Detection of ALK-positive non-small-cell lung cancers on cytological specimens: high accuracy of immunocytochemistry with the 5A4 clone

Concordance of Immunohistochemistry and Fluorescence In Situ Hybridization in the Detection of Anaplastic Lymphoma Kinase (ALK) and Ros Proto-oncogene 1 (ROS1) Gene Rearrangements in Non-Small Cell Lung Carcinoma: A 4.5-Year Experience Highlighting Challenges and Pitfalls

CONTEXT.—

ALK and ROS1 rearrangements are essential biomarkers to be tested in advanced lung adenocarcinomas. While D5F3 Ventana assay is a companion diagnostic for anaplastic lymphoma kinase-targeted therapy, immunohistochemistry is only a screening tool for detecting ROS1 rearrangement. Confirmation by cytogenetic or molecular techniques is necessary.

OBJECTIVE.—

To evaluate the utility of ALK and ROS1 fluorescence in situ hybridization as a complement to immunohistochemistry in routine predictive biomarker testing algorithms.

DESIGN.—

The study was ambispective, spanning 4.5 years during which lung adenocarcinoma samples were subjected to EGFR mutation testing by real-time polymerase chain reaction and ALK/ROS1 rearrangement testing by immunohistochemistry (Ventana D5F3 assay for anaplastic lymphoma kinase protein; manual assay with D4D6 clone for Ros proto-oncogene 1 protein). Fluorescence in situ hybridization was performed in all anaplastic lymphoma kinase equivocal and Ros proto-oncogene 1 immunopositive cases.

RESULTS.—

Of 1874 samples included, EGFR mutations were detected in 27% (481 of 1796). Anaplastic lymphoma kinase immunohistochemistry was positive in 10% (174 of 1719) and equivocal in 3% (58 of 1719) of samples tested. ALK fluorescence in situ hybridization showed 81% (77 of 95) concordance with immunohistochemistry. Ros proto-oncogene 1 immunopositivity was noted in 13% (190 of 1425) of cases, with hybridization-confirmed rearrangements in 19.3% (26 of 135) of samples, all of which showed diffuse, strong- to moderate-intensity, cytoplasmic staining in tumor cells. Ros proto-oncogene 1 protein overexpression without rearrangement was significantly common in EGFR-mutant and ALK-rearranged adenocarcinomas.

CONCLUSIONS.—

Immunostaining is a robust method for ALK-rearrangement testing, with fluorescence in situ hybridization adding value in the rare equivocal stained case. ROS1-rearrangement testing is more cost-effective if immunohistochemistry is followed by fluorescence in situ hybridization after excluding EGFR-mutant and ALK-rearranged adenocarcinomas.

Principles of Analytic Validation of Immunohistochemical Assays: Guideline Update

CONTEXT.—

In 2014, the College of American Pathologists developed an evidence-based guideline to address analytic validation of immunohistochemical assays. Fourteen recommendations were offered. Per the National Academy of Medicine standards for developing trustworthy guidelines, guidelines should be updated when new evidence suggests modifications.

OBJECTIVE.—

To assess evidence published since the release of the original guideline and develop updated evidence-based recommendations.

DESIGN.—

The College of American Pathologists convened an expert panel to perform a systematic review of the literature and update the original guideline recommendations using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS.—

Two strong recommendations, 1 conditional recommendation, and 12 good practice statements are offered in this updated guideline. They address analytic validation or verification of predictive and nonpredictive assays, and recommended revalidation procedures following changes in assay conditions.

CONCLUSIONS.—

While many of the original guideline statements remain similar, new recommendations address analytic validation of assays with distinct scoring systems, such as programmed death receptor-1 and analytic verification of US Food and Drug Administration approved/cleared assays; more specific guidance is offered for validating immunohistochemistry performed on cytology specimens.

Detection of clinically actionable gene fusions by next-generation sequencing-based RNA sequencing of non-small cell lung cancer cytology specimens: A single-center experience with comparison to fluorescence in situ hybridization

BACKGROUND

Genomic profiling is needed to identify actionable alterations in non-small cell lung cancer (NSCLC). Panel-based testing such as next-generation sequencing (NGS) is often preferred to interrogate multiple alterations simultaneously. In this study, we evaluate the utility of an RNA-based NGS assay to detect genomic alterations in NSCLC cytology specimens and compare these results to fluorescence in situ hybridization (FISH) testing.

METHODS

A retrospective review was performed of 264 NSCLC cytology specimens that were concurrently tested for gene fusions by RNA-based NGS and ALK, RET, and/or ROS1 by FISH.

RESULTS

Genomic alterations were detected in 29 cases by NGS, including ALK, RET, ROS1, NTRK, NUTM1, and FGFR3 fusions and MET exon 14 skipping alterations. Of the 20 cases with ALK, RET, and ROS1 fusions detected by NGS, 16 (80%) were concordant with the corresponding FISH results. Three cases showed discordance, where EML4::ALK (n = 2) and SLC34A2::ROS1 (n = 1) fusions were not detected by the corresponding FISH assay; one case with EZR::ROS1 was inadequate for FISH. No gene fusions were detected in 181 cases by NGS and 54 cases failed testing. The concordance rates for detecting ALK, RET, and ROS1 fusions using NGS and FISH were 97%, 100%, and 99.5%, respectively.

CONCLUSION

RNA-based NGS can be used to detect gene fusions in NSCLC cytology cases with high concordance with FISH results. However, RNA-based NGS may have high failure rates and therefore a low threshold for reflexing inadequate cases to an orthogonal testing method is essential for comprehensive genomic profiling.

Improving the turnaround time of molecular profiling for advanced non-small cell lung cancer: Outcome of a new algorithm integrating multiple approaches

BACKGROUND

Molecular tumor profiling to identify oncogenic drivers and actionable mutations has a profound impact on how lung cancer is treated. Especially in the subgroup of non-small cell lung cancer (NSCLC), molecular testing for certain mutations is crucial in daily clinical practice and is recommended by international guidelines. To date, a standardized approach to identify druggable genetic alterations are lacking. We have developed and implemented a new diagnostic algorithm to harmonize the molecular testing of NSCLC.

PATIENTS AND METHODS

In this retrospective analysis, we reviewed 119 patients diagnosed with NSCLC at the University Hospital Zurich. Tumor samples were analyzed using our standardized diagnostic algorithm: After the histological diagnosis was made, tissue samples were further analyzed by immunohistochemical stainings as well as the real-time PCR test Idylla™. Extracted DNA was further utilized for comprehensive genomic profiling (FoundationOne®CDx, F1CDx).

