Detection ofALKrearrangements in malignant pleural effusion cell blocks from patients with advanced non-small cell lung cancer: A comparison of Ventana immunohistochemistry and fluorescence in situ hybridization

Contemporary art of cell-block preparation: Overview

Cell blocks (CBs) are paraffin-embedded versions of cytology specimens. These versions are contrasted with tissues made from surgical pathology specimens of formalin-fixed paraffin-embedded (FFPE) tissue. CBs enable various elective ancillary studies of a range of specimens. These studies include the potential to perform molecular tests with the enhanced cytopathological interpretation. CBs are increasingly reported in cytology specimens. The enhanced role of CBs incorporates additives with new markers for immunohistochemistry (IHC), including the multicolored approach to IHC, and the subtractive coordinate immunoreactivity pattern. Even when archived material is retrospectively retrieved, CBs are a major tissue source for many supplementary studies. The CBs have been qualitatively and quantitatively improved. CBs are significant since they have increased molecular markers standardized on FFPE tissue. High-quality CBs can serve as useful additions to cytological smear preparations and touch imprint cytology. Most cytological specimens, such as fine-needle aspirations, cavitary effusion, washings, brushings, and gynecological and non-gynecological liquid specimens, may be used to produce CBs. This review deals with the CB-making process and discusses various historical limitations with an emphasis on recent advances.

Using patient-derived organoids to predict locally advanced or metastatic lung cancer tumor response: A real-world study

Predicting the clinical response to chemotherapeutic or targeted treatment in patients with locally advanced or metastatic lung cancer requires an accurate and affordable tool. Tumor organoids are a potential approach in precision medicine for predicting the clinical response to treatment. However, their clinical application in lung cancer has rarely been reported because of the difficulty in generating pure tumor organoids. In this study, we have generated 214 cancer organoids from 107 patients, of which 212 are lung cancer organoids (LCOs), primarily derived from malignant serous effusions. LCO-based drug sensitivity tests (LCO-DSTs) for chemotherapy and targeted therapy have been performed in a real-world study to predict the clinical response to the respective treatment. LCO-DSTs accurately predict the clinical response to treatment in this cohort of patients with advanced lung cancer. In conclusion, LCO-DST is a promising precision medicine tool in treating of advanced lung cancer.

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.

A Systematic Review of Companion Diagnostic Tests by Immunohistochemistry for the Screening of Alectinib-Treated Patients in ALK-Positive Non-Small Cell Lung Cancer

Companion diagnostic tests and targeted therapy changed the management of non-small cell lung cancer by diagnosing genetic modifications and enabling individualized treatment. The purpose of this systematic review is to assess the clinical applicability of companion diagnostic tests (IHC method) by comparing the effects of alectinib and crizotinib in patients with ALK-positive NSCLC. We searched for literature up to March 2022 in PubMed, Web of Science, Cochrane, and Google Scholar. The inclusion criteria were randomized controlled trials comparing the effectiveness of alectinib and crizotinib using an IHC-based companion diagnostic test. The primary outcome was progression-free survival (PFS). The secondary outcomes were objective response rate (ORR), duration of response (DOR), and overall survival (OS). PFS was longer in alectinib (68.4 [61.0, 75.9]) than crizotinib (48.7 [40.4, 56.9]). This indicated that alectinib had a superior efficacy to that of crizotinib (HR range 0.15–0.47). In all secondary outcomes, alectinib was better than crizotinib. Particularly for the ORR, the odds ratio (OR) confirmed that alectinib had a lower risk rate (OR: 2.21, [1.46–3.36], p = 0.0002, I² = 39%). Therefore, the companion diagnostic test (immunohistochemistry) is an effective test to determine whether to administer alectinib to ALK-positive NSCLC patients.

Molecular Diagnostics of Lung Cancer in Serous Effusion Samples

For molecular diagnostics of lung cancer samples, often only a small amount of material is available. The ever-increasing number of biomarker testing is in contrast to the amount of material obtained. In that case, cytological specimens, such as serous effusion samples, are one possible option. Effusion samples were prepared as sediment smears or cytospins or as a cell block if needed. Suitable tumor cells areas were marked by a cytopathologist and used for molecular diagnostics, including fast track analysis, parallel sequencing, and/or fluorescence in situ hybridization. In 62 cases of malignant effusion with cells of pulmonary adenocarcinoma, molecular diagnostics were carried out. A fast-track result with the high-resolution melting method for hotspot mutation of KRAS Exon 2 and EGFR exon 21 and fragment length analysis of EGFR exon 19 was available for 43 out of 47 samples (92%). Parallel sequencing was successful for 56 out of 60 samples (93.3%). In the same period, 108 FISH analyses were performed for MET amplification, followed by ROS1, RET, and ALK translocation analysis. If only a limited amount of tissue/biopsy is available, a malignant effusion is advisable to perform on the molecular diagnostics with a high success rate.

