ALK Status Testing in Non–Small-Cell Lung Carcinoma by FISH on ThinPrep Slides with Cytology Material

Advances in diagnostic liquid-based cytology

Liquid-based cytology (LBC) has changed the landscape of gynaecological cytology. A growing demand exists for LBC in diagnostic cytology, particularly for ancillary testing, such as immunocytochemistry and molecular testing. Ancillary testing solely based on conventional preparation (CP) methods remains challenging. Recently, the increased demand for specialist testing and minimally invasive techniques, such as endoscopic ultrasonography fine-needle aspiration, to obtain cellular samples has led to an increasing demand for ancillary testing on cytology LBC supernatant, slides and cell block (CB). This facilitates the diagnosis and prognosis in cytology samples enabling personalized treatment. An understanding of the history and future prospects of LBC is crucial for its application in routine diagnostics by cytopathologists and cytotechnologists. In this review, we initiated an internet search using the keyword 'liquid-based cytology', and we conducted a literature review to discuss the usefulness of combined diagnosis of LBC and CP, immunocytochemistry and molecular testing and assessed the quality of nucleic acids in diagnostic LBC. High-quality and cell-rich diagnostic LBC surpassed the CP method alone in terms of reliability and versatility of ancillary testing in cytological diagnosis. Conclusively, diagnostic LBC lends itself to various new technologies and is expected to continue evolving with innovations in the future.

Role of cytoblock on pleural effusion for diagnosis of malignant disease

BACKGROUND

Thoracocentesis of pleural effusion is a simple technique for pleural fluid examination through cytology. In addition to cytological examination to assess the nature of pleural fluid content, we can also perform more detailed examinations through cytoblocks of residual fluid. These paraffin-embedded cytoblock samples are important because we can perform examinations as in other bioptic samples. In these samples, immunohistochemical and molecular analyses can be performed.

METHODS

Two hundred fifty-five cytological samples from patients with pleural effusion were examined. In cases in which the presence of malignant cells was identified in the cytological examination, as well as cases that were suspicious but not definitive for the presence of a malignant effusion, a cytoblock was prepared. Histological examination and immunohistochemical analysis were performed.

RESULTS

Among 255 cases with pleural effusion, 152 had the presence of malignant cells and 6 cases were suspicious, but uncertain for the presence of malignant cells, while 86 cases had inflammatory pleural effusion or other pathologies but were not malignant. After histological analysis of the cytoblock and immunohistochemical analysis, we identified 82 malignant tumors of the lung, 8 malignant tumors of the gastrointestinal tract, 15 malignant tumors of the breast, and 6 malignant tumors of the female genital tract, as well as 24 tumors of undetermined origin.

CONCLUSIONS

Cytoblocks are important for the diagnosis of the primary nature of malignant pleural effusions. The highest importance is primary lung tumors, as well as those tumors in which the primary site of the tumor cannot be determined clinically.

Lymphoproliferative disorder involving body fluid: diagnostic approaches and roles of ancillary studies

Lymphocyte-rich effusions represent benign reactive process or neoplastic condition. Involvement of lymphoproliferative disease in body cavity is not uncommon, and it often causes diagnostic challenge. In this review, we suggest a practical diagnostic approach toward lymphocyte-rich effusions, share representative cases, and discuss the utility of ancillary tests. Cytomorphologic features favoring neoplastic condition include high cellularity, cellular atypia/pleomorphism, monomorphic cell population, and frequent apoptosis, whereas lack of atypia, polymorphic cell population, and predominance of small T cells usually represent benign reactive process. Involvement of non-hematolymphoid malignant cells in body fluid should be ruled out first, followed by categorization of the samples into either small/medium-sized cell dominant or large-sized cell dominant fluid. Small/medium-sized cell dominant effusions require ancillary tests when either cellular atypia or history/clinical suspicion of lymphoproliferative disease is present. Large-sized cell dominant effusions usually suggest neoplastic condition, however, in the settings of initial presentation or low overall cellularity, ancillary studies are helpful for more clarification. Ancillary tests including immunocytochemistry, in situ hybridization, clonality test, and next-generation sequencing can be performed using cytologic preparations. Throughout the diagnostic process, proper review of clinical history, cytomorphologic examination, and application of adequate ancillary tests are key elements for successful diagnosis.

Multiplex fluorescence in situ hybridization testing for anaplastic lymphoma kinase and c-ros oncogene 1 gene rearrangements on cytology smears in lung adenocarcinomas: comparative study with formalin-fixed paraffin-embedded sections

INTRODUCTION

Multiplex anaplastic lymphoma kinase (ALK)/c-ros oncogene 1 (ROS1) fluorescence in situ hybridization (FISH) probes conserve tissue by analyzing both ALK and ROS1 gene rearrangements (ALK-R/ROS1-R) in a single test. The positivity cutoffs have been validated on formalin-fixed, paraffin-embedded (FFPE) tissue sections and not tested on non-cell block (CB) cytology preparations. We sought to validate non-CB cytology preparations for the detection of ALK-R/ROS1-R using multiplex ALK/ROS1 FISH probes by comparing the results with matched FFPE results.