RESULTS

Out of the 119 patients were included in this study, 100 patients were diagnosed with non-squamous NSCLC (nsqNSCLC) and 19 with squamous NSCLC (sqNSCLC). The samples from the nsqNSCLC patients underwent testing by Idylla™ and were evaluated by immunohistochemistry (IHC). F1CDx analysis was run on 67 samples and 46 potentially actionable genomic alterations were detected. Ten patients received the indicated targeted treatment. The median time to test results was 4 days for the Idylla test, 5 days for IHC and 13 days for the F1CDx.

CONCLUSION

In patients with NSCLC, the implementation of a standardized molecular testing algorithm provided information on predictive markers for NSCLC within a few working days. The implementation of broader genomic profiling led to the identification of actionable targets, which would otherwise not have been discovered.

Overview and update on molecular testing in non-small cell lung carcinoma utilizing endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples

Lung carcinoma remains one of the most frequent and aggressive human neoplasms. Fortunately, in the last decades, the increasing knowledge of the molecular mechanisms leading to cancer development has allowed the use of targeted therapies with improvement of prognosis in many patients. Clinical management has also changed after the introduction of endobronchialultrasonographic bronchoscopy that allows a conservative staging of lung tumors, avoiding the need of mediastinoscopy for lymph node staging. Lung pathologists and cytopathologists are facing the challenge of giving the more comprehensive prognostic and predictive information with ever smaller tissue or cytological samples. The aim of this review is to summarize the molecular testing for non-small cell lung carcinoma and how pathologists can contribute to the patient's outcome with a conscious management of biological samples.

Prädiktive Immunzytochemie beim nicht-kleinzelligen Lungenkarzinom

Die Immunchemie ist eine zeit-, tumorproben- und kosteneffiziente Methode zur Untersuchung prädiktiver Biomarker bei fortgeschrittenen nicht-kleinzelligen Lungenkarzinomen (NSCLC). Die Immunhistochemie (IHC) an Formalin-fixiertem, Paraffin-eingebettetem (FFPE) Tumorgewebe hat sich für den Nachweis der PD-L1-Expression sowie für die ALK-, ROS1- und neuerdings auch für die NTRK-Untersuchung bewährt. Zytologische Proben als Quelle für prädiktive Markeranalysen sind sehr wichtig, da bis zu 40 % aller NSCLC rein zytologisch diagnostiziert werden.

Trotz der etablierten Rolle der Zytologie in der Lungenkarzinomdiagnostik wurden keine kommerziellen IHC-Assays für zytologische Proben validiert.

Die prädiktive Immunzytochemie (ICC) ist am einfachsten an FFPE-Zellblöcken (CB) durchzuführen, da für FFPE-Histologie standardisierte Protokolle verwendet werden können. CB sind jedoch nicht immer verfügbar.

Nicht als CB verarbeitete zytologische Präparate sind weniger standardisiert als histologische Präparate und weisen eine erhebliche präanalytische Variabilität auf. Daher ist eine strenge zytologiespezifische Optimierung, Validierung und Qualitätskontrolle von ICC-Protokollen erforderlich. Unter dieser Voraussetzung ist die prädiktive ICC, die in der Regel an Papanicolaou-gefärbten Zytologien durchgeführt wird, robust und zuverlässig. Dieses wertvolle zytologische Material sollte für prädiktive Biomarkeranalysen genutzt werden, um Patientinnen und Patienten nicht dem unnötigen Risiko einer erneuten Probenentnahme auszusetzen. Diese Übersichtsarbeit beleuchtet präanalytische, analytische und postanalytische Aspekte, die ICC-Ergebnisse beeinflussen können, und fasst die veröffentlichten Daten zur prädiktiven ICC für PD-L1, ALK und ROS1 bei NSCLC zusammen.

Molecular Testing on Cytology for Gene Fusion Detection

Cytology samples are suitable for the study of genotypic and phenotypic changes observed in different tumors. Being a minimally invasive technique, cytology sampling has been used as an acceptable alternative to track the alterations associated with tumor progression. Although the detection of gene mutations is well-established on cytology, in the last few years, gene fusion detections are becoming mandatory, especially in some tumor types such as lung cancer. Different technologies are available such as immunocytochemistry, fluorescence in situ hybridization, reverse transcription-polymerase chain reaction, and massive parallel sequencing approaches. Considering that many new drugs targeted fusion proteins, cytological samples can be of use to detect gene fusions in solid and lymphoproliferative tumor patients. In this article, we revised the use of several techniques utilized to check gene fusions in cytological material.

Immunocytochemical Detection of ALK and ROS1 Rearrangements in Lung Cancer Cytological Samples

The detection of molecular alterations such as ROS1 and ALK rearrangements is performed as part of the diagnosis of advanced-stage lung adenocarcinoma. These alterations allow the treatments with tyrosine kinase inhibitors. Cytological samples are very useful as up to 40% patients are diagnosed with this type of sample. Here we describe the immunocytochemistry technique usable to reveal the overexpression of ALK or ROS1 tyrosine kinase receptors secondary to ALK and ROS1 rearrangements, respectively.

Challenges of ICC and FISH in the Field of Targeted Therapies from Cell Block to Smears

In the era of personalized medicine, there is an increasing demand for comprehensive and complex diagnosis using minimally invasive techniques. Nowadays, it is mandatory to integrate biomarkers in the diagnostic process, as well as in the treatment and clinical management of many cancer patients. Patients with non-small cell lung cancer (NSCLC), for instance, are frequently diagnosed in advanced stages, at a point when only cytological material or small biopsies can be obtained. This pathology constitutes an interesting challenge for the testing of biomarkers in cytology. Furthermore, there is a growing development of imaging techniques that guide non-invasive approaches to obtain small biopsies or cytological samples. This has allowed fine needle aspiration cytology and fine needle aspiration biopsy (FNAC, FNAB) to become front-line procedures in the management of patients with NSCLC. It is well known that the list of biomarkers to be tested in these patients continues to increase. Nevertheless, there are several of essential biomarkers that should always be analyzed in all patients with NSCLC, not only in non-squamous but also in some squamous carcinomas (SqCC). Some of them, such as PDL1, are tested by immunocytochemistry (ICC), while others, mainly ALK and ROS1, can be tested by ICC and confirmed using other techniques such a Fluorescence In Situ Hybridization (FISH). Other biomarkers, namely EGFR and BRAF mutations, are currently evaluated by polymerase chain reaction (PCR)-based techniques including Next-Generation Sequencing (NGS). In this review, we will address the particularities and challenges that ICC and FISH pose in different types of cytological samples from an eminently practical point of view.

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.

Comparison of Next-Generation Sequencing and Ventana Immunohistochemistry in Detecting ALK Rearrangements and Predicting the Efficacy of First-Line Crizotinib in Patients with Advanced Non-Small Cell Lung Cancer

Introduction

Reliable diagnostic approaches to detect ALK rearrangement are critical for selecting patients eligible for crizotinib therapy. This study aimed to compare next-generation sequencing (NGS) and Ventana immunohistochemistry (IHC) in evaluating ALK rearrangements and evaluate their impact on first-line crizotinib efficacy.