Molecular diagnosis in non-small-cell lung cancer: expert opinion on ALK and ROS1 testing

The effectiveness of targeted therapies with tyrosine kinase inhibitors in non-small-cell lung cancer (NSCLC) depends on the accurate determination of the genomic status of the tumour. For this reason, molecular analyses to detect genetic rearrangements in some genes (ie, ALK, ROS1, RET and NTRK) have become standard in patients with advanced disease. Since immunohistochemistry is easier to implement and interpret, it is normally used as the screening procedure, while fluorescence in situ hybridisation (FISH) is used to confirm the rearrangement and decide on ambiguous immunostainings. Although FISH is considered the most sensitive method for the detection of ALK and ROS1 rearrangements, the interpretation of results requires detailed guidelines. In this review, we discuss the various technologies available to evaluate ALK and ROS1 genomic rearrangements using these techniques. Other techniques such as real-time PCR and next-generation sequencing have been developed recently to evaluate ALK and ROS1 gene rearrangements, but some limitations prevent their full implementation in the clinical setting. Similarly, liquid biopsies have the potential to change the treatment of patients with advanced lung cancer, but further research is required before this technology can be applied in routine clinical practice. We discuss the technical requirements of laboratories in the light of quality assurance programmes. Finally, we review the recent updates made to the guidelines for the determination of molecular biomarkers in patients with NSCLC.

Traveling with ROSE in EBUS-TBNA - Experience from a Tertiary Care Hospital in South India

Aims and Objectives

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has emerged as a precise modality for tissue sampling of mediastinal and hilar lesions adjacent to the proximal airway. This study aims to determine the diagnostic efficacy, sensitivity, and specificity of rapid-on site evaluation (ROSE) in EBUS-TBNA.

Materials and Methods

This is a retrospective study that included 100 patients who underwent EBUS-TBNA of paratracheal and mediastinal lymph nodes in a tertiary care hospital in South India between March 2018 and March 2020. After the procedure, the diagnostic yield from the nodes sampled was transferred to slides that were stained with rapid hematoxylin and eosin (H and E), and then onsite evaluation was done. The tissue derived was also processed for histopathologic examination in all cases. ROSE was performed to assess sample adequacy and to arrive at a preliminary diagnosis. In patients suspected of tuberculosis, the sample was collected for GeneXpert evaluation as well.

Results

Of the 100 cases studied, 51 were males and 49 were females. The age distribution was between 3 and 78 years. Forty-seven cases were diagnosed as granulomatous lymphadenitis, 13 as metastatic malignancies, 33 as reactive lymphadenitis, 3 as atypical cells, and 1 case was diagnosed as a cystic lesion. The diagnostic yield was not adequate for evaluation in three cases. Diagnostic yield was obtained in the first two passes where the lymph nodes were more than 2 cm in size. More diagnostic passes were required in lymph nodes less than 2 cm and those located between and adjacent to major vessels. The onsite diagnosis was correlated with the final histopathologic diagnosis.

Conclusion

ROSE serves as a useful adjunct to reduce procedure time and enhance sample collection and triaging, and reduces the need for further invasive testing.

Molecular testing on serous effusion: An update

Cytological examination of the effusion fluid provides valuable information regarding the presence of malignancy. At times, it is challenging to diagnose malignant cells in serous effusion. The various ancillary techniques are available to solve the problem including immunocytochemistry, DNA ploidy, and multicolored flow cytometry. At present, the molecular tests on the effusion sample are of growing interest. The effusion sample is rich in cells and cell-free fluid that contains free DNA, cytokines, and extracellular vesicles. Molecular tests in effusion sample not only provide a diagnosis of malignancy but can also give valuable information that may be essential for the individualized therapy, management, and prognostic assessment. In this paper, we reviewed the application of the different molecular tests in the effusion sample.