MATERIALS AND METHODS

During the 3.5-year study period, FISH using the FlexISH ALK/ROS1 DistinguISH Probe (ZytoVision) was performed in non-CB cytology preparations of patients for whom FISH on FFPE sections was performed.

RESULTS

A total of 20 patients had one or more non-CB cytology preparations (n = 27) suitable for FISH analysis. These comprised direct smears (n = 17), smears from centrifuged effusion pellets (n = 8), cytospin smears (n = 1), and biopsy imprint smears (n = 1). These had been fixed in 95% ethanol (n = 18) or air dried (n = 9), and stained with Papanicolaou (n = 14), May-Grünwald-Giemsa (n = 9), immunocytochemistry (n = 3), or hematoxylin and eosin (n = 1). The median archival time was 1 year. Successful FISH results were achieved in 14 samples (6 with ALK-R, 2 with ROS1-R, 6 negative) and were concordant with the FFPE FISH results for 13 of 14 cases. The single case with discordant results between cytology and FFPE FISH showed ALK-R on cytology concordant with positive ALK D5F3 companion diagnostics assay results and was considered a false-negative FFPE FISH result. FISH failure occurred mainly in the older archived slides because of overdigestion (n = 5), hybridization failure (n = 5), or excessive background fluorescence (n = 3).

CONCLUSIONS

Non-CB cytology smears are highly suitable for multiplex FISH analysis with 100% concordance with FFPE FISH and/or ALK D5F3 companion diagnostics assay results.

Lung cancer staging, the established role of bronchoscopy

PURPOSE OF REVIEW

Lung cancer is the leading cause of cancer-related deaths worldwide. In the absence of distant metastases, accurate mediastinal nodal staging determines treatment approaches to achieve most favourable outcomes for patients. Mediastinal staging differentiates N0/N1 disease from N2/N3 in surgical candidates. Likewise, presence of nodal involvement in nonsurgical candidates who are being considered for stereotactic body radiation therapy is also critical. This review article seeks to discuss the current options available for mediastinal staging in nonsmall cell lung cancer (NSCLC), particularly the role of bronchoscopy.

RECENT FINDINGS

Although several techniques are available to stage the mediastinum, bronchoscopy with EBUS-TBNA with or without EUS-FNA appears to be superior in most clinical situations based on its ability to concomitantly diagnose and stage at once, safety, accessibility to the widest array of lymph node stations, cost and low risk of complications. However, training and experience are required to achieve consistent diagnostic accuracy with EBUS-TBNA.

SUMMARY

EBUS-TBNA with or without EUS-FNA is considered the modality of choice in the diagnosis and staging of NSCLC in both surgical and nonsurgical candidates.

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.

Oncogenic gene transcripts detection by FISH on liquid-based cytology slides of 338 advanced lung cancer patients

INTRODUCTION

Oncogenic gene transcripts in advanced lung cancer are a strong indication for targeted therapy. Cytology specimens are often the only materials available for oncogenic fusion analysis. This prospective study is to evaluate the feasibility of anaplastic lymphoma kinase (ALK) gene rearrangements, ROS oncogene 1 (ROS-1), and c-mesenchymal-epidermal transformation (c-MET) detected by fluorescence in situ hybridization (FISH) using liquid-based cytology (LBC) slides.

MATERIALS AND METHODS

Consecutive cytology specimens including fine-needle aspiration biopsy (FNAB) and serous effusions from 338 advanced lung cancer patients were collected between March 1, 2015, and July 6, 2016. The correlation between ALK, ROS-1, c-MET, and other common driver gene abnormalities and the therapeutic response to crizotinib in ALK-positive patients were also evaluated.

RESULTS

ALK fusion transcripts were detected in 31 of 338 patients (9.17%). Twenty-two of the 31 ALK-positive patients were treated with crizotinib at our institution (2 were lost to follow-up), and the overall response rate was 75.0 % (15 of 20); disease control rate was 90.0% (18 of 20). FISH analyses for ROS-1 and c-MET were performed on 75 and 73 patients, respectively, and showed 3 patients positive for ROS-1 and 3 positive for c-MET. These positive cases were all ALK-negative.

CONCLUSION

For patients with advanced lung cancer, LBC slides are suitable for detecting oncogenic gene transcripts, and the results can provide a reliable guideline for targeted therapy.

EGFR Mutation Analysis in Non-small Cell Lung Carcinoma from Tissue Samples Using the Fully Automated Idylla™ qPCR System

The introduction of tyrosine-kinase inhibitors (TKI) targeting specific EGFR mutations for the treatment non-small cell lung cancer patients (NSCLC) dramatically increased the clinical outcome in a subset of patients harboring specific activating EGFR mutations. Three different generations of TKI have been developed until now, demonstrating increasing progression-free survival as well as overall survival. However, to benefit of the treatment, the analysis of the genomic content of each patient is mandatory. Additionally, resistance mutations are prevalent and occur frequently and rapidly during treatment. Therefore, tests to detect EGFR mutations at initial diagnosis as well as during treatment, e.g., from liquid biopsies, have been developed and implemented in clinical daily practice for theranostic purpose.As EGFR mutation testing has to be highly reliable, fast, and easy to perform, the automatic qPCR system Idylla™ has been developed and implemented for clinical mutation testing from tissue samples and soon from circulating free DNA. Therefore, we here describe how the Idylla™ system can be used for the analysis of EGFR mutations in NSCLC patients. Importantly, as the results are massively influenced by the preanalytical steps, we also provide information on the correct sample selection to avoid nonconclusive results.

