Subungual melanoma (SUM) is a rare type of malignant melanoma that arises beneath the nails. SUM is categorized as a type of acral melanoma (AM), which occurs on the hands and feet. SUM is an aggressive type of cutaneous melanoma that is most common among Asian patients. Recent studies reveal that SUM and AM might have different molecular characteristics. Treatment of melanoma relies on analysis of both clinical and molecular data. Therefore, the clinical and molecular characteristics of SUM need to be established, especially during metastasis. To define the mutation profiles of SUM and compare them with those of AM, we performed next-generation sequencing of primary and metastatic tumors of SUM and AM patients. Subungual location was a better independent prognostic factor than acral location for better overall survival (p= 0.001). Patients with SUM most commonly had the triple wild-type (75%) driven byGNAQ(58%) andKIT(25%) mutations, whereas patients with AM hadBRAF(28.6%) andRAF(14.3%) molecular types of mutations. Single-nucleotide variations (SNVs) were more common in SUM than in AM, whereas copy number alterations (CNAs) were more common metastatic lesions of AM. Metastatic tumors in patients with SUM and AM showed increases in CNAs (43% and 80%, respectively), but not in SNVs. The number of CNAs increased during metastasis. When compared with AM, SUM has distinct clinical and molecular characteristics.
甲下黑色素瘤（SUM）是一种罕见的恶性黑色素瘤亚型，起源于甲床下方。该疾病被归类为肢端型黑色素瘤（AM）的一种，后者好发于手足部位。作为侵袭性皮肤黑色素瘤的特殊类型，SUM在亚洲患者群体中最为常见。最新研究表明，SUM与AM可能具有不同的分子特征。黑色素瘤的治疗需结合临床与分子数据综合分析，因此明确SUM（尤其是转移阶段）的临床与分子特征至关重要。为界定SUM的突变谱并与AM进行对比，本研究对SUM与AM患者的原发灶及转移灶进行了新一代测序分析。 研究显示，甲下病灶是较肢端病灶更具独立性的预后良好因素（总生存期更优，p=0.001）。SUM患者最常见的是由GNAQ（58%）和KIT（25%）突变驱动的三野生型（75%），而AM患者则以BRAF（28.6%）和RAF（14.3%）突变类型为主。单核苷酸变异（SNVs）在SUM中较AM更为常见，而拷贝数变异（CNAs）在AM转移灶中更为普遍。SUM与AM患者的转移性肿瘤均显示CNAs增加（分别为43%和80%），但SNVs未见同步增加。转移过程中CNAs数量呈现上升趋势。与AM相比，SUM具有独特的临床与分子特征。
肿瘤(癌症)患者之家