Sorbonne Universités, UPMC Université, Paris; Université Sorbonne Paris Cité, INSERM UMR-S1147 MEPPOT, CNRS SNC5014, Centre Universitaire des Saints-Pères, Equipe Labellisée Ligue Nationale Contre le Cancer, Paris; Department of Hepato-Gastroenterology, Groupe Hospitalier Pitié Salpêtrière, Paris; AGEO (Association des Gastroentérologues Oncologues), Paris.
AGEO (Association des Gastroentérologues Oncologues), Paris; Department of Hepato-Gastroenterology, Hôpital Robert Debré, Reims.
Ann Oncol. 2018 May 1;29(5):1211-1219. doi: 10.1093/annonc/mdy061.
RAS mutations are currently sought for in tumor samples, which takes a median of almost 3 weeks in western European countries. This creates problems in clinical situations that require urgent treatment and for inclusion in therapeutic trials that need RAS status for randomization. Analysis of circulating tumor DNA might help to shorten the time required to determine RAS mutational status before anti-epidermal growth factor receptor antibody therapy for metastatic colorectal cancer. Here we compared plasma with tissue RAS analysis in a large prospective multicenter cohort.
Plasma samples were collected prospectively from chemotherapy-naive patients and analyzed centrally by next-generation sequencing (NGS) with the colon lung cancer V2 Ampliseq panel and by methylation digital PCR (WIF1 and NPY genes). Tumoral RAS status was determined locally, in parallel, according to routine practice. For a minimal κ coefficient of 0.7, reflecting acceptable concordance (precision ± 0.07), with an estimated 5% of non-exploitable data, 425 subjects were necessary.
From July 2015 to December 2016, 425 patients were enrolled. For the 412 patients with available paired plasma and tumor samples, the κ coefficient was 0.71 [95% confidence interval (CI), 0.64-0.77] and accuracy was 85.2% (95% CI, 81.4% to 88.5%). In the 329 patients with detectable ctDNA (at least one mutation or one methylated biomarker), the κ coefficient was 0.89 (95% CI, 0.84-0.94) and accuracy was 94.8% (95% CI, 91.9% to 97.0%). The absence of liver metastases was the main clinical factor associated with inconclusive circulating tumor DNA results [odds ratio = 0.11 (95% CI, 0.06-0.21)]. In patients with liver metastases, accuracy was 93.5% with NGS alone and 97% with NGS plus the methylated biomarkers.
This prospective trial demonstrates excellent concordance between RAS status in plasma and tumor tissue from patients with colorectal cancer and liver metastases, thus validating plasma testing for routine RAS mutation analysis in these patients.
Clinicaltrials.gov, NCT02502656.
目前在西欧国家，肿瘤样本中需要寻找 RAS 突变，中位时间将近 3 周。这在需要紧急治疗的临床情况下以及需要 RAS 状态进行随机分组的治疗试验中造成了问题。循环肿瘤 DNA 的分析可能有助于缩短转移性结直肠癌接受表皮生长因子受体抗体治疗前确定 RAS 突变状态所需的时间。在此，我们在一项大型前瞻性多中心队列中比较了血浆和组织 RAS 分析。
前瞻性采集化疗初治患者的血浆样本，通过下一代测序（NGS）联合结肠肺癌 V2 Ampliseq 试剂盒及甲基化数字 PCR（WIF1 和 NPY 基因）进行中心分析。同时根据常规实践在当地平行确定肿瘤的 RAS 状态。为了达到最小κ系数 0.7，反映可接受的一致性（精度±0.07），并估计有 5%的数据不可用，需要 425 名受试者。
2015 年 7 月至 2016 年 12 月，共纳入 425 名患者。对于 412 名具有可获得的配对血浆和肿瘤样本的患者，κ系数为 0.71[95%置信区间（CI），0.64-0.77]，准确性为 85.2%（95%CI，81.4%至 88.5%）。在 329 名可检测到 ctDNA（至少一个突变或一个甲基化生物标志物）的患者中，κ系数为 0.89（95%CI，0.84-0.94），准确性为 94.8%（95%CI，91.9%至 97.0%）。无肝转移是与循环肿瘤 DNA 结果不确定相关的主要临床因素[比值比=0.11（95%CI，0.06-0.21）]。在有肝转移的患者中，单独使用 NGS 的准确性为 93.5%，而联合使用 NGS 和甲基化生物标志物的准确性为 97%。
这项前瞻性试验证明了结直肠癌和肝转移患者血浆和肿瘤组织中 RAS 状态之间具有极好的一致性，从而验证了在这些患者中进行常规 RAS 突变分析的血浆检测。
Clinicaltrials.gov，NCT02502656。