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.

Collection and Handling of Thoracic Small Biopsy and Cytology Specimens for Ancillary Studies: Guideline From the College of American Pathologists in Collaboration With the American College of Chest Physicians, Association for Molecular Pathology, American Society of Cytopathology, American Thoracic Society, Pulmonary Pathology Society, Papanicolaou Society of Cytopathology, Society of Interventional Radiology, and Society of Thoracic Radiology

CONTEXT.—

The need for appropriate specimen use for ancillary testing has become more commonplace in the practice of pathology. This, coupled with improvements in technology, often provides less invasive methods of testing, but presents new challenges to appropriate specimen collection and handling of these small specimens, including thoracic small biopsy and cytology samples.

OBJECTIVE.—

To develop a clinical practice guideline including recommendations on how to obtain, handle, and process thoracic small biopsy and cytology tissue specimens for diagnostic testing and ancillary studies.

METHODS.—

The College of American Pathologists convened an expert panel to perform a systematic review of the literature and develop recommendations. Core needle biopsy, touch preparation, fine-needle aspiration, and effusion specimens with thoracic diseases including malignancy, granulomatous process/sarcoidosis, and infection (eg, tuberculosis) were deemed within scope. Ancillary studies included immunohistochemistry and immunocytochemistry, fluorescence in situ hybridization, mutational analysis, flow cytometry, cytogenetics, and microbiologic studies routinely performed in the clinical pathology laboratory. The use of rapid on-site evaluation was also covered.

RESULTS.—

Sixteen guideline statements were developed to assist clinicians and pathologists in collecting and processing thoracic small biopsy and cytology tissue samples.

CONCLUSIONS.—

Based on the systematic review and expert panel consensus, thoracic small specimens can be handled and processed to perform downstream testing (eg, molecular markers, immunohistochemical biomarkers), core needle and fine-needle techniques can provide appropriate cytologic and histologic specimens for ancillary studies, and rapid on-site cytologic evaluation remains helpful in appropriate triage, handling, and processing of specimens.

Small but powerful: the promising role of small specimens for biomarker testing

Emphasis on the use of small specimens for biomarker testing to provide prognostic and predictive information for guiding clinical management for patients with advanced-stage cancer has been increasing. These biomarker tests include molecular analysis, cytogenetic tests, and immunohistochemical assays. Owing to the limited nature of the cellular material procured in these small specimens, which are collected using minimally invasive techniques (ie, fine needle aspiration and core needle biopsy), pathologists have been required to triage these samples judiciously and provide the clinically relevant genomic information required for patient care. Awareness of the advantages and limitations of these specimen preparations and the specific preanalytic requirements for the testing methods will help pathologists to develop optimal strategies to maximize the chances of effectively using these samples for comprehensive diagnostic and relevant biomarker testing.

Analysis of Genetic Alterations in Tunisian Patients with Lung Adenocarcinoma

The identification of the mutations that drive lung cancer have furnished new targets for the treatment of non-small cell lung cancer (NSCLC) and led to the development of targeted therapies such as tyrosine kinase inhibitors that are used to combat the molecular changes promoting cancer progression. Furthermore, biomarkers identified from gene analysis can be used to detect early lung cancer, determine patient prognosis, and monitor response to therapy. In the present study we analyzed the molecular profile of seventy-three Tunisian patients with lung adenocarcinoma (LAD). Mutational analyses for EGFR and KRAS were performed using direct sequencing, immunohistochemistry or MassARRAY. Anaplastic lymphoma kinase (ALK) rearrangement was evaluated by immunohistochemistry using the D5F3 clone, and p53 expression was also assessed. The median age of patients at diagnosis was 61 years (range 23-82 years). Using different methodologies, EGFR mutations were found in 5.47% of patients and only exon 19 deletions "E746-A750 del" were detected. KRAS mutations were present in 9.58% of cases, while only one patient was ALK-positive. Moreover, abnormal immunostaining of p53 was detected in 56.16% of patients. In conclusion, the detected rates of EGFR and KRAS mutation and ALK rearrangement were lower than those found in European and Asian countries, whereas, abnormal p53 expression was slightly more frequent. Furthermore, given the small sample size of this study, a more comprehensive analysis of this patient set is warranted.

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.

Role of Ancillary Techniques in Fluid Cytology

The cytologic evaluation of serous effusions may be challenging for a number of reasons. Distinction of benign, reactive conditions from malignancy represents the main focus when examining these specimens. The morphologic diagnosis of malignancy may be difficult due to the relative paucity of abnormal cells. In other situations, cellularity is not an issue, but the ability to confidently identify a second, foreign (i.e., tumor) population within a background mesothelial cells on the basis of cytomorphologic features alone may pose problems. Cases with definitive morphologic evidence of malignancy may require additional studies in order to determine the tumor subtype and, in the case of carcinoma, the primary site of origin. Cases in which a definitive and precise diagnosis of malignancy is made may be optimal candidates for further molecular testing in order to gain prognostic information and guide personal therapeutic decisions. Finally, while an inflammatory or infectious condition can be suggested on the basis of cellular components and associated background elements, the identification of causative agent(s) may be difficult without additional studies. In all of these situations, the use of ancillary studies and techniques is critical; their utility and appropriate application are the subject of this review.