The prevalence of tumour markers in malignant pleural effusions associated with primary pulmonary adenocarcinoma: a retrospective study

Background

Oncological treatment of primary pulmonary adenocarcinoma (AC) includes drugs targeting the pathways involving programmed death-ligand 1 (PD-L1), epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK). The aim of the study was to report the prevalence of these tumour markers in pleural fluid with cytology positive for pulmonary AC and the potential influence of volume pleural fluid tested.

Methods

We retrospectively reviewed all thoracenteses performed in a two-year period at our interventional unit at Department of Respiratory Medicine at Zealand University Hospital Naestved, Denmark. ALK and PD-L1 testing was done using immunohistochemistry and EGFR testing using next-generation sequencing. We included pleural fluid specimens containing malignant cells originating from primary pulmonary AC and with at least one tumour marker requested by the clinicians.

Results

When screening 927 pleural fluid specimens, we identified 57 in accordance with the inclusion criteria. PD-L1, ALK and EGFR were obtained in 35/55 (64%), 38/57 (67%) and 26/47 (55%), respectively. The prevalence did not increase when analysing volumes > 50 mL (p = 0.21–0.58)

Conclusion

Tumour markers in pleural fluid specimens containing cells from pulmonary AC can be demonstrated in more than half of the cases. Therefore, supplementary invasive procedures than thoracentesis could potentially await these analyses.

Cytologic Investigations for the Diagnosis of Malignant Pleural Effusion in Non-small Cell Lung Cancer: State-of-the-art Review for Pulmonologists

Lung cancer is the current leading cause of cancer-related deaths worldwide, and malignant pleural effusion, an indicator of the advanced stage of this disease, portends a poor prognosis. Thus, making an accurate diagnosis of malignant pleural effusion is of paramount importance. During the past decade, the prognosis of patients with advanced non-small cell lung cancer has improved substantially, especially in those treated with targeted therapy and immunotherapy. The use of pleural fluid cytology should not only provide diagnoses but also aid in the selection of targeted therapies, especially when obtaining a histologic specimen is too difficult. In this evidence-based review, we address the importance of pleural fluid cytology in non-small cell lung cancer patients, from making the diagnosis to making treatment-related decisions when only pleural fluid is available.

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.

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.

Cytology cell blocks from malignant pleural effusion are good candidates for PD-L1 detection in advanced NSCLC compared with matched histology samples

BACKGROUND

Detection of programmed cell death ligand-1 (PD-L1) by immunohistochemistry (IHC) has been commonly used to predict the efficacy of treatment with PD-1/PD-L1 inhibitors. However, there is limited literature regarding the reliability of PD-L1 testing using malignant pleural effusion (MPE) cell blocks. Here, we assess PD-L1 expression in sections from MPE cell blocks and evaluate the value of IHC double staining in the interpretation of PD-L1 expression.

METHODS

In all, 124 paired formalin-fixed tissues from advanced NSCLC patients, including MPE cell blocks and matched histology samples, were included. PD-L1 expression was assessed using the SP263 assay, and the tumor proportion score (TPS) and the staining intensity were evaluated. PD-L1 staining results were also compared between IHC double and single staining techniques.

RESULTS

PD-L1 expression was concordant in most paired cases (86/101, 85.1%) among three TPS cut-offs (<1%, 1-49% and ≥ 50%), with a kappa value of 0.774. Moreover, a significant difference in PD-L1 expression between MPE cell blocks and biopsy samples was observed (p = 0.005). For the 15 discordant pairs, 13 MPE cell block samples showed increased expression of PD-L1. Compared with the standard IHC single PD-L1 assay, double staining with anti-TTF-1 and anti-PD-L1 revealed a negative effect on PD-L1 expression testing and resulted in weaker staining intensity and a lower TPS (p = 0.000).

CONCLUSIONS

MPE cell block samples are good candidates for PD-L1 expression detection in advanced NSCLC patients. The mechanism and clinical significance of the higher PD-L1 expression rate in MPE cell blocks compared with small biopsy samples remain to be evaluated prospectively.

