Kothari Nishi, Schell Michael J, Teer Jamie K, Yeatman Timothy, Shibata David, Kim Richard
J Clin Pathol. 2014 Sep;67(9):764-7. doi: 10.1136/jclinpath-2014-202405.
Based on KRAS testing, the subset of patients with metastatic colorectal cancer (CRC) that could benefit from anti-EGFR therapy can be better delineated. Though KRAS testing has become significantly more prevalent over the last few years, methods for testing remain heterogeneous and discordance has been reported between methods.
In this study, we examined a CRC patient population and compared KRAS testing done in Clinical Laboratory Improvement Amendments (CLIA) approved laboratories as part of standard clinical care and by next-generation sequencing (NGS) using the Illumina platform. Discordances were further evaluated with manual review of the NGS testing.
Out of 468 CRC patient samples, 77 had KRAS testing done by both CLIA assay and NGS. There were concordant results between testing methodologies in 74 out of 77 patients, or 96% (95% CI 89% to 99%). There were three patient samples that showed discordant results between the two methods of testing. Upon further investigation of the NGS results for the three discordant cases, one sample showed a low level of the mutation seen in the standard testing, one sample showed low tumour fraction and a third did not show any evidence of the mutation that was found with the standard assay. Five patients had KRAS mutations not typically tested with standard testing.
Overall there was a high concordance rate between NGS and standard testing for KRAS. However, NGS revealed mutations that are not tested for with standard KRAS assays that might have clinical impact with regards to the role for anti-EGFR therapy.
基于KRAS检测，可更好地界定能从抗表皮生长因子受体（EGFR）治疗中获益的转移性结直肠癌（CRC）患者亚组。尽管在过去几年中KRAS检测已变得更为普遍，但检测方法仍存在异质性，且已报道不同方法之间存在不一致性。
在本研究中，我们检测了一组CRC患者群体，并比较了在临床实验室改进修正案（CLIA）认可的实验室作为标准临床护理的一部分所进行的KRAS检测，以及使用Illumina平台通过下一代测序（NGS）进行的检测。通过对NGS检测进行人工复查进一步评估不一致性。
在468例CRC患者样本中，77例同时进行了CLIA检测和NGS的KRAS检测。77例患者中有74例检测方法之间结果一致，即96%（95%可信区间89%至99%）。有3例患者样本在两种检测方法之间显示出不一致的结果。对这3例不一致病例的NGS结果进行进一步调查后，1个样本显示在标准检测中看到的突变水平较低，1个样本显示肿瘤分数较低，第3个样本未显示出标准检测中发现的任何突变证据。5例患者具有标准检测通常未检测的KRAS突变。
总体而言，NGS与KRAS标准检测之间的一致性率较高。然而，NGS揭示了标准KRAS检测未检测的突变，这些突变可能对抗EGFR治疗的作用具有临床影响。
