Unit of Cancer Genetics, Institute of Biomolecular Chemistry, National Research Council, Traversa La Crucca 3, 07100, Sassari, Italy.
Department of Medical, Surgical, and Experimental Sciences, University of Sassari, Viale San Pietro 43, 07100, Sassari, Italy.
J Transl Med. 2019 Aug 28;17(1):289. doi: 10.1186/s12967-019-2039-4.
Cutaneous malignant melanoma (CMM) is one of the most common skin cancers worldwide. Limited information is available in the current scientific literature on the concordance of genetic alterations between primary and metastatic CMM. In the present study, we performed next-generation sequencing (NGS) analysis of the main genes participating in melanoma pathogenesis and progression, among paired primary and metastatic lesions of CMM patients, with the aim to evaluate levels of discrepancies in mutational patterns.
Paraffin-embedded tumor tissues of the paired lesions were retrieved from the archives of the institutions participating in the study. NGS was performed using a specific multiple-gene panel constructed by the Italian Melanoma Intergroup (IMI) to explore the mutational status of selected regions (343 amplicons; amplicon range: 125-175 bp; coverage 100%) within the main 25 genes involved in CMM pathogenesis; sequencing was performed with the Ion Torrent PGM System.
A discovery cohort encompassing 30 cases, and a validation cohort including eleven Sardinian patients with tissue availability from both the primary and metachronous metastatic lesions were identified; the global number of analyzed tissue specimens was 90. A total of 829 genetic non-synonymous variants were detected: 101 (12.2%) were pathogenic/likely pathogenic, 131 (15.8%) were benign/likely benign, and the remaining 597 (72%) were uncertain/unknown significance variants. Considering the global cohort, the consistency in pathogenic/pathogenic like mutations was 76%. Consistency for BRAF and NRAS mutations was 95.2% and 85.7% respectively, without statistically significant differences between the discovery and validation cohort.
Our study showed a high level of concordance in mutational patterns between primary and metastatic CMM, especially when pathogenic mutations in driver genes were considered.
皮肤恶性黑色素瘤（CMM）是全球最常见的皮肤癌之一。目前科学文献中关于原发性和转移性 CMM 之间遗传改变的一致性信息有限。在本研究中，我们对 CMM 患者的配对原发性和转移性病变的主要参与黑色素瘤发病机制和进展的基因进行了下一代测序（NGS）分析，旨在评估突变模式差异的程度。
从参与研究的机构档案中检索配对病变的石蜡包埋肿瘤组织。使用意大利黑色素瘤研究组（IMI）构建的特定多基因面板进行 NGS，该面板用于探索选定区域（343 个扩增子；扩增子范围：125-175 bp；覆盖度 100%）内主要 25 个基因的突变状态，这些基因参与 CMM 的发病机制；使用 Ion Torrent PGM 系统进行测序。
确定了一个包含 30 例的发现队列和一个包含 11 例撒丁岛患者的验证队列，这些患者的组织可从原发性和同时性转移性病变中获得；总共分析了 90 个组织标本。共检测到 829 个非同义遗传变异：101 个（12.2%）为致病性/可能致病性，131 个（15.8%）为良性/可能良性，其余 597 个（72%）为不确定/未知意义的变异。考虑到全球队列，致病性/类似致病性突变的一致性为 76%。BRAF 和 NRAS 突变的一致性分别为 95.2%和 85.7%，在发现队列和验证队列之间没有统计学上的显著差异。
我们的研究表明，原发性和转移性 CMM 之间的突变模式具有高度一致性，特别是当考虑到驱动基因中的致病性突变时。