Processing and Reporting of Cytology Specimens from Mediastinal Lymph Nodes Collected using Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration: A State-of-the-Art Review

Endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) is presently the preferred modality for sampling mediastinal lymph nodes. There is an unmet need for standardization of processing and reporting of cytology specimens obtained by EBUS-TBNA. The manuscript is a state-of-the-art review on the technical aspects of processing and reporting of EBUS-TBNA specimens. A literature search was conducted using the PubMed database, and the available evidence was discussed among the authors. The evidence suggests that at least one air-dried and one alcohol-fixed slide should be prepared from each lymph node pass. The remaining material should be utilized for microbiological analysis (in saline) and cell block preparation (10% formalin or other solutions). Wherever available, rapid-onsite evaluation should be performed to assess the adequacy of the sample and guide the need for additional material. The lymph node aspirate should also be collected in Roswell Park Memorial Institute solution in cases where lymphoma is under consideration. The use of liquid-based cytology provides good quality specimens that are free from blood and air-drying artifacts and can be used wherever available. Sample adequacy and the diagnostic category should be furnished separately in the cytology report.

Current applications of molecular testing on body cavity fluids

INTRODUCTION

Effusion cytology has a high sensitivity for the diagnosis of malignancy and provides abundant material for molecular testing. Effusion draining is a minimally invasive procedure with few complications.

MATERIALS AND METHODS

We performed a review of publications regarding the use of molecular testing in serous effusions.

RESULTS

In diagnostics, BAP-1 IHC and CDKN2A FISH are powerful tools for the diagnosis of malignant mesothelioma. FISH, PCR, and EBER-ISH work well in lymphomas. RT-PCR may enhance the diagnosis of secondary epithelial malignancies. In theranostics, molecular testing on serous effusions is widely reported for the detection of alterations in genes related to lung carcinomas, such as EGFR, ALK, ROS1, and BRAF. PD-L1 expression testing by immunohistochemistry (IHC) also seems to be viable in this type of sample. HER2 FISH and IHC provide actionable results in the context of breast malignancies. Results in serous effusions seem to be equivalent to tissue biopsies for most applications and across different molecular techniques. The most interesting technology is next-generation sequencing (NGS), given its ability to sequence multiple genes on a single sample and the decreasing costs that have closely followed increasing throughputs. Cell-free DNA from effusion supernatants might be the most promising area for future research, showing superiority to serum and even to cell-block samples in limited studies.

CONCLUSIONS

Molecular tests are viable in serous effusion specimens when sufficient material is available. Given the rising importance of molecular testing we expect this to be an active field of research in the near future.

A technical review and guide to RNA fluorescence in situ hybridization

RNA-fluorescence in situ hybridization (FISH) is a powerful tool to visualize target messenger RNA transcripts in cultured cells, tissue sections or whole-mount preparations. As the technique has been developed over time, an ever-increasing number of divergent protocols have been published. There is now a broad selection of options available to facilitate proper tissue preparation, hybridization, and post-hybridization background removal to achieve optimal results. Here we review the technical aspects of RNA-FISH, examining the most common methods associated with different sample types including cytological preparations and whole-mounts. We discuss the application of commonly used reagents for tissue preparation, hybridization, and post-hybridization washing and provide explanations of the functional roles for each reagent. We also discuss the available probe types and necessary controls to accurately visualize gene expression. Finally, we review the most recent advances in FISH technology that facilitate both highly multiplexed experiments and signal amplification for individual targets. Taken together, this information will guide the methods development process for investigators that seek to perform FISH in organisms that lack documented or optimized protocols.

Proceedings of the American Society of Cytopathology companion session at the 2019 United States and Canadian Academy of Pathology Annual meeting, part 2: effusion cytology with focus on theranostics and diagnosis of malignant mesothelioma

We live in the "era" of minimally invasive procedures, molecular testing, and personalized care. Effusions have a high sensitivity and will often yield diagnostic cytological material. The companion session presented by the American Society of Cytopathology at the 2019 United States and Canadian Academy of Pathology meeting outlined our current and future projected practices in characterizing, managing, and diagnosing serous cavity fluids. In this second part, the role of theranostics and the diagnosis of malignant mesothelioma, as was discussed at the meeting, have been highlighted. In theranostics, a vast amount of data has been reported regarding the epidermal growth factor receptor and related molecules. Some studies have also reported on HER2 immunohistochemistry and fluorescence in situ hybridization. This follows the most active areas of research in targeted therapy. Furthermore, during this session, malignant mesothelioma was extensively discussed. The cytologic diagnosis of malignant mesothelioma in effusion specimens has been controversial; however, a definitive diagnosis will be possible in many cases. Radiologic information should be sought, because the radiologist can often provide a definite or very likely diagnosis of malignancy. Microscopically, high cellularity and/or numerous balls of cells or papillary groups will favor the diagnosis of mesothelioma. It is important to exclude metastatic carcinoma with a broad-spectrum carcinoma marker, of which claudin-4 has been the best, because it will not cross react with mesothelioma. BAP1 and MTAP immunohistochemistry and CDKN2A fluorescence in situ hybridization are very useful adjunctive techniques for separating benign from malignant mesothelial proliferations. The use of 2 of these approaches together will produce a sensitivity of 80% to 90% for epithelial mesotheliomas in the pleura, although the sensitivity has been lower in the peritoneal cavity.