Patients and Methods

A total of 472 NSCLC patients were identified as ALK-positive by NGS and/or IHC between March 2014 and February 2020. The concordance of ALK detection, overall response rate (ORR), and progression-free survival (PFS) were analyzed for 319 patients who received front-line crizotinib.

Results

First-line crizotinib (n=319) significantly prolonged PFS in comparison with chemotherapy (n=46; 12.0 vs 6.8 months; p<0.0001). Of the 76 crizotinib-treated patients whose ALK status was assessed by both NGS and IHC, 78.9% of the patients had concordant ALK status (NGS-positive/IHC-positive), 18.4% patients were NGS-positive but IHC-negative, and 2 patients were IHC-positive but NGS-negative. Different detection assays confer no statistical difference in ORR and PFS with first-line crizotinib. The ORR in NGS only, IHC only, and both NGS and IHC was 84.3%, 90.1%, and 88.1%, respectively, while PFS was 11.4, 13.0, and 11.0 months, respectively. The ORR in NGS-positive/IHC-positive and NGS-positive/IHC-negative patients was 85.4% and 92.8%, respectively. Compared to NGS-positive/IHC-positive patients, those with NGS-positive/IHC-negative results had a trend of shorter PFS but statistical significance was not reached (mPFS, 5.9 months vs 11.5 months, p=0.43).

Conclusion

Our results demonstrate that ALK status detected by NGS and/or IHC is reliable in identifying patients with ALK-positive NSCLC who will benefit from ALK inhibitor therapy.

Immunocytochemistry of cytology specimens for predictive biomarkers in lung cancer

With a growing number of predictive biomarkers that have emerged in non-small cell lung carcinoma (NSCLC), there has been a paradigm shift in the management of these patients. Of the various predictive biomarker testing methods, immunohistochemistry (IHC) is the most widely available, cost-effective, and commonly used methods. However, most predictive IHC assays are validated primarily on formalin-fixed paraffin-embedded (FFPE) histologic tissue samples and translating these assays to cytologic specimens requires additional and rigorous validation. This is part due to the lack of standardized processing protocols in cytology resulting in a variety of preanalytic variables that can impact the antigenicity of antibodies used for predictive biomarker testing. The review article discusses the various preanalytical and analytical factors that impact immunocytochemistry (ICC) in cytologic specimens and summarizes the current published literature on ALK, ROS1, PD-L1, and other predictive biomarker ICC in cytology.

ALK and ROS1 rearrangement tested by ARMS-PCR in non-small-cell lung cancer patients via cytology specimens: The experience of Shanghai Pulmonary Hospital

BACKGROUND

Cytology specimens are the main samples used for the diagnosis of advanced lung cancer. The objective of our study was to assess anaplastic lymphoma kinase (ALK) and c-ros oncogene 1 receptor tyrosine kinase (ROS1) genes by an amplification refractory mutation system (ARMS)-polymerase chain reaction (PCR) using cytology specimens and to then evaluate the mutation frequency of ALK and ROS1 in non-small-cell lung cancer (NSCLC) patients.

METHODS

A large cohort that consisted of 8180 NSCLC patients who were genetically tested using cytology samples or formalin-fixed and paraffin-embedded (FFPE) samples (tumor tissue or biopsy) from January 2015 to December 2018 were screened. The gene rearrangement ratio and clinical characteristics of the two sample groups were analyzed by SPSS software.

RESULTS

In our hospital, cytology specimens are the main resource used for gene testing in NSCLC. In most cases, an abundant quantity of nucleic acid was extracted from the residual liquid-based cell pellet for testing the ALK and ROS1 genes. In certain cases, when the residual cell pellet was insufficient for the gene testing, the cell block and liquid-based cell smear served as alternative options. In addition, we retrospectively analyzed our previous data, and the mutation ratio of the ALK/ROS1 rearrangements obtained by using the cytology samples (4.98%/1.80%) and the FFPE samples (6.06%/1.62%) was almost the same (P-value = .09/.634).

CONCLUSIONS

This study demonstrated that AMRS-PCR method can effectively identify ALK and ROS1 gene rearrangements and cytology specimens might be an excellent source for routine molecular testing in patients with advanced NSCLC.

Treatment of anaplastic lymphoma kinase-positive non-small cell lung cancer: update and perspectives

PURPOSE OF REVIEW

We describe recent developments in the rapidly evolving field of anaplastic lymphoma kinase-targeting agents.

RECENT FINDINGS

Five targeted drugs are currently available in the clinic via regular approval or named patient programs, including crizotinib, ceritinib, alectinib, brigatinib and lorlatinib. Further drugs are tested in clinical trials. This review summarizes published data, together with drug-specific information on dosing and toxicity. Moreover, we discuss different clinical scenarios and potential treatment options in patients with tumor progression, based on current literature and our own experience.

SUMMARY

Patients with metastatic, anaplastic lymphoma kinase-rearranged nonsmall cell lung cancer should be managed by interdisciplinary expert teams. New drugs with enhanced brain activity are available, and some patients may benefit from local therapies.

Guidelines for diagnostic flexible bronchoscopy in adults: Joint Indian Chest Society/National College of chest physicians (I)/Indian association for bronchology recommendations

Flexible bronchoscopy (FB) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. However, bronchoscopy practices vary widely across India and worldwide. The three major respiratory organizations of the country supported a national-level expert group that formulated a comprehensive guideline document for FB based on a detailed appraisal of available evidence. These guidelines are an attempt to provide the bronchoscopist with the most scientifically sound as well as practical approach of bronchoscopy. It involved framing appropriate questions, review and critical appraisal of the relevant literature and reaching a recommendation by the expert groups. The guidelines cover major areas in basic bronchoscopy including (but not limited to), indications for procedure, patient preparation, various sampling procedures, bronchoscopy in the ICU setting, equipment care, and training issues. The target audience is respiratory physicians working in India and well as other parts of the world. It is hoped that this document would serve as a complete reference guide for all pulmonary physicians performing or desiring to learn the technique of flexible bronchoscopy.

