statistically significant (Fisher’s exact test, P < 0.001). Conclusion: This single-center, small-sample exploratory study suggests that dynamic ctDNA monitoring can effectively identify minimal residual disease after colorectal cancer surgery. A positive ctDNA result has an early warning value for tumor recurrence, and can also provide molecular reference for clinical intervention and efficacy monitoring of lesions unconfirmed by imaging. KRAS mutation may serve as a potential molecular marker for postoperative recurrence risk assessment.