ROS1-ADGRG6: a case report of a novel ROS1 oncogenic fusion variant in lung adenocarcinoma and the response to crizotinib

BACKGROUND

ROS1 rearrangements are validated drivers in lung cancer, which have been identified in a small subset (1-2%) of patients with non-small cell lung cancer (NSCLC). To date, 18 fusion genes of ROS1 have been identified in NSCLC. The ALK inhibitor (crizotinib) exhibits therapeutic effect against ROS1-rearranged NSCLC. Next-generation sequencing (NGS) technology represents a novel tool for ROS1 detection that covers many fusion genes.

CASE PRESENTATION

A 55-year-old female with EGFR mutation (L858R) was diagnosed with lung adenocarcinoma, who was responsive to first-generation EGFR-tyrosine kinase inhibitor (TKI). Afterwards, she developed acquired resistance accompanied with a ROS1 rearrangement. A NGS assay showed that the tumor had a novel ROS1-ADGRG6 rearrangement generated by the fusion of exons of 1-33 of ROS1 on chr6: q22.1 to exons of 2-26 of ADGRG6 on chr6: q24.2. The patient was obviously responsive to crizotinib.

CONCLUSION

We firstly identified ROS1-ADGRG6 fusion variant in NSCLC by NGS, which should be considered in further ROS1 detecting assays.

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.

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.

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.

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.

Benefit of crizotinib in a lung cancer patient with discordant ALK testing results

Crizotinib is a first line treatment for patients with non-small cell lung cancer (NSCLC) harboring translocations in anaplastic lymphoma kinase (ALK). The current gold standard for determining ALK status is fluorescence in-situ hybridisation (FISH), but immunohistochemistry (IHC) is becoming increasingly popular due to lower cost. There are currently few reports on clinical outcomes with crizotinib therapy in patients who have tested negative by FISH and positive by IHC. A 53 year old lifelong non-smoking, physically active male with newly diagnosed Stage IV NSCLC presented with shortness of breath on exertion one month prior to referral. Staging CT scan failed to show a discreet lung lesion, but the left lower lobe was collapsed due to pleural effusion. Pleural fluid showed adenocarcinoma and IHC was positive for an ALK mutation, while FISH was negative. Pre-treatment PET-CT showed hypermetabolic, enlarged lymph nodes in the mediastinum and retroperitoneum. Partially due to patient concerns about cytotoxic chemotherapy toxicity, crizotinib therapy was instituted. Repeat CT conducted two months after crizotinib initiation showed a decrease in lymphadenopathy at all sites compared to the PET-CT. Furthermore, the patient showed clinical improvement, with less drainage through his PleurX catheter and stability of his excellent performance status. After 12 months on crizotinib CT showed ongoing improvement in lymphadenopathy. His bloodwork has been stable, and he denies significant drug toxicity. This case illustrates a sustained response to crizotinib therapy in a patient with an ALK translocation identified by IHC, but with negative FISH testing. The literature suggests that the population with these discordant results could be up to 19% of ALK positive NSCLC. Patients in this subgroup who are receiving crizotinib should be identified and outcome data pooled. However, in the interim, oncologists may wish to consider targeted therapy for these discordant patients.

Discrepancies between ALK protein disruption and occurrence of ALK gene rearrangement in Polish NSCLC patients

BACKGROUND

Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK) rearrangement are predisposed to molecularly targeted therapies. Proper diagnostic is crucial for quick and correct patients qualification to optimal treatment method. Genetic tests to detect predictive factors could be performed sequentially. After excluding EGFR mutations, abnormal ALK protein expression should be tested using immunohistochemistry (IHC) method. In patients with disrupted ALK expression, the rearrangement of the ALK gene should be confirmed by FISH method. Despite few years of experience in analysis of these predictive factors, there are still problems in interpretation of diagnostic tests results. Especially, some recommendations for ALK IHC diagnosis are not precise.