Immunocytochemistry for predictive biomarker testing in lung cancer cytology

With an escalating number of predictive biomarkers emerging in non-small cell lung carcinoma (NSCLC), immunohistochemistry (IHC) is being used as a rapid and cost-effective tool for the screening and detection of many of these markers. In particular, robust IHC assays performed on formalin-fixed, paraffin-embedded (FFPE) tumor tissue are widely used as surrogate markers for ALK and ROS1 rearrangements and for detecting programmed death ligand 1 (PD-L1) expression in patients with advanced NSCLC; in addition, they have become essential for treatment decisions. Cytology samples represent the only source of tumor in a significant proportion of patients with inoperable NSCLC, and there is increasing demand for predictive biomarker testing on them. However, the wide variation in the types of cytology samples and their preparatory methods, the use of alcohol-based fixatives that interfere with immunochemistry results, the difficulty in procurement of cytology-specific controls, and the uncertainty regarding test validity have resulted in underutilization of cytology material for predictive immunocytochemistry (ICC), and most cytopathologists limit such testing to FFPE cell blocks (CBs). The purpose of this review is to: 1) analyze various preanalytical, analytical, and postanalytical factors influencing ICC results; 2) discuss measures for validation of ICC protocols; and 3) summarize published data on predictive ICC for ALK, ROS1, EGFR gene alterations and PD-L1 expression on lung cancer cytology. Based on our experience and from a review of the literature, we conclude that cytology specimens are in principal suitable for predictive ICC, but proper optimization and rigorous quality control for high-quality staining are essential, particularly for non-CB preparations.

The Role of Ancillary Techniques in Pulmonary Cytopathology

Ancillary techniques play an essential role in pulmonary cytopathology. Immunoperoxidase and special stains are by far the most common ancillary techniques used in cytopathology; however, the role of molecular diagnosis is growing, especially in the fields of pulmonary oncology and infectious disease. In this article, we review the uses of ancillary techniques in lung tumor diagnosis, lung tumor classification, predictive marker determination, primary versus metastasis differential diagnosis, and infectious organism detection.

Lung Molecular Cytopathology: EGFR and Beyond

Lung cancer (LC) is the leading cause of cancer-related mortality. Unfortunately, most patients of LC present at the advanced stage of the disease with a poor prognosis and 1-year survival of less than 20%. At the advanced stage of the disease, surgical resection cannot be possible, hence small biopsy or cytology specimens remain a choice for their correct diagnosis. The recognition of molecular drivers has revolutionized the treatment paradigm of non-small cell lung cancer (NSCLC) with introduction of tyrosine kinase inhibitors. Epidermal growth factor receptor (EGFR) gene mutations were identified, first, to be targeted in NSCLC followed by activating fusions in anaplastic lymphoma kinase (ALK) and rearrangements in c-ros oncogene 1 (ROS1) genes. In addition, the encouraging progress of immunotherapy in patients with NSCLC has been associated with predictive biomarker testing in the form of programmed death ligand-1 (PD-L1) immunohistochemistry assay. To test for these alterations, accurate biomarker testing is needed from biopsy or cytology specimens. In this brief review, testing of biomarkers is discussed using cytology specimens.

Best Practices Recommendations for Diagnostic Immunohistochemistry in Lung Cancer

Since the 2015 WHO classification was introduced into clinical practice, immunohistochemistry (IHC) has figured prominently in lung cancer diagnosis. In addition to distinction of small cell versus non-small cell carcinoma, patients' treatment of choice is directly linked to histologic subtypes of non-small cell carcinoma, which pertains to IHC results, particularly for poorly differentiated tumors. The use of IHC has improved diagnostic accuracy in the classification of lung carcinoma, but the interpretation of IHC results remains challenging in some instances. Also, pathologists must be aware of many interpretation pitfalls, and the use of IHC should be efficient to spare the tissue for molecular testing. The International Association for the Study of Lung Cancer Pathology Committee received questions on practical application and interpretation of IHC in lung cancer diagnosis. After discussions in several International Association for the Study of Lung Cancer Pathology Committee meetings, the issues and caveats were summarized in terms of 11 key questions covering common and important diagnostic situations in a daily clinical practice with some relevant challenging queries. The questions cover topics such as the best IHC markers for distinguishing NSCLC subtypes, differences in thyroid transcription factor 1 clones, and the utility of IHC in diagnosing uncommon subtypes of lung cancer and distinguishing primary from metastatic tumors. This article provides answers and explanations for the key questions about the use of IHC in diagnosis of lung carcinoma, representing viewpoints of experts in thoracic pathology that should assist the community in the appropriate use of IHC in diagnostic pathology.

To Obtain More With Less: Cytologic Samples With Ancillary Molecular Techniques-The Useful Role of Liquid-Based Cytology

CONTEXT

- Fine-needle aspiration cytology has been increasingly used as the first tool in the evaluation of several diseases. Although cytology has a relevant role in the discrimination between benign and malignant lesions, conventional slides cannot lead to 100% conclusive results. It was hoped that the introduction of liquid-based cytology (LBC) would improve the efficacy of cytology through standardization, quality improvement, and the possibility of carrying out ancillary techniques on the residual stored material. In recent decades, the application of genomic alterations has been studied on cytologic samples with feasible and reliable results. The molecular analysis offers a powerful aid to define the best clinical or surgical approaches and follow-up for patients. In recent years, the application of different ancillary techniques has been carried out on conventional slides even though LBC represents a useful additional and alternative method for molecular testing.

OBJECTIVE

- To demonstrate the relevance of LBC as a valid aid to overcoming the difficulties encountered in the application of ancillary techniques on conventional slides.

DATA SOURCES

- We examined and reviewed our experience with the application of ancillary techniques on LBC performed on different body sites.

CONCLUSIONS

- We emphasize that LBC achieves significant and accurate results. It represents a valid method for cytologic evaluation and it provides highly reproducible and informative molecular yields.

The utilization of cytologic and small biopsy samples for ancillary molecular testing

There has recently been an increased emphasis on the utilization of cytologic samples and small biopsies for not only diagnostic purposes but also for ancillary testing. In some instances, the ancillary tests contribute to the diagnosis and in other scenarios, they provide prognostic and theranostic information for the management of patients with advanced stage cancer. These ancillary tests include immunohistochemical biomarker analysis, molecular mutation analysis, and cytogenetic tests. Despite the finite nature of the cellular material procured in cytologic and small tissue biopsies, pathologists are tasked with ordering an increasing number of tests using these limited samples. This requires the pathologists to utilize and triage these samples in an optimal fashion so that as much information can be gleaned from a given specimen. This review will focus on the pre-analytic requirements for ancillary molecular and cytogenetic tests in the context of a discussion of the various preparation methods for cytologic and small biopsy specimens. The goal will be to provide the reader with the necessary concepts that can be utilized to develop optimal specimen selection and triage strategies to maximize the chances of effectively utilizing these samples for comprehensive diagnostic and relevant ancillary testing purposes.