Overview of Molecular Testing of Cytology Specimens

OBJECTIVE

Utilizing cytology specimens for molecular testing has attracted increasing attention in the era of personalized medicine. Cytology specimens are clinically easier to access. The samples can be quickly and completely fixed in a very short time of fixation before tissue degradation occurs, compared to hours or days of fixation in surgical pathology specimens. In addition, cytology specimens can be fixed without formalin, which can significantly damage DNA and RNA. All these factors contribute to the superb quality of DNA and RNA in cytology specimens for molecular tests.

STUDY DESIGN

We summarize the most pertinent information in the literature regarding molecular testing in the field of cytopathology.

RESULTS

The first part focuses on the types of cytological specimens that can be used for molecular testing, including the advantages and limitations. The second section describes the common molecular tests and their clinical application.

CONCLUSION

Various types of cytology specimens are suitable for many molecular tests, which may require additional clinical laboratory validation.

RNA Analysis as a Tool to Determine Clinically Relevant Gene Fusions and Splice Variants

CONTEXT

- Technologic advances have contributed to the increasing relevance of RNA analysis in clinical oncology practice. The different genetic aberrations that can be screened with RNA include gene fusions and splice variants. Validated methods of identifying these alterations include fluorescence in situ hybridization, immunohistochemistry, reverse transcription-polymerase chain reaction, and next-generation sequencing, which can provide physicians valuable information on disease and treatment of cancer patients.

OBJECTIVE

- To discuss the standard techniques available and new approaches for the identification of gene fusions and splice variants in cancer, focusing on RNA analysis and how analytic methods have evolved in both tissue and liquid biopsies.

DATA SOURCES

- This is a narrative review based on PubMed searches and the authors' own experiences.

CONCLUSIONS

- Reliable RNA-based testing in tissue and liquid biopsies can inform the diagnostic process and guide physicians toward the best treatment options. Next-generation sequencing methodologies permit simultaneous assessment of molecular alterations and increase the number of treatment options available for cancer patients.

The diagnosis of non-small cell lung cancer in the molecular era

Lung carcinoma is the leading cause of cancer mortality for both genders in the United States and throughout the world. Many of these tumors are being diagnosed with minimally invasive means resulting in small samples. There is a need to extract an increasing amount of therapeutic and prognostic information from progressively smaller samples. Collaboration among clinicians and pathologists is needed to produce a comprehensive final diagnosis in patients with lung cancer. This collaboration facilitates triage of small samples for ancillary studies including molecular testing. What follows represents a review of the current required testing for lung cancer specimens, an example of an algorithm currently employed at the Cleveland Clinic so that all required tests can be performed even on the smallest of specimens and suggestions on how pathologists may approach this new era of "doing more with less".

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.

Sampling Utility of the Convex Probe Endobronchial Ultrasound Visible Intrapulmonary Lesion

BACKGROUND

The value of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the mediastinal staging of lung cancer has been well established. However, data regarding its utility in the diagnosis of intrapulmonary lesions has been sparse. This study assesses the sampling utility of convex probe EBUS-visible intrapulmonary lesions not visualized by the white-light bronchoscopy.

METHODS

A retrospective analysis of EBUS-TBNA of EBUS-visible intrapulmonary lesions was performed between January 2010 and March 2015. Patients with visible endobronchial lesions by white-light bronchoscopy were excluded from analysis.

RESULTS

Among 108 procedures, the diagnostic yield of EBUS-TBNA for EBUS-visible intrapulmonary lesions was 87%. Following diagnoses were established: lung cancer (73/67.6%), lung metastases (10/9.2%), infection (5/4.6%), lymphoma (1/<1%), sarcoma/spindle cell sarcoma or neoplasm (3/2.8%), unspecified malignancy (1<1%), and hamartoma (1/<1%). EBUS-TBNA was nondiagnostic in 14 (13%); among these, 9 turned out to have benign disease based on additional bronchoscopy samples or other testing and/or follow-up imaging. Five were ultimately diagnosed with a malignant condition: lymphoma (1), epithelioid hemangioendothelioma (1), and non-small cell lung cancer (3). The sensitivity and the negative predicted value of EBUS-TBNA for differentiating malignancy from benign disease was 94.7% and 75%, respectively, while the accuracy for diagnosing the neoplastic disease was 95.3%. There was one major bleeding requiring bronchial artery embolization and 1 pneumothorax requiring chest tube drainage.

CONCLUSION

EBUS-TBNA is safe and effective in the diagnosis of EBUS-visible intrapulmonary lesions. It should be considered as the diagnostic test of choice in patients with these lesions undergoing EBUS-TBNA for the staging of suspected lung cancer.

Advances in Molecular Testing Techniques in Cytologic Specimens

There has been a paradigm shift in the practice of cytopathology with the advent of highly sensitive molecular tests using small amounts of tissue that can provide diagnostic, prognostic, and predictive information for clinical management. The cytopathologist plays a key role in providing a timely and accurate diagnosis as well as ensuring appropriate processing and handling of the specimen and judicious triaging of the tissue for molecular testing that guide therapeutic decisions. As the era of "precision medicine" continues to evolve and expand, cytopathology remains a dynamic field with advances in the practice of molecular cytopathology providing new paradigms in clinical care.

