Division of Thoracic Diseases, Chiba Cancer Center, Chiba, Japan.
Clin Cancer Res. 2010 Oct 15;16(20):4938-45. doi: 10.1158/1078-0432.CCR-10-0099. Epub 2010 Oct 5.
Anaplastic lymphoma kinase (ALK) fusion genes represent novel oncogenes for non-small cell lung cancers (NSCLC). Several ALK inhibitors have been developed, and are now being evaluated in ALK-positive NSCLC. The feasibility of detecting ALK fusion genes in samples obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was determined. The clinicopathologic characteristics of ALK-positive lung cancer were also analyzed.
From April 2008 to July 2009, NSCLC cases with hilar/mediastinal lymph node metastases detected by EBUS-TBNA were enrolled. Positive expression of ALK fusion protein was determined using immunohistochemistry, and ALK gene rearrangements were further examined to verify the translocation between ALK and partner genes using fluorescent in situ hybridization and reverse transcription-PCR. Direct sequencing of PCR products was performed to identify ALK fusion variants.
One hundred and nine cases were eligible for the analysis using re-sliced samples. Screening of these specimens with immunohistochemistry revealed ALK positivity in seven cases (6.4%), all of which possessed echinoderm microtubule-associated protein-like 4-ALK fusion genes as detected by fluorescent in situ hybridization and reverse transcription-PCR. All ALK-positive cases had an adenocarcinoma histology and possessed no EGFR mutations. Compared with ALK-negative cases, ALK-positive cases were more likely to have smaller primary tumors (P < 0.05), to occur at a younger age (<60 years; P < 0.05), and to occur in never/light smokers (smoking index < 400; P < 0.01). Mucin production was frequently observed in ALK-positive adenocarcinomas (29.4%; P < 0.01).
EBUS-TBNA is a practical and feasible method for obtaining tissue from mediastinal and hilar lymph nodes that can be subjected to multimodal analysis of ALK fusion genes in NSCLC.
间变性淋巴瘤激酶（ALK）融合基因是一种非小细胞肺癌（NSCLC）的新型致癌基因。已经开发了几种ALK 抑制剂，目前正在对ALK 阳性 NSCLC 进行评估。本研究旨在确定经支气管超声内镜引导经支气管针吸活检（EBUS-TBNA）获得的样本中检测 ALK 融合基因的可行性，并分析ALK 阳性肺癌的临床病理特征。
从 2008 年 4 月至 2009 年 7 月，我们纳入了经 EBUS-TBNA 检测到肺门/纵隔淋巴结转移的 NSCLC 病例。使用免疫组织化学法检测 ALK 融合蛋白的阳性表达，进一步使用荧光原位杂交和逆转录-PCR 检测 ALK 基因重排，以验证 ALK 与伙伴基因之间的易位。通过 PCR 产物的直接测序来鉴定 ALK 融合变体。
用重新切片的样本对 109 例进行了分析。免疫组化筛查发现 7 例（6.4%）为 ALK 阳性，所有病例均通过荧光原位杂交和逆转录-PCR 检测到棘皮动物微管相关蛋白样 4-ALK 融合基因。所有 ALK 阳性病例均为腺癌组织学，且均无 EGFR 突变。与 ALK 阴性病例相比，ALK 阳性病例的原发肿瘤较小（P < 0.05），年龄较轻（<60 岁；P < 0.05），且从不吸烟/吸烟较轻（吸烟指数<400；P < 0.01）。ALK 阳性腺癌中经常观察到粘蛋白产生（29.4%；P < 0.01）。
EBUS-TBNA 是一种实用且可行的方法，可从纵隔和肺门淋巴结获取组织，对 NSCLC 中 ALK 融合基因进行多模式分析。
