Fassunke Jana, Ball Markus, Engels Marianne
Institut für Pathologie, Universitätsklinikum Köln, Kerpener Str. 62, 50924, Köln, Deutschland.
Pathologe. 2020 Feb;41(1):39-45. doi: 10.1007/s00292-019-00733-3.
For lung carcinomas with certain molecular genetic alterations of the ALK, BRAF or EGFR gene, there are targeted therapies that are also approved as first-line therapy. Often, only limited sample material from biopsies is available for molecular pathological testing. In some cases, biopsies with standard and immunohistochemical staining have no or too low tumor content to be used for PCR-based examinations or fluorescence in situ hybridization (FISH) analyses. In such cases, cytological preparations such as bronchus brush smears, transbronchial needle aspiration (TBNA), bronchial lavage, puncture smears from lymph node or peripheral metastases, pleural effusion, ascites, and pericardial effusion can be used. Standard stainings such as HE, Pappenheim, and Papanicolaou as well as immunohistological preparations can be used after morphological analysis and confirmatory diagnosis in order to extract DNA from them or to use them for FISH analysis. A cytopathologist marks the tumor cell areas on the slide beforehand. It is only possible to dissect these areas and extract DNA if the proportion of tumor cells is sufficiently high. In order to carry out a FISH analysis with the cytological preparations, the cytopathologist must draw in areas as small as possible with more than 100 tumor cells. Already stained sections are destained before the hybridization reaction. The aim is to achieve comprehensive diagnostics even with limited starting material and to avoid re-biopsies. Between 2016 and July 2019, 1711 next generation sequencing (NGS) and FISH analyses were performed on cytological preparations at the Department of Pathology of the University Hospital of Cologne. The success rate of 85.9% for NGS examinations was slightly higher than the success rate of 82.8% for FISH analyses.
对于具有ALK、BRAF或EGFR基因特定分子遗传学改变的肺癌，有一些靶向治疗药物也被批准作为一线治疗药物。通常，活检获得的样本材料有限，只能用于分子病理学检测。在某些情况下，进行标准染色和免疫组织化学染色的活检样本中肿瘤含量极低或没有肿瘤，无法用于基于PCR的检测或荧光原位杂交（FISH）分析。在这种情况下，可以使用细胞学标本，如支气管刷片、经支气管针吸活检（TBNA）、支气管灌洗、淋巴结或外周转移灶穿刺涂片、胸腔积液、腹水和心包积液。在进行形态学分析和确诊后，可使用苏木精-伊红染色（HE）、帕彭海姆染色和巴氏染色等标准染色以及免疫组织学标本，从中提取DNA或用于FISH分析。细胞病理学家会事先在载玻片上标记出肿瘤细胞区域。只有当肿瘤细胞比例足够高时，才有可能分离这些区域并提取DNA。为了对细胞学标本进行FISH分析，细胞病理学家必须圈出尽可能小的、含有100多个肿瘤细胞的区域。在杂交反应之前，需对已染色的切片进行脱色处理。目的是即使在起始材料有限的情况下也能实现全面诊断，并避免再次活检。2016年至2019年7月期间，科隆大学医院病理科对细胞学标本进行了1711次二代测序（NGS）和FISH分析。NGS检测的成功率为85.9%，略高于FISH分析82.8%的成功率。