Efficacy of D5F3 IHC for detecting ALK gene rearrangement in NSCLC patients: a systematic review and meta-analysis

We conducted a pooled analysis comparing the efficacy of an immunohistochemistry (IHC) assay using the D5F3 antibody with that of fluorescence in situ hybridization (FISH) for detecting ALK gene rearrangement in NSCLC patients. A total of 32 studies involving 5805 samples were included in this review. Pooled sensitivity for D5F3 IHC was 0.97 (95%CI: 0.93-0.98), specificity was 0.99 (95%CI: 0.98-1.00), PLR was 119.20 (95%CI: 57.79-245.89), NLR was 0.03 (95%CI: 0.02-0.07), DOR was 3526.66 (95%CI: 1344.71-9249.03), and AUROC was 1.00 (95%CI: 0.99-1.00). Meta-regression revealed that specimen type was a source of heterogeneity for specificity, and specimen type and FISH signal distance were sources of heterogeneity in the joint model. Subgroup analysis revealed that sensitivity and specificity were higher when the FISH signal distance standard was ≥ 2 than when it was ≥ 1. Sensitivity was higher for tumor specimens than for cell specimens; specificity was higher for cell specimens than for tumor specimens. In conclusion, the D5F3 IHC assay was nearly as effective as FISH for detection of ALK gene rearrangement in NSCLC patients.

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.

ALK Status Assessment with Liquid Biopsies of Lung Cancer Patients

Patients with advanced stage non-small cell lung carcinoma (NSCLC) harboring an anaplastic lymphoma kinase ALK gene rearrangement, detected from a tissue sample, can benefit from targeted ALK inhibitor treatment. However, while treatment is initially effective in most cases, relapse or progression occurs due to different resistance mechanisms including mutations in the tyrosine kinase domain of echinoderm microtubule-associated protein-like 4 (EML44)-ALK. The liquid biopsy concept has recently radically changed the clinical care of NSCLC patients, in particular for those harboring an epidermal growth factor receptor (EGFR) gene mutation. Therefore, liquid biopsy is an alternative or complementary method to tissue biopsy for the detection of some resistance mutations in EGFR arising during tyrosine kinase inhibitor treatment. Moreover, in some frail patients, or if the tumor lesion is not accessible to a tissue biopsy, a liquid biopsy can also detect some activating mutations in EGFR on initial assessment. Recent studies have evaluated the possibility of also using a liquid biopsy approach to detect an ALK rearrangement and/or the emergence during inhibitor treatment of some resistance mutations in ALK. These assessments can be performed by studying circulating tumor cells by fluorescent in situ hybridization and by immunocytochemistry and/or after the isolation of RNA from plasma samples, free or associated with platelets. Thus, the liquid biopsy may be a complementary or sometimes alternative method for the assessment of the ALK status in certain NSCLC patients, as well as a non-invasive approach for early detection of ALK mutations. In this review, we highlight the current data concerning the role of the liquid biopsy for the ALK status assessment for NSCLC patients, and we compare the different approaches for this evaluation from blood samples.

ALK in Non-Small Cell Lung Cancer (NSCLC) Pathobiology, Epidemiology, Detection from Tumor Tissue and Algorithm Diagnosis in a Daily Practice

Patients with advanced-stage non-small cell lung carcinoma (NSCLC) harboring an ALK rearrangement, detected from a tissue sample, can benefit from targeted ALK inhibitor treatment. Several increasingly effective ALK inhibitors are now available for treatment of patients. However, despite an initial favorable response to treatment, in most cases relapse or progression occurs due to resistance mechanisms mainly caused by mutations in the tyrosine kinase domain of ALK. The detection of an ALK rearrangement is pivotal and can be done using different methods, which have variable sensitivity and specificity depending, in particular, on the quality and quantity of the patient’s sample. This review will first highlight briefly some information regarding the pathobiology of an ALK rearrangement and the epidemiology of patients harboring this genomic alteration. The different methods used to detect an ALK rearrangement as well as their advantages and disadvantages will then be examined and algorithms proposed for detection in daily routine practice.

Use of fluorescent in-situ hybridisation in salivary gland cytology: A powerful diagnostic tool

OBJECTIVE

Salivary gland cytology is challenging because it includes a diversity of lesions and a wide spectra of tumours. Recently, it has been reported that many types of salivary gland tumours have specific molecular diagnostic signatures that could be identified by fluorescent in-situ hybridisation (FISH). The aim of the present study was to demonstrate the feasibility and efficiency of FISH on routine cytological salivary gland smears.

METHODS

FISH was conducted on 37 cytological salivary gland smears from 34 patients. According to the cytological diagnosis suspected, MECT1/MAML2 gene fusion and rearrangements of PLAG1, MYB, or ETV6 were analysed. The presence and percentages of cells that had gene rearrangements were evaluated. Results were compared with the histological surgical samples, available from 26 patients.

