Department of Internal Medicine (Di.M.I.), University of Genoa, Viale Benedetto XV, 6, 16132, Genoa, Italy.
Department of Integrated Surgical and Diagnostic Sciences (DISC), University of Genoa, Genoa, Italy.
J Transl Med. 2019 Apr 29;17(1):137. doi: 10.1186/s12967-019-1879-2.
Over the past few years, next-generation sequencing (NGS) has become reliable and cost-effective, and its use in clinical practice has become a reality. A relevant role for NGS is the prediction of response to anti-EGFR agents in metastatic colorectal cancer (mCRC), where multiple exons from KRAS, NRAS, and BRAF must be sequenced simultaneously.
We optimized a 14-amplicon NGS panel to assess, in a consecutive cohort of 219 patients affected by mCRC, the presence and clinico-pathological associations of mutations in the KRAS, NRAS, BRAF, and PIK3CA genes from formalin-fixed, paraffin-embedded specimens collected for diagnostics and research at the time of diagnosis.
We observed a statistically significant association of RAS mutations with sex, young age, and tumor site. We demonstrated that concomitant mutations in the RAS/RAF pathway are not infrequent in mCRC, and as anticipated by whole-genome studies, RAS and PIK3CA tend to be concurrently mutated. We corroborated the association of BRAF mutations in right mCRC tumors with microsatellite instability. We established tumor side as prognostic parameter independently of mutational status.
To our knowledge, this is the first monocentric, consecutively accrued clinical mCRC cancer cohort tested by NGS in a real-world context for KRAS, NRAS, BRAF, and PIK3CA. Our study has highlighted in clinical practice findings such as the concomitance of mutations in the RAS/RAF pathway, the presence of multiple mutations in single gene, the co-occurrence of RAS and PIK3CA mutations, the prognostic value of tumor side and possible associations of sex with specific mutations.
在过去的几年中，下一代测序（NGS）已经变得可靠且具有成本效益，其在临床实践中的应用已成为现实。NGS 的一个相关作用是预测转移性结直肠癌（mCRC）中抗 EGFR 药物的反应，其中必须同时对 KRAS、NRAS 和 BRAF 的多个外显子进行测序。
我们优化了一个 14 个扩增子的 NGS 面板，以评估 219 例连续 mCRC 患者的 KRAS、NRAS、BRAF 和 PIK3CA 基因的突变情况，这些患者的福尔马林固定、石蜡包埋样本是在诊断时为诊断和研究收集的。
我们观察到 RAS 突变与性别、年龄较小和肿瘤部位存在统计学显著关联。我们证明了 RAS/RAF 通路中的伴随突变在 mCRC 中并不罕见，并且正如全基因组研究所预期的那样，RAS 和 PIK3CA 往往同时发生突变。我们证实了右 mCRC 肿瘤中 BRAF 突变与微卫星不稳定性的关联。我们确立了肿瘤侧作为独立于突变状态的预后参数。
据我们所知，这是第一个在真实世界环境中通过 NGS 对 KRAS、NRAS、BRAF 和 PIK3CA 进行测试的单中心、连续累积的临床 mCRC 癌症队列。我们的研究在临床实践中强调了一些发现，例如 RAS/RAF 通路中的突变伴随、单个基因中的多个突变、RAS 和 PIK3CA 突变的共同发生、肿瘤侧的预后价值以及性别与特定突变的可能关联。