Application of Ventana immunocytochemical analysis on ThinPrep cytology slides for detection of ALK rearrangement in patients with advanced non-small-cell lung cancer

Background

Ventana ALK (D5F3) screening of anaplastic lymphoma kinase (ALK) gene rearrangement in tissue specimens has been approved by US FDA (Food and Drug Administration) to select treatment for non–small-cell lung carcinoma (NSCLC). However, tumor tissues are often not readily obtainable, and cytology specimens and may be the only tumor material available for diagnosis and molecular marker analysis. In this study, we evaluated the feasibility of ALK immunocytochemistry (ICC) on ThinPrep slides and determined a suitable scoring system for interpretation of the results.

Methods

One hundred twenty-one fine-needle aspirate (FNA) specimens from metastatic lesions of NSCLC were analyzed. ALK rearrangement was detected on ThinPrep cytology slides using the Ventana immunocytochemistry ALK-D5F3 system, which adopts two scoring systems for interpretation of the ICC results. The results were subsequently confirmed by reverse transcription polymerase chain reaction (RT-PCR) analysis and fluorescence in situ hybridization (FISH).

Results

Among the 121 ICC specimens, 16 that were considered ALK-positive by either scoring system were referred for PCR analysis. Among the ALK ICC-negative cases, 33 had correlated FISH ALK results. A total of 49 specimens that exhibited either a positive or negative ICC result with a correlated ALK status were analyzed statistically. ICC results showed a high concordance rate with the results of PCR/FISH analysis. The sensitivity and specificity of ALK ICC by the binary scoring algorithm were 68.75 and 96.97%, respectively. These values increased to 93.75 and 96.97%, respectively, when interpreted by the semiquantified interpretation system.

Conclusions

ALK ICC analysis on ThinPrep slides is a reliable ALK testing method, and the semiquantified interpretation system on cytology specimens is recommended rather than the binary scoring algorithm on tissue specimens.

Qualitative and quantitative cytomorphological features of primary anaplastic lymphoma kinase-positive lung cancer

OBJECTIVE

Anaplastic lymphoma kinase (ALK) positive (+) lung cancers are predictive for response to crizotinib and alectinib. There are many cases of lung cancer in which surgery cannot be performed, and such cases require diagnosis by cytological specimen or biopsy. Estimating ALK (+) lung cancer from cytomorphology would allow molecular testing to proceed without the waste of a small amount of specimen. The purpose of this study was to assess whether qualitative and quantitative cytomorphological features are sufficient for distinguishing primary ALK (+) from ALK (-) lung cancer.

METHODS

We examined eight qualitative cytomorphological parameters and three quantitative nuclear morphometric parameters in 17 cases of primary ALK (+) lung cancer, diagnosed by fluorescence in situ hybridisation (FISH) using histological specimens, and in 41 cases of ALK (-) lung cancer. Quantitative nuclear morphometric parameters were analysed by a computer-assisted image analysis system.

RESULTS

In ALK (+) lung cancer, three qualitative parameters (signet ring cells, nuclear grooves and single type nucleoli) and two quantitative parameters (large nuclear area and irregular nuclear shape) were observed in significantly higher proportions. However, in ALK (-) lung cancer, one qualitative parameter (unclear and multiple type nucleoli) was seen significantly more often.

CONCLUSIONS

These results show that the cytomorphological features of signet ring cells, nuclear grooves and nucleoli shape can help to triage a small amount of cytological and biopsy specimens for appropriate molecular testing of primary ALK (+) lung cancer.

Discordance between FISH, IHC, and NGS Analysis of ALK Status in Advanced Non-Small Cell Lung Cancer (NSCLC): a Brief Report of 7 Cases

BACKGROUND: Anaplastic lymphoma kinase (ALK) rearrangement represents a landmark in the targeted therapy of non–small cell lung cancer (NSCLC). Immunohistochemistry (IHC) is a sensitive and specific method to detect ALK protein expression, possibly an alternative to fluorescence in situ hybridization (FISH). In this study, the concordance of FISH and IHC to determine ALK status was evaluated, particularly focusing on discordant cases. MATERIALS AND METHODS: ALK status was tested by FISH and the IHC validated method (Ventana ALK (D5F3) CDx Assay) in 95 NSCLCs. Discordant cases were analyzed also by next-generation sequencing (NGS). The response to crizotinib of treated patients was recorded. RESULTS: Seven (7.3%) discordant cases were ALK FISH positive and IHC negative. They showed coexistent split signals pattern, with mean percentage of 15.4%, and 5′ deletions pattern, with mean percentage 31.7%. Two cases had also gene amplification pattern. In three cases (42.8 %), the polysomy was observed. The NGS assay confirmed IHC results. In these patients, the treatment with crizotinib was ineffective. CONCLUSIONS: In our discordant cases, a coexistent complex pattern (deleted, split, and amplified/polysomic) of ALK gene was observed by FISH analysis. These complex rearranged cases were not detectable by IHC, and it could be speculated that more complex biological mechanisms could modulate protein expression. These data highlight the role of IHC and underscore the complexity of the genetic pattern of ALK. It could be crucial to consider these findings in order to best select patients for anti-ALK treatment in daily clinical practice.

Globo H expression is associated with driver mutations and PD-L1 expressions in stage I non-small cell lung cancer

BACKGROUND

Globo H is a tumor-associated carbohydrate antigen exclusively expressed in cancer cells rather than normal tissue. Globo H has been found on many cancers of epithelial origins, and become an attractive target for cancer vaccine.

OBJECTIVES

We aimed to study the expression of Globo H in non-small cell lung cancer (NSCLC) patients, and correlated its expression with common driver mutations, clinical outcomes, and status of immune checkpoint, programmed death-ligand 1 (PD-L1).

METHODS

The study enrolled 228 patients with surgically resected stage I NSCLC, including 139 patients with adenocarcinoma (ADC) and 89 patients with squamous cell carcinoma (SqCC). Using immunohistochemistry, tumors with moderate to strong membranous staining in ⩾ 1% tumor cells per section were scored as positive Globo H expression. Driver mutations including EGFR, KRAS, BRAF were detected by direct sequencing, while ALK, PI3KCA, FGFR1 and PD-L1 expression was detected by immunohistochemical (IHC) staining.

RESULTS

Positive Globo H expression was detected in 88 of the 228 (38.6%) patients. These included 51 of 139 (36.7%) patients with ADC and 37 of 89 (41.6%) patients with SqCC. Positive Globo H expression was significantly associated with EGFR mutation and PD-L1 expression in the ADC group, and PI3KCA overexpression in the SqCC group. The survival analysis showed that Globo H expression was not an independent prognostic factor in stage I NSCLC.

CONCLUSIONS

Globo H expression was correlated with specific driver mutations in ADC and SqCC NSCLC tumors, as well as PD-L1 status. Immunotherapy targeting Globo H may have potential application in lung cancer treatment.