METHODS

Mutations in EGFR gene were examined using real-time PCR technique in 1,108 formalin-fixed paraffin-embedded (FFPE) tissues, 398 FFPE cell-blocks and 470 cytological specimens of NSCLC. The disrupted ALK protein expression was analysed in 1,100 samples including 782 histological and 306 cytological (cell-blocks) samples using IHC. Twelve materials (1.1%) were non-diagnostic in IHC. ALK gene rearrangement using FISH method was analysed in IHC positive cases.

RESULTS

The frequency of EGFR mutations was 8.6%. EGFR mutations occurred significantly more often in females (P=0.00001, χ2=62.732) and in adenocarcinoma cases (P=0.0002, χ2=14.222). The exon 19 deletions (49%) and exon 21 Leu858Arg substitution (38%) were the most common, rare EGFR mutations occurred in 13% of patients. Any expression of abnormal ALK protein was detected in 202 cases (18.57%). ALK gene rearrangement was confirmed in 49 cases (4.5%). ALK gene rearrangement is significantly more common in female than in male (P=0.0105, χ2=6.541). In patients with ALK gene rearrangement, the median percentage of nuclei with ALK rearrangement was only 25.5%. The polysomy (≥4 gene copy number per nuclei) of ALK gene was observed in 39 cases (21.4% of patients with diagnostic result of FISH examination). Median number of ALK gene copy per nuclei was 2.9±0.77. Significant positive correlation between percentage of cells with abnormal ALK expression in IHC test and percentage of nuclei with ALK rearrangement in FISH method was detected (R=0.617, P<0.00001). Significant negative correlation between the number of copies of ALK gene and the percentage of cells with expression of abnormal ALK was observed (R=-0.2004, P<0.05). ALK gene rearrangement was significantly more frequently observed in the material with coarse-grained cytoplasmic and membranous IHC staining than in materials with light cytoplasmic stippling. The occurrence of cytoplasmic stippling correlated with the increase of ALK gene copy number.

CONCLUSIONS

We indicated that diagnosis of ALK disruption in NSCLC patients should be notably careful using IHC and FISH methods. Recommendations for ALK diagnosis should include the way of interpretation of cases with low percentage of cells with abnormal ALK protein expression in IHC test, character of IHC reaction, and cases with ALK gene polysomy in FISH method.

Telomere length determined by the fluorescence in situ hybridisation distinguishes malignant and benign cells in cytological specimens

BACKGROUND

Telomeres are tandem repeats of TTAGGG at the end of eukaryotic chromosomes that play a key role in preventing chromosomal instability. The aim of the present study is to determine telomere length using fluorescence in situ hybridisation (FISH) on cytological specimens.

METHODS

Aspiration samples (n = 41) were smeared on glass slides and used for FISH.

RESULTS

Telomere signal intensity was significantly lower in positive cases (cases with malignancy, n = 25) as compared to negative cases (cases without malignancy, n = 16), and the same was observed for centromere intensity. The difference in DAPI intensity was not statistically significant. The ratio of telomere to centromere intensity did not show a significant difference between positive and negative cases. There was no statistical difference in the signal intensities of aspiration samples from ascites or pleural effusion (n = 23) and endoscopic ultrasound-guided FNA samples from the pancreas (n = 18).

CONCLUSIONS

The present study revealed that telomere length can be used as an indicator to distinguish malignant and benign cells in cytological specimens. This novel approach may help improve diagnosis for cancer patients.

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.

CEP72-ROS1: A novel ROS1 oncogenic fusion variant in lung adenocarcinoma identified by next-generation sequencing

ROS1 rearrangement is a validated therapeutic driver gene in non‐small cell lung cancer (NSCLC) and represents a small subset (1–2%) of NSCLC. A total of 17 different fusion partner genes of ROS1 in NSCLC have been reported. The multi‐targeted MET/ALK/ROS1 tyrosine kinase inhibitor (TKI) crizotinib has demonstrated remarkable efficacy in ROS1‐rearranged NSCLC. Consequently, ROS1 detection assays include fluorescence in situ hybridization, immunohistochemistry, and real‐time PCR. Next‐generation sequencing (NGS) assay covers a range of fusion genes and approaches to discover novel receptor‐kinase rearrangements in lung cancer. A 63‐year‐old male smoker with stage IV NSCLC (TxNxM1) was detected with a novel ROS1 fusion. Histological examination of the tumor showed lung adenocarcinoma. NGS analysis of the hydrothorax cellblocks revealed a novel CEP72‐ROS1 rearrangement. This novel CEP72‐ROS1 fusion variant is generated by the fusion of exons 1–11 of CEP72 on chromosome 5p15 to exons 23–43 of ROS1 on chromosome 6q22. The predicted CEP72‐ROS1 protein product contains 1202 amino acids comprising the N‐terminal amino acids 594–647 of CEP72 and C‐terminal amino acid 1‐1148 of ROS1. CEP72‐ROS1 is a novel ROS1 fusion variant in NSCLC discovered by NGS and could be included in ROS1 detection assay, such as reverse transcription PCR. Pleural effusion samples show good diagnostic performance in clinical practice.