RESULTS

The PLAG1 rearrangement was observed in 12/20 (60%) cases of pleomorphic adenoma. MECT1/MAML2 gene fusion was observed in 1:2 mucoepidermoid carcinomas but was not observed in five other tumours (two pleomorphic adenomas, one Warthin's tumour, one mammary analogue secretory carcinoma [MASC] and one cystic tumour). MYB rearrangement was observed in 4/4 adenoid cystic carcinomas. ETV6-gene splitting identified one MASC.

CONCLUSION

Overall, FISH had a specificity of 100% and a sensitivity of 66.7%. When FISH and cytological analyses were combined, the overall sensitivity was increased to 93.3%. It can thus be concluded that when the FISH analysis is positive, the extent of surgery could be determined with confidence pre-operatively without needing a diagnosis from a frozen section.

ALK protein expression in pulmonary adenocarcinoma of Tunisian patients

BACKGROUND

It is now necessary to determine ALK status in order to use targeted therapy.

AIM

herein, we assess immunohistochemical profile of ALK protein in a series of Tunisian patients with pulmonary adenocarcinoma.

MATERIALS AND METHODS

ALK protein expression was studied applying the D5F3 antibody with a fully automated Ventana CDx technique on a series of 19 patients.

RESULTS

Positive ALK expression was found in one case (5.2%) corresponding to a papillary adenocarcinoma which showed a strong granular and homogenous cytoplasmic staining. The patient was a 30-years-old woman.

CONCLUSION

The frequency of positive ALK expression based on immunohistochemistry in our series was similar to that reported in the world literature.

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.

Next-generation sequencing of liquid-based cytology non-small cell lung cancer samples

BACKGROUND

The detection of mutated epidermal growth factor receptor (EGFR) in non-small cell lung cancer (NSCLC) with residual cell pellets derived from liquid-based cytology (LBC) samples (eg, endoscopic ultrasound-guided fine-needle aspiration) has been validated with allele-specific polymerase chain reaction. The aim of this study was to validate next-generation sequencing (NGS) technology for detecting gene mutations with residual cell pellets from LBC.

METHODS

Archived DNA extracted from LBC samples of adenocarcinoma stored in PreservCyt with a known EGFR mutation status was retrieved. Genomic DNA was multiplex-amplified and enriched with Ion AmpliSeq Cancer Hotspot Panel v2 chemistry and the OneTouch 2 instrument; this was followed by semiconductor sequencing on the Ion Personal Genome Machine platform. The mutation hotspots of 6 NSCLC-related genes (BRAF, EGFR, ERBB2, KRAS, MET, and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α [PIK3CA]) were analyzed with NextGENe and Torrent Suite bioinformatics tools.

RESULTS

The commonly identified EGFR sequence changes, including 4 L858R mutations, 3 exon 19 deletions, and 1 exon 20 insertion, were in 100% concordance between the assay platforms. Less common NSCLC variants were also found in the mutation hotspots of ERBB2, KRAS, MET, and PIK3CA genes.

CONCLUSIONS

NSCLC mutation analysis using NGS can be successfully performed on residual cell pellets derived from LBC samples. This approach allows the simultaneous examination of multiple mutation hotspots in a timely manner to improve patient care. Cancer Cytopathol 2017;125:178-187. © 2016 American Cancer Society.

Inconsistent results in the analysis of ALK rearrangements in non-small cell lung cancer

BACKGROUND

Identification of targetable EML4-ALK fusion proteins has revolutionized the treatment of a minor subgroup of non-small cell lung cancer (NSCLC) patients. Although fluorescence in situ hybridization (FISH) is regarded as the gold standard for detection of ALK rearrangements, ALK immunohistochemistry (IHC) is often used as screening tool in clinical practice. In order to unbiasedly analyze the diagnostic impact of such a screening strategy, we compared ALK IHC with ALK FISH in three large representative Swedish NSCLC cohorts incorporating clinical parameters and gene expression data.

METHODS

ALK rearrangements were detected using FISH on tissue microarrays (TMAs), including tissue from 851 NSCLC patients. In parallel, ALK protein expression was detected using IHC, applying the antibody clone D5F3 with two different protocols (the FDA approved Ventana CDx assay and our in house Dako IHC protocol). Gene expression microarray data (Affymetrix) was available for 194 patients.

RESULTS

ALK rearrangements were detected in 1.7 % in the complete cohort and 2.0 % in the non-squamous cell carcinoma subgroup. ALK protein expression was observed in 1.8 and 1.4 % when applying the Ventana assay or the in house Dako protocol, respectively. The specificity and accuracy of IHC was high (> 98 %), while the sensitivity was between 69 % (Ventana) and 62 % (in house Dako protocol). Furthermore, only 67 % of the ALK IHC positive cases were positive with both IHC assays. Gene expression analysis revealed that 6/194 (3 %) tumors showed high ALK gene expression (≥ 6 AU) and of them only three were positive by either FISH or IHC.

CONCLUSION

The overall frequency of ALK rearrangements based on FISH was lower than previously reported. The sensitivity of both IHC assays was low, and the concordance between the FISH and the IHC assays poor, questioning current strategies to screen with IHC prior to FISH or completely replace FISH by IHC.