Tru-cut/core Biopsy versus FNAC: Pulmonary Tumors

Primary lung epithelial malignancies are the most common neoplasms among all pulmonary tumors. Lung cancer (LC) is the leading cause of cancer-related mortality for which a histologic or cytologic confirmation of malignancy is required before treatment. Specimen management is an important task for pathologists in the field of LC. Biopsy and fine needle aspiration are comparable. It is desirable to have both for diagnosis and mutation testing to maximize their use for patient care.

Anaplastic lymphoma kinase immunohistochemistry in lung adenocarcinomas: Evaluation of performance of standard manual method using D5F3 antibody

OBJECTIVE

Immunohistochemistry (IHC) with anaplastic lymphoma kinase (ALK) antibodies is considered as an economical screening method in lung adenocarcinomas. Automated Ventana D5F3-IHC is approved by US Food and Drug Administration for targeted therapy; however, the automated IHC apparatus are not widely used in most laboratories. We evaluated the performance of ALK IHC using the manual semiquantitative method to assess the concordance with Ventana ALK IHC assay.

MATERIALS AND METHODS

We tested 156 cases of primary lung adenocarcinomas for ALK protein expression by D5F3-IHC. The intensity of cytoplasmic staining was classified as 0 or 1+/2+/3+ (weak/medium/strong). Binary score of positive and negative was used for Ventana assay. A comparison analysis and clinicopathological features were recorded.

RESULTS

ALK IHC was positive in 25 (16.02%) cases, of which 18 were men and mostly nonsmokers. The mean age for all patients was 55 years, and for ALK IHC-positive cases was 48 years. Nine of 25 (36%) ALK IHC-positive cases showed signet ring cell and mucinous morphology. On comparison, all, but one, cases positive by manual method showed positive results by automated assay. IHC negative cases by manual method were negative by Ventana assay.

CONCLUSION

Manual IHC is equally effective in the detection of ALK-rearranged cases as automated methods. It can be easily integrated as a screening method into routine practice thus reducing the cost of automated systems. However, equivocal cases should be tested by approved methods.

Simultaneous VENTANA IHC and RT-PCR testing of ALK status in Chinese non-small cell lung cancer patients and response to crizotinib

Background

ALK rearrangement-advanced NSCLC patients respond to crizotinib. ALK rearrangement is currently determined with RT-PCR. VENTANA IHC is a standard method to identify ALK protein overexpression in NSCLC; however, VENTANA IHC has rarely been used to determine the response to crizotinib in Chinese patients with NSCLC and ALK overexpression. To better clarify the clinical implication of VENTANA IHC to detect ALK rearrangements, we conducted this study to analyze VENTANA IHC and RT-PCR in a large cohort of Chinese patients with NSCLC undergoing screening for ALK rearrangements.

Methods

A total of 1720 patients with NSCLC who had ALK rearrangements detected by VENTANA IHC and/or RT-PCR were included in this analysis. We compared the efficacy and survival of ALK-positive patients detected by VENTANA IHC and RT-PCR. We used NGS to identify patients in whom the two methods were inconsistent.

Results

Among 1720 patients, 187 (10.87%) were shown to be ALK-positive by VENTANA IHC and/or RT-PCR, and 66 received crizotinib treatment. We identified 10.27% (172/1674) of patients as ALK-positive by the VENTANA IHC method, and 12.73% (41/322) of patients had ALK rearrangements by the RT-PCR method. Twenty-nine of 276 (10.51%) ALK-positive patients were simultaneously analyzed using VENTANA IHC and RT-PCR. The overall response rates were 65.90% (29/44) by VENTANA IHC and 55.88% (19/34) by RT-PCR. The disease control rates were 86.36% (38/44) by VENTANA IHC and 76.47% (26/34) by RT-PCR. In contrast, the median progression-free survival for VENTANA IHC and RT-PCR was 8.5 and 9.2 months, respectively. The VENTANA IHC and RT-PCR results obtained for 6 of 17 ALK-positive patients were inconsistent based on NGS; specifically, 4 patients had EML4-ALK fusions, 2 patients had non EML4-ALK fusions, 1 patient had a KCL1-ALK fusion, and one patient had a FBXO36-ALK fusion.

Conclusions

VENTANA IHC is a reliable and rapid screening tool used in routine pathologic laboratories for the identification of suitable candidates for ALK-targeted therapy. VENTANA IHC has moderate sensitivity and a slightly higher association with response to therapy with ALK inhibitors, and some VENTANA IHC-positive, but RT-PCR-negative cases may benefit from crizotinib.

NSCLC molecular testing in Central and Eastern European countries

Background

The introduction of targeted treatments for subsets of non-small cell lung cancer (NSCLC) has highlighted the importance of accurate molecular diagnosis to determine if an actionable genetic alteration is present. Few data are available for Central and Eastern Europe (CEE) on mutation rates, testing rates, and compliance with testing guidelines.

Methods

A questionnaire about molecular testing and NSCLC management was distributed to relevant specialists in nine CEE countries, and pathologists were asked to provide the results of EGFR and ALK testing over a 1-year period.

Results

A very high proportion of lung cancer cases are confirmed histologically/cytologically (75–100%), and molecular testing of NSCLC samples has been established in all evaluated CEE countries in 2014. Most countries follow national or international guidelines on which patients to test for EGFR mutations and ALK rearrangements. In most centers at that time, testing was undertaken on request of the clinician rather than on the preferred reflex basis. Immunohistochemistry, followed by fluorescent in situ hybridization confirmation of positive cases, has been widely adopted for ALK testing in the region. Limited reimbursement is a significant barrier to molecular testing in the region and a disincentive to reflex testing. Multidisciplinary tumor boards are established in most of the countries and centers, with 75–100% of cases being discussed at a multidisciplinary tumor board at specialized centers.

Conclusions

Molecular testing is established throughout the CEE region, but improved and unbiased reimbursement remains a major challenge for the future. Increasing the number of patients reviewed by multidisciplinary boards outside of major centers and access to targeted therapy based on the result of molecular testing are other major challenges.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4023-4) contains supplementary material, which is available to authorized users.

Molecular Testing of Non-Small Cell Lung Carcinoma Diagnosed by Endobronchial Ultrasound-Guided Transbronchial Fine-Needle Aspiration: The Cleveland Clinic Experience

CONTEXT.—

Given the increasing demand for molecular testing of non-small cell lung carcinoma specimens to guide therapeutic decision-making and the trend toward minimally invasive techniques for obtaining diagnostic tissue, cytopathology laboratories must devise strategies to maximize DNA yield for necessary molecular testing.

OBJECTIVE.—

To describe our experience at Cleveland Clinic with epidermal growth factor receptor (EGFR) mutation testing by next-generation sequencing and anaplastic lymphoma kinase (ALK) gene rearrangement testing by fluorescence in situ hybridization of non-small cell lung carcinomas diagnosed by cytology, with an emphasis on specimens obtained by endobronchial ultrasound-guided transbronchial fine-needle aspiration.

