Detection of KRAS Mutations in Circulating Tumor DNA by Digital PCR in Early Stages of Pancreatic Cancer
Detection of KRAS Mutations in Circulating Tumor DNA by Digital PCR in Early Stages of Pancreatic Cancer
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DOI：
10.1373/clinchem.2016.257469
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发表时间：
2016-11-01
影响因子：
9.3
通讯作者：
von Ahsenh, Oliver
中科院分区：
文献类型：
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作者：
Brychta, Nora;Krahn, Thomas;von Ahsenh, Oliver
背景：由于手术切除仍然是胰腺癌的唯一治疗方法，因此早期发现至关重要。循环生物标志物有潜力作为胰腺癌的诊断工具，胰腺癌通常仅在晚期才会引起临床症状。由于 KRAS 原癌基因、GTPase [KRAS（以前的名称：Kirsten 大鼠肉瘤病毒癌基因同源物）] 突变在胰腺癌中发病率很高，因此可用于鉴定肿瘤来源的循环血浆 DNA。在这里，我们测试了基于芯片的数字 PCR 检测早期胰腺癌循环肿瘤 DNA (ctDNA) 中 KRAS 突变的诊断灵敏度。方法：我们分析了 50 名胰腺癌患者的匹配血浆 (2 mL) 和肿瘤样本。该队列中早期阶段（I 和 II）占主导地位（41/50）。从肿瘤和血浆样本中提取 DNA，并通过基于芯片的数字 PCR 检测常见密码子 12 突变 G12D、G12V 和 G12C。 结果：我们在 72% 的肿瘤中发现了 KRAS 突变。 44%的肿瘤对G12D呈阳性，20%对G12V呈阳性，10%对G12C呈阳性。一个肿瘤的 G12D 和 G 12V 呈阳性。对匹配血浆样本中突变的分析显示，G12D 的检出率为 36%，G12V 的检出率为 50%，G12C 的检出率为 0%。该检测似乎与原发肿瘤中的肿瘤细胞总数相关。在 20 个健康对照血浆样本中未检测到 KRAS 突变。 结论：我们的结果支持使用血浆样本作为液体活检来进一步评估肿瘤特异性突变作为早期诊断生物标志物。 (C) 2016年美国临床化学协会
BACKGROUND: Since surgical removal remains the only cure for pancreatic cancer, early detection is of utmost importance. Circulating biomarkers have potential as diagnostic tool for pancreatic cancer, which typically causes clinical symptoms only in advanced stage. Because of their high prevalence in pancreatic cancer, KRAS protooncogene, GTPase [KRAS (previous name: Kirsten rat sarcoma viral oncogene homolog)] mutations may be used to identify tumor-derived circulating plasma DNA. Here we tested the diagnostic sensitivity of chip based digital PCR for the detection of KRAS mutations in circulating tumor DNA (ctDNA) in early stage pancreatic cancer.METHODS: We analyzed matched plasma (2 mL) and tumor samples from 50 patients with pancreatic cancer. Early stages (I and II) were predominant (41/50) in this cohort. DNA was extracted from tumor and plasma samples and tested for the common codon 12 mutations G12D, G12V, and G12C by chip-based digital PCR.RESULTS: We identified KRAS mutations in 72% of the tumors. 44% of the tumors were positive for Gl2D, 20% for G12V, and 10% for G12C. One tumor was positive for G12D and G 12V. Analysis of the mutations in matched plasma samples revealed detection rates of 36% for G12D, 50% for G12V, and 0% for G12C. The detection appeared to be correlated with total number of tumor cells in the primary tumor. No KRAS mutations were detected in 20 samples of healthy control plasma.CONCLUSIONS: Our results support further evaluation of tumor specific mutations as early diagnostic biomarkers using plasma samples as liquid biopsy. (C) 2016 American Association for Clinical Chemistry