Biomarker Testing in Lung Carcinoma Cytology Specimens: A Perspective From Members of the Pulmonary Pathology Society

The advent of targeted therapy in lung cancer has heralded a paradigm shift in the practice of cytopathology with the need for accurately subtyping lung carcinoma, as well as providing adequate material for molecular studies, to help guide clinical and therapeutic decisions. The variety and versatility of cytologic-specimen preparations offer significant advantages to molecular testing; however, they frequently remain underused. Therefore, evaluating the utility and adequacy of cytologic specimens is critical, not only from a lung cancer diagnosis standpoint but also for the myriad ancillary studies that are necessary to provide appropriate clinical management. A large fraction of lung cancers are diagnosed by aspiration or exfoliative cytology specimens, and thus, optimizing strategies to triage and best use the tissue for diagnosis and biomarker studies forms a critical component of lung cancer management. This review focuses on the opportunities and challenges of using cytologic specimens for molecular diagnosis of lung cancer and the role of cytopathology in the molecular era.

Recent advances in the pathology and molecular genetics of lung cancer: A practical review for cytopathologists

Lung cancer is one of the most common causes of cancer-related death worldwide. Better understanding of the molecular genetic characteristics of non-small cell lung carcinoma (NSCLC), particularly adenocarcinoma, has opened the opportunity for targeted therapies. With the different molecular abnormalities and the different responses to new targeted therapies based on the histological subtype of NSCLC, there came a need to further classify NSCLC into squamous cell carcinoma and adenocarcinoma, and to perform the appropriate molecular testing in these different subtypes to guide management decisions. Given that approximately 70% of lung cancer patients have only small biopsies or cytology specimens available, incorporating the testing of these specimens into the cytopathology laboratory has been crucial. Herein, we review current concepts and recommendations on NSCLC subtyping and molecular testing that are relevant for the cytopathology community.

Destaining of Diff-Quik stained cytologic smears is not necessary for the detection of anaplastic lymphoma kinase gene rearrangement in lung adenocarcinoma by fluorescence in situ hybridization

Background:

Anaplastic lymphoma kinase (ALK) gene rearrangement analysis by fluorescence in situ hybridization (FISH) is one of the standard molecular tests for targeted therapy of lung adenocarcinoma. However, insufficient cell block cellularity may impede molecular testing. A recent study showed that Diff-Quik (DQ) stained cytology smear is suitable for ALK by FISH.

Aims:

The aim of our study was to observe the impact of destaining intervals on the quality of FISH signals and determine if DQ smears without destaining would allow FISH analysis.

Materials and Methods:

Thirty-five DQ smears from 27 cases of lung adenocarcinoma were analyzed for ALK gene rearrangement by FISH. Twenty three DQ smears were destained for different intervals, including 30 s (13 cases), 1 min (6 cases), or 2 min (4 cases). Twelve DQ smears were not subjected to destaining. For further validation, FISH signals in 8 smears and 6 cell blocks were compared with the paired destained DQ smears. The signal quality was semi-quantified and analyzed with Chi-squared test.

Results:

Of the total 27 selected cases, three (11%) were positive for ALK gene rearrangement, whereas 24 (89%) were negative. FISH signal was satisfactory in all DQ smears. There was no significant difference in the quality of signal among smears with different destaining intervals (P = 0.55) or between smears with and without destaining (P = 0.41). DQ smears without destaining showed identical FISH results and similar or better signals as compared with paired destained smears and cell blocks in all cases.

Conclusions:

Duration of destaining intervals does not impact the quality of FISH signal on DQ smears. Destaining of DQ smears is not necessary for ALK by FISH.

The Utilization of Cytologic Fine-Needle Aspirates of Lung Cancer for Molecular Diagnostic Testing

In this era of precision medicine, our understanding and knowledge of the molecular landscape associated with lung cancer pathogenesis continues to evolve. This information is being increasingly exploited to treat advanced stage lung cancer patients with tailored, targeted therapy. During the management of these patients, minimally invasive procedures to obtain samples for tissue diagnoses are desirable. Cytologic fine-needle aspirates are often utilized for this purpose and are important not only for rendering diagnoses to subtype patients’ lung cancers, but also for ascertaining molecular diagnostic information for treatment purposes. Thus, cytologic fine-needle aspirates must be utilized and triaged judiciously to achieve both objectives. In this review, strategies in utilizing fine-needle aspirates will be discussed in the context of our current understanding of the clinically actionable molecular aberrations underlying non-small cell lung cancer and the molecular assays applied to these samples in order to obtain treatment-relevant molecular diagnostic information.

Ventana immunohistochemistry ALK (D5F3) detection of ALK expression in pleural effusion samples of lung adenocarcinoma

AIM

To evaluate the Ventana IHC ALK (D5F3) assay for detecting anaplastic lymphoma kinase (ALK) protein expression in pleural effusion samples.

METHODS

Historical, selected (wild-type EGFR, K-RAS) pleural effusion cytologic blocks of lung adenocarcinoma samples (Study 1) and unselected lung adenocarcinoma pleural effusion cytologic blocks (Study 2) were tested by Ventana IHC ALK (D5F3) assay. Quantitative real-time-PCR was used to verify immunohistochemistry results.