DATA SOURCES.—

Data sources include a review of the current literature, including published articles from our institution.

CONCLUSIONS.—

At our institution, liquid-based cytology specimens are the primary resource used for molecular testing of non-small cell lung carcinomas; in most instances, adequate DNA can be extracted from the residual cell pellet for next-generation sequencing, and ThinPrep slides can be used reliably for fluorescence in situ hybridization testing for ALK gene rearrangements. In occasional cases where the cell pellet material is not adequate for molecular testing, cell blocks and/or surgical pathology specimens are secondary options. The cytopathologist's role in specimen handling and triage is essential to ensure that molecular testing can be carried out successfully.

Lung cancer as a paradigm for precision oncology in solid tumours

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death in the western world. However, the combination of molecular genotyping and subsequent systematic treatment of decoded target structures is a prime example of precision oncology in solid tumours. In this review, current targets of approved therapeutics and potential targets in clinical and preclinical trials are outlined. Furthermore, immune checkpoint inhibitors, as promising new therapeutic options, which have already been applied successfully in cases of lung cancer, are introduced. A major issue of targeted treatment of lung tumours is the persistent development of resistance. The underlying mechanisms and established and potentially applicable alternative therapeutic approaches are described. In this process of precision oncology, immunohistochemistry, fluorescence in situ hybridization, and parallel sequencing are crucial diagnostic tools.

Immunohistochemistry of Pulmonary Biomarkers: A Perspective From Members of the Pulmonary Pathology Society

The use of immunohistochemistry for the determination of pulmonary carcinoma biomarkers is a well-established and powerful technique. Immunohistochemisty is readily available in pathology laboratories, is relatively easy to perform and assess, can provide clinically meaningful results very quickly, and is relatively inexpensive. Pulmonary predictive biomarkers provide results essential for timely and accurate therapeutic decision making; for patients with metastatic non-small cell lung cancer, predictive immunohistochemistry includes ALK and programmed death ligand-1 (PD-L1) (ROS1, EGFR in Europe) testing. Handling along proper methodologic lines is needed to ensure patients receive the most accurate and representative test outcomes.

Nonsmall cell lung carcinoma: diagnostic difficulties in small biopsies and cytological specimens

The pathological and molecular classification of lung cancer has become substantially more complex over the past decade. For diagnostic purposes on small samples, additional stains are frequently required to distinguish between squamous cell carcinoma and adenocarcinoma. Subsequently, for advanced nonsquamous cell nonsmall cell lung carcinoma (NSCLC) patients, predictive analyses on epidermal growth factor receptor, anaplastic lymphoma kinase and ROS1 are required. In NSCLCs negative for these biomarkers, programmed death ligand-1 immunohistochemistry is performed. Small samples (biopsy and cytology) require “tissue” management, which is best achieved by the interaction of all physicians involved.

Diagnosis of anaplastic lymphoma kinase rearrangement in cytological samples through a fluorescence in situ hybridization-based assay: Cytological smears versus cell blocks

Anaplastic lymphoma kinase (ALK) status analysis of lung cytological specimens should be successfully encouraged in routine practice because biopsy specimens are not always available. To date, the US Food and Drug Administration has approved both fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) as diagnostic tests for identifying ALK-positive patients eligible for treatment with crizotinib. Although ALK IHC is an optimal diagnostic tool, FISH becomes mandatory in equivocal cases. ALK FISH of paraffin-embedded tissue material is still the gold standard, whereas the cytological specimen assay has not yet been completely standardized. Many controversial data have been reported on the adequacy of cytology cell blocks (CBs) versus conventional smears for FISH testing. This review discusses some critical issues related to ALK FISH of cytological samples, including the triaging of collected specimens to optimize the material, the use of CBs versus conventional smears, and alternative methods for an ALK rearrangement diagnosis. Conventional smears have the advantages of an immediate evaluation, no probe tissue-related artifactual loss, no fixation-related alterations, and usually sufficient material for an analytic preparation. On the other hand, CBs have several advantages, including the appropriate conservation of the tissue architecture, an absence of problems related to cell overlapping, and the ability to evaluate neoplastic cells in a dark field. Cancer Cytopathol 2017;125:303-312. © 2017 American Cancer Society.

Lung Carcinoma Predictive Biomarker Testing by Immunoperoxidase Stains in Cytology and Small Biopsy Specimens: Advantages and Limitations

CONTEXT

- In the burgeoning era of molecular genomics, immunoperoxidase (IPOX) testing grows increasingly relevant as an efficient and effective molecular screening tool. Patients with lung carcinoma may especially benefit from the use of IPOX because most lung carcinomas are inoperable at diagnosis and only diagnosed by small tissue biopsy or fine-needle sampling. When such small specimens are at times inadequate for molecular testing, positive IPOX results still provide actionable information.

OBJECTIVE

- To describe the benefits and pitfalls of IPOX in the detection of biomarkers in lung carcinoma cytology specimens and small biopsies by summarizing the currently available commercial antibodies, preanalytic variables, and analytic considerations.

DATA SOURCES

- PubMed.

CONCLUSIONS

- Commercial antibodies exist for IPOX detection of aberrant protein expression due to EGFR L858R mutation, EGFR E746_A750 deletion, ALK rearrangement, ROS1 rearrangement, and BRAF V600E mutation, as well as PD-L1 expression in tumor cells. Automated IPOX protocols for ALK and PD-L1 detection were recently approved by the Food and Drug Administration as companion diagnostics for targeted therapies, but consistent interpretive criteria remain to be elucidated, and such protocols do not yet exist for other biomarkers. The inclusion of cytology specimens in clinical trials would expand patients' access to testing and treatment, yet there is a scarcity of clinical trial data regarding the application of IPOX to cytology, which can be attributed to trial designers' lack of familiarity with the advantages and limitations of cytology. The content of this review may be used to inform clinical trial design and advance IPOX validation studies.