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.

Responses to crizotinib in patients with ALK-positive lung adenocarcinoma who tested immunohistochemistry (IHC)-positive and fluorescence in situ hybridization (FISH)-negative

Although the Ventana immunohistochemistry (IHC) platform for detecting anaplastic lymphoma kinase gene (ALK) (D5F3) expression was recently approved by the US Food and Drugs Administration (FDA), fluorescence in situ hybridization (FISH) is still the "gold-standard" method recommended by the US National Comprehensive Cancer Network (NCCN) guideline for NSCLC. We evaluated 6 ALK-positive lung adenocarcinoma patients who tested Ventana IHC-positive and FISH-negative and assessed their clinical responses to the ALK tyrosine kinase inhibitor (TKI) crizotinib. Histologic and cytologic specimens from the 6 patients were stained with Ventana anti-ALK(D5F3) rabbit monoclonal primary antibody using the OptiView™ DAB IHC detection kit and OptiView™ amplification kit on a Ventana BenchMark XT processor. In addition, they were also tested by FISH, qRT-PCR, next-generation sequencing (NGS), and RNAscope ISH analysis. All patients received crizotinib treatment and their follow-up clinical data were recorded. The objective response rate achieved with crizotinib therapy was 66.7% (4/6 partial responses and 2/6 stable disease). One patient in whom a new fusion type (EML4->EXOC6B->ALK fusion) was identified obtained a partial response. These findings indicate that patients with ALK-positive lung adenocarcinoma who test Ventana IHC-positive and FISH-negative may still respond to crizotinib therapy.

Analysis of Fusion Genes by NanoString System: A Role in Lung Cytology?

CONTEXT

- Patients with non-small cell lung cancer harboring ALK receptor tyrosine kinase ( ALK), ROS proto-oncogene 1 ( ROS1), and ret proto-oncogene ( RET) gene rearrangements can benefit from specific kinase inhibitors. Detection of fusion genes is critical for determining the best treatment. Assessing rearrangements in non-small cell lung cancer remains challenging, particularly for lung cytology.

OBJECTIVE

- To examine the possible application of the multiplex, transcript-based NanoString system (NanoString Technologies, Seattle, Washington) in the evaluation of fusion genes in lung adenocarcinoma samples.

DATA SOURCES

- This study is a narrative literature review. Studies about NanoString, gene fusions, and lung adenocarcinoma were collected from PubMed (National Center for Biotechnology Information, Bethesda, Maryland). We found 7 articles about the application of the NanoString system to detect fusion genes on formalin-fixed, paraffin-embedded tumor tissues and one article evaluating the adequacy of lung cytologic specimens for NanoString gene expression analysis.

CONCLUSIONS

- To maximize the yield of molecular tests on small lung biopsies, the NanoString nCounter system has been suggested to detect fusion genes. NanoString fusion gene assays have been successfully applied on formalin-fixed, paraffin-embedded tissues. Although there are only a few studies available, the application of NanoString assays may also be feasible in lung cytology. According to available data, the NanoString system could strengthen the routine molecular characterization of lung adenocarcinoma.

Comparison of ALK status between primary and corresponding lymph node metastatic tumors in lung cancer patients

Background

The anaplastic lymphoma kinase (ALK) protein has recently become a promising target in the treatment of non-small cell lung carcinomas(NSCLC) patients with ALK translocation because of the high response rates obtained with an ALK inhibitor. ALK translocations are present in approximately 3-5% of NSCLC patients. According to the literature, little information about the relationship of ALK status between the primary tumor and metastatic sites has been reported. We intended to determine whether the ALK translocations of primary lung cancers are consistent with those in corresponding metastatic lymph node tumors.