RESULTS

A total of 17 out of 100 (Study 1) and ten out of 104 (Study 2) pleural effusion samples were ALK expression positive by the Ventana IHC ALK (D5F3) assay. The ALK fusion results with immunohistochemistry and quantitative real-time-PCR had a concordance rate of 87.5% (κ = 0.886; p < 0.001).

CONCLUSION

The Ventana IHC ALK (D5F3) assay is a reliable tool for detecting ALK protein expression in pleural effusion samples.

Suitability of small bronchoscopic tumour specimens for lung cancer genotyping

BACKGROUND

Biomarker-driven clinical trials in advanced non-small cell lung cancer (NSCLC) usually accept biopsy specimens only, as cytology specimens are supposed to be more challenging due to low neoplastic cell content and suboptimal DNA quantity.

OBJECTIVES

We aimed to evaluate 2 aspects of bronchoscopic biopsy and cytology specimens: (1) the proportion of neoplastic cells and quantity of DNA extracted, and (2) the detection limit of the Scorpion amplification refractory mutation system on endoscopic samples obtained in daily clinical practice.

METHODS

We screened 679 patients with advanced-stage NSCLC for the presence of an activating EGFR mutation according to the guidelines of the European Society of Medical Oncology. Their diagnostic tumour tissue samples were characterized. A dilution experiment was performed to determine the minimal proportion of neoplastic cells for a reliable test result.

RESULTS

Surgical biopsies, bronchoscopic forceps biopsy samples and needle aspiration cytology specimens exhibited a median tumour cell proportion of 70 versus 30 versus 20% and a DNA quantity of 2,500 versus 1,610 versus 1,440 ng, respectively. The overall EGFR mutation rate was 11%, with no differences between different sample types. Dilution experiments showed that the detection limit depends on the type of mutation. A neoplastic cell content of at least 10 and 25% for exon 19 deletions and exon 21 L858R point mutation, respectively, was required for a true negative result.

CONCLUSIONS

Bronchoscopic forceps biopsy and needle aspiration cytology specimens are suitable for accurate EGFR mutation analysis using single-gene quantitative real-time polymerase chain reaction. Technologies with a better analytical sensitivity are evolving and should consider these endoscopic tumour specimens.

Cytology specimens offer an effective alternative to formalin-fixed tissue as demonstrated by novel automated detection for ALK break-apart FISH testing and immunohistochemistry in lung adenocarcinoma

BACKGROUND

Minimally invasive sampling by cytology or core needle biopsy often provides an initial diagnosis for treatment in patients with lung nodules. From these limited specimens, multiple molecular studies are frequently requested. Current guidelines from the US Food and Drug Administration recommend using formalin-fixed paraffin-embedded tissue sections for the detection of anaplastic lymphoma kinase (ALK) gene rearrangement by fluorescence in situ hybridization (FISH). The authors compared alcohol-fixed and formalin-fixed cytology specimens using a novel automated detection for ALK rearrangements by FISH and immunohistochemistry (IHC).

METHODS

ALK FISH testing was performed on 129 lung adenocarcinomas from 71 cytology cases and 58 biopsy/resection specimens using Papanicolaou staining with integrated cytomorphology. IHC with the ALK D5F3 antibody was performed on cases with residual material (88 of 129 cases).

RESULTS

The mean age of the patients was 66 years; there were 62 women and 67 men. ALK gene rearrangement was present in 4% of cytology specimens (3 of 71 specimens) and 7% of surgical specimens (4 of 58 specimens). FISH in 13 cases was technically unsuccessful. Of the 7 FISH-positive cases, only 2 cytology cases (4%) and 2 surgical cases (6%) were found to be positive with the ALK antibody, demonstrating 80% concordance. The one case found to be negative for ALK by IHC demonstrated a variant rearrangement of the ALK 2p23 gene locus by FISH.

CONCLUSIONS

The results of the current study validate the usefulness of alcohol-fixed and/or formalin-fixed cytology specimens for ALK rearrangement by a novel automated FISH method. IHC using the D5F3 antibody for ALK is specific in this limited cohort. The authors also demonstrated that alcohol-fixed cytology specimens can be used for ALK rearrangement by automated FISH, alone or in conjunction with IHC.

Is liquid-based cytology the magic bullet for performing molecular techniques?

OBJECTIVE

The role of pathology has evolved from the first microscopic definitions of diseases by Virchow to the new concept of molecular cytopathology. The management of diseases is now a multidisciplinary approach with the translation of morphological, imagery and molecular findings to therapeutic protocols. Obtaining the most reliable diagnostic material is the essential part of the medical management of patients.

STUDY DESIGN

Here, we try to gain a concise insight into the available data regarding the role of cytology in the application of molecular techniques, focusing on cancer cytopathology.

RESULTS

Obtaining cytological material is now feasible by different methods, and in some cases it is the only possible approach to a lesion which is not easily accessible for tissue sampling. The methods of obtaining cytological material have evolved in recent years in parallel with rapid advances in high-throughput molecular techniques, opening new windows for the diagnosis and management of diseases.

CONCLUSIONS

Different kinds of cytological material are reliable for the application of molecular techniques. Cytological material obtained in a liquid base has advantages such as the better preservation of cytomorphological features and the use of the remaining liquid for nucleic acid extraction even after long storage and the application of molecular methods.