Improving Selection Criteria for ALK Inhibitor Therapy in Non-Small Cell Lung Cancer: A Pooled-Data Analysis on Diagnostic Operating Characteristics of Immunohistochemistry

Lung cancer is often diagnosed by molecular markers for prediction and treatment. To date, the golden standard for detection of anaplastic lymphoma kinase (ALK) rearrangements is fluorescence in situ hybridization (FISH). We performed a pooled-data analysis on the diagnostic operating characteristics of immunohistochemistry (IHC) assay on non-small cell lung cancer (NSCLC). We searched Embase, Pubmed, and Springer databases. The results of IHC were evaluated using a modified H-score. We used a 2-level bivariate meta-analysis following a random effect model to summarize sensitivity and specificity and fit hierarchical summary receiver-operating characteristic curves. We also performed sensitivity analysis using different antibodies to investigate potential heterogeneity. Twelve studies consisting of a total of 3754 NSCLC specimens were analyzed. When we defined 1+/2+/3+, 2+/3+, and 3+ as ALK positive, we found the sensitivities to be 99% (95% confidence interval [CI], 97%-100%), 86% (95% CI, 73%-93%), and 56% (95% CI, 36%-74%) and the specificities to be 98% (95% CI, 95%-99%), 99% (95% CI, 99%-100%), and 100% (95% CI, 100%-100%), respectively. We demonstrated that when defining 3+ as positive and 0 as negative the sensitivity was 99% and specificity was 100%. In our sensitivity analysis, we found the sensitivity of D5F3 and 5A4 antibodies to be much higher than that of ALK1. We concluded that IHC scores 0 and 3+ were nearly 100% concordant with FISH-negative and FISH-positive status, respectively. However, IHC scores 1+ and 2+ might require further confirmatory testing by FISH assay. IHC assay using D5F3 and 5A4 antibodies reliably detected NSCLC with ALK rearrangement and may be useful as a screening method to identify these tumors.

Culture and Drug Profiling of Patient Derived Malignant Pleural Effusions for Personalized Cancer Medicine

INTRODUCTION

The use of patients' own cancer cells for in vitro selection of the most promising treatment is an attractive concept in personalized medicine. Human carcinoma cells from malignant pleural effusions (MPEs) are suited for this purpose since they have already adapted to the liquid environment in the patient and do not depend on a stromal cell compartment. Aim of this study was to develop a systematic approach for the in-vitro culture of MPEs to analyze the effect of chemotherapeutic as well as targeted drugs.

METHODS

MPEs from patients with solid tumors were selected for this study. After morphological and molecular characterization, they were cultured in medium supplemented with patient-derived sterile-filtered effusion supernatant. Growth characteristics were monitored in real-time using the xCELLigence system. MPEs were treated with a targeted therapeutic (erlotinib) according to the mutational status or chemotherapeutics based on the recommendation of the oncologists.

RESULTS

We have established a robust system for the ex-vivo culture of MPEs and the application of drug tests in-vitro. The use of an antibody based magnetic cell separation system for epithelial cells before culture allowed treatment of effusions with only moderate tumor cell proportion. Experiments using drugs and drug-combinations revealed dose-dependent and specific growth inhibitory effects of targeted drugs.

CONCLUSIONS

We developed a new approach for the ex-vivo culture of MPEs and the application of drug tests in-vitro using real-time measuring of cell growth, which precisely reproduced the effect of clinically established treatments by standard chemotherapy and targeted drugs. This sets the stage for future studies testing agents against specific targets from genomic profiling of metastatic tumor cells and multiple drug-combinations in a personalized manner.

Common Fluorescence In Situ Hybridization Applications in Cytology

Context.—

Fluorescence in situ hybridization (FISH) is a well-established method for detection of genomic aberrations in diagnostic, prognostic, and predictive marker testing.

Objective.—

To review common applications of FISH in cytology.

Data Sources.—

The published literature was reviewed.

Conclusions.—

Cytology is particularly well suited for all kinds of FISH applications, which is highlighted in respiratory tract cytology with an increasing demand for predictive FISH testing in lung cancer. Fluorescence in situ hybridization is the gold standard for detection of predictive anaplastic lymphoma kinase gene (ALK) rearrangements, and the same evaluation criteria as in histology apply to cytology. Several other gene rearrangements, including ROS proto-oncogene 1 receptor tyrosine kinase (ROS1), are becoming clinically important and share the same underlining cytogenetic mechanisms with ALK. MET amplification is one of the most common mechanisms of acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors and can be targeted by crizotinib. As genomic aberrations are a hallmark of malignant cells, FISH is a valuable objective ancillary diagnostic tool. In urinary tract cytology, atypical urothelial cells equivocal for malignancy are a common diagnostic dilemma and multitarget FISH can help clarify such cells. Diagnosis of malignant mesothelioma remains one of the most challenging fields in effusion cytology, and ancillary FISH is useful in establishing the diagnosis. Fluorescence in situ hybridization is a morphology-based technique, and the prerequisite for reliable FISH results is a targeted evaluation of the cells in question (eg, cancer or atypical cells). Cytopathologists and cytotechnicians should therefore be involved in molecular testing in order to select the best material and to provide their morphologic expertise.

High concordance of ALK rearrangement between primary tumor and paired metastatic lymph node in patients with lung adenocarcinoma

BACKGROUND

Lung cancer has heterogeneous features. It remains unclear whether ALK rearrangement was distributed heterogeneously in tumor from different anatomic sites. To address this issue, we investigate the concordance of ALK rearrangement between primary tumors and paired metastatic lymph nodes in pulmonary adenocarcinoma patients.

METHODS

From Sep 2013 to May 2014, resectable lung adenocarcinoma patients with EGFR wildtype and paired metastatic lymph nodes from Tongji University affiliated Shanghai pulmonary hospital were selected into this study. An auto-mated Ventana ALK with clone D5F3 antibody immunohistochemistry (IHC) and reverse transcriptase-polymerase chain reaction (RT-PCR) were used to detected ALK rearrangement. Discordant cases between IHC and RT-PCR were further validated by fluorescence in situ hybridization (FISH).

RESULTS

A total of 101 patients were enrolled into this study with a median age of 60 years old (range, 35-78 years). ALK rearrangement was found in 20 primary lesions, while in 18 paired metastatic lymph nodes. ALK rearrangement was more frequently happened in younger (P<0.001), Nonsmokers (P=0.012), high-stage disease (P=0.021) and predominantly solid growth pattern (P=0.024). The concordance rate between primary tumor and paired metastatic lymph nodes was 98%. Two patients with ALK rearrangement on primary tumor didn't show ALK gene fusion on paired metastatic lymph nodes. Sixty-eight cases had more than two stations of metastatic lymph nodes. ALK rearrangement in the different station of metastatic lymph nodes of the same patient was consistent.

CONCLUSIONS

High concordant rate of ALK rearrangement between primary tumors and paired metastatic lymph nodes were found in this study. The authors concluded that specimens from metastatic lesions and primary tumors are equally suitable for detection ALK rearrangement.

Screening for ALK Rearrangements in Lung Cancer: Time for a New Generation of Diagnostics?

A study reported in this issue of The Oncologist examined the utility of next-generation sequencing (NGS) in detecting ALK rearrangements. NGS may one day become the standard initial test for molecular genotyping of patients with advanced cancers, and this new generation of ALK diagnostics is a welcome addition to the current screening repertoire.