Materials and Methods

We analyzed ALK translocations from paired primary and metastatic lymph node tumors in 78 lung cancer patients who had not received TKI before the tissues were sampled.

Results

Using fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) methods, all 45 patients with ALK translocation-positive primary lung tumors had translocations in the metastases. For 33 patients who were ALK negative in the primary tumors, 1 (3%) was ALK positive in their metastatic tumors.

Conclusion

According to a paired t-test, there is no significant difference between primary lung tumors and metastatic sites. Analysis of ALK translocations in the primary lung tumor would be suitable for planning the use of a TKI for advanced NSCLC, but it would be better to detect metastasis specimens as ALK negative specimens if both primary and metastatic specimens have developed.

A comparative study of conventional cytology and cell block method in the diagnosis of pleural effusion

Background

In a patient with pleural effusion, cytological study (CS) is one of the most useful investigations, especially when malignancy is suspected. Instead of applying only CS, the pleural fluid can be further processed using the cell block (CB) technique, which may augment the diagnostic utility. The aim of this study was to compare the diagnostic yields of CS, CB, and the combination of both, regardless of the etiology of pleural effusion.

Methods

A cross-sectional study was conducted on patients with pleural effusions who underwent thoracentesis from June 2015 to May 2016. All samples were submitted for routine biochemical analysis, CS, and CB histology. The results of cytopathological studies were compared to the final diagnoses.

Results

Out of a total of 353 samples, the final diagnoses included 278 (78.8%) malignancies, 41 (11.6%) infectious diseases, 16 (4.5%) other inflammatory diseases, and 18 (5.1%) transudative pleural effusions. CS and CB provided a similar diagnostic yield (48.7% vs. 49.9%, P=0.69), while the combination of both gave a higher yield (57.2%) (P<0.001, compared with CS). Among 278 malignant pleural effusions (MPE), the diagnostic yields of CS and CB were 61.2% and 61.9%, respectively. Combined CS and CB improved the diagnostic yield to 71.2% (P<0.001). However, both CS and CB had low diagnostic yields in infectious pleuritis, other inflammatory diseases, and transudative pleural effusions.

Conclusions

In MPE, CB provides a similar diagnostic performance to CS, while application of both techniques can significantly increase the diagnostic yield. However, in other pleural diseases, CB and CS had limited values in diagnosis.

Ventana immunohistochemistry assay for anaplastic lymphoma kinase gene rearrangement detection in patients with non-small cell lung cancer: A meta-analysis

Background

The aim of this study was to evaluate the diagnostic value of Ventana immunohistochemistry (IHC) assay for anaplastic lymphoma kinase (ALK) gene rearrangement screening in patients with non‐small cell lung cancer (NSCLC).

Methods

Open published studies that reported the diagnostic performance of Ventana IHC assay for ALK gene rearrangement detection in NSCLC patients were extracted from PubMed, Embase, Google scholar, Wanfang, and China National Knowledge Infrastructure. The general information and number of true positive (tp), false positive (fp), false negative (fn), and true negative (tn) cases identified by Ventana IHC assay were extracted. The diagnostic sensitivity, specificity, positive likelihood ratio (+lr), negative likelihood ratio (−lr), diagnostic odds ratio (dor) and the summary receiver operating characteristic (ROC) curve were calculated using Stata 11.0 software.

Results

Ten studies, including 240 ALK positive and 1973 ALK negative NSCLC patients were included in this meta‐analysis. The pooled diagnostic sensitivity, specificity, +lr, −lr, and dor were 0.94 (95% confidence interval [CI] 0.85–0.98), 1.00 (95% CI 0.99–1.00), 859.61 (95% CI 60.81–1200.00), 0.06 (95% CI 0.03–0.16), and 1400.00 (95% CI 813.29–23 000.00), respectively. The area under the ROC curve was 0.996 for Ventana IHC assay in detecting ALK gene rearrangement in NSCLC patients.

Conclusion

The sensitivity and specificity of Ventana IHC assay for the detection of ALK gene rearrangement were high, thus Ventana IHC could substitute fluorescence in situ hybridization for the screening of ALK+ NSCLC patients.

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.

Responses to Crizotinib therapy in five patients with non-small-cell lung cancer who tested FISH negative and Ventana immunohistochemistry positive for ALK fusions

AIM

Although immunohistochemistry (IHC) and reverse transcription-PCR can detect ALK rearrangements, the ALK