[Pathological-anatomical diagnosis according to the German lung cancer guideline 2018]

[Molecular cytology: Opportunities and challenges]

Predictive marker (re-)analysis of tumor material can be a real obstacle in several tumor entities, like non-small cell lung cancer (NSCLC), due to difficult anatomic conditions and small biopsy samples. As reported in the literature, cytological samples comprise excellent starting material for predictive marker analysis like fluorescence in situ hybridization and next generation sequencing. As for formalin-fixed paraffin-embedded tissue samples, rigorous quality control and standardized laboratory operating procedures are mandatory. Further advantages of cytological specimens are the rapid and straightforward inspection of representativeness, for example by rapid on-site evaluation (ROSE). Another striking advantage is that the fresh cellular material from smears and serous cavity fluids can be used for the generation of two- and three-dimensional cell culture models. Hereby, in addition to the conventional biomarker testing, complex complementary functional genomic assays can also be applied, for example, to assess the effects of multiple variants in one sample and unknown variants of tumor driver genes and tumor suppressor genes. This information may provide additional vulnerabilities of the tumor to be considered for the therapy decision, for example in the molecular tumor board.

Predictive molecular pathology of lung cancer in Germany with focus on gene fusion testing: Methods and quality assurance

Predictive molecular testing has become an important part of the diagnosis of any patient with lung cancer. Using reliable methods to ensure timely and accurate results is inevitable for guiding treatment decisions. In the past few years, parallel sequencing has been established for mutation testing, and its use is currently broadened for the detection of other genetic alterations, such as gene fusion and copy number variations. In addition, conventional methods such as immunohistochemistry and in situ hybridization are still being used, either for formalin-fixed, paraffin-embedded tissue or for cytological specimens. For the development and broad implementation of such complex technologies, interdisciplinary and regional networks are needed. The Network Genomic Medicine (NGM) has served as a model of centralized testing and decentralized treatment of patients and incorporates all German comprehensive cancer centers. Internal quality control, laboratory accreditation, and participation in external quality assessment is mandatory for the delivery of reliable results. Here, we provide a summary of current technologies used to identify patients who have lung cancer with gene fusions, briefly describe the structures of NGM and the national NGM (nNGM), and provide recommendations for quality assurance.

[Immunohistochemical and molecular pathological diagnosis of lung carcinoma]

The therapy of lung cancer has revolutionarily changed within the last 15 years. The prognosis of patients has dramatically improved due to targeted therapies, for instance tyrosine kinase inhibitors (TKI). Current recruiting studies are testing new MET-, KRAS-, ROS1-, RET- and NTRK-inhibitors. The first clinical data are promising, emphasizing that it remains a future challenge for pathologists and oncologists to keep an eye on all facets of therapy options. Today, precise lung cancer classification via immunohistochemistry and molecular pathology is crucial for the therapy and prognosis of patients. Further, new biopsy technologies lead to very small tumor tissue samples and cytological samples of high diagnostic quality. Therefore, the complexity of diagnosis needs a strategic procedure to minimize loss of tissue material. This assay gives an overview of efficient and target-orientated diagnostic procedures in consideration of current clinical trials.

RNA-Based Detection of Gene Fusions in Formalin-Fixed and Paraffin-Embedded Solid Cancer Samples

Oncogenic gene fusions are important drivers in many cancer types, including carcinomas, with diagnostic and therapeutic implications. Hence, sensitive and rapid methods for parallel profiling in formalin-fixed and paraffin-embedded (FFPE) specimens are needed. In this study we analyzed gene fusions in a cohort of 517 cases where standard treatment options were exhausted. To this end the Archer^® DX Solid tumor panel (AMP; 285 cases) and the Oncomine Comprehensive Assay v3 (OCA; 232 cases) were employed. Findings were validated by Sanger sequencing, fluorescence in situ hybridization (FISH) or immunohistochemistry. Both assays demonstrated minimal dropout rates (AMP: 2.4%; n = 7/292, OCA: 2.1%; n = 5/237) with turnaround times of 6-9 working days (median, OCA and AMP, respectively). Hands-on-time for library preparation was 6 h (AMP) and 2 h (OCA). We detected n = 40 fusion-positive cases (7.7%) with TMPRSS2::ERG in prostate cancer being most prevalent (n = 9/40; 22.5%), followed by other gene fusions identified in cancers of unknown primary (n = 6/40; 15.0%), adenoid cystic carcinoma (n = 7/40; 17.5%), and pancreatic cancer (n = 7/40; 17.5%). Our results demonstrate that targeted RNA-sequencing of FFPE samples is feasible, and a well-suited approach for the detection of gene fusions in a routine clinical setting.

[Immunophenotyping of lung tumors : An update]

The WHO Classification of Lung Tumors (2015) established the use of immunohistochemical stainings for resection specimens, however, detailed recommendations had been missing. Now, an international expert panel has summarized key questions for daily routine practice and provided recommendations to assist the community in the appropriate use of immunohistochemistry in this context. This article provides an overview of the most important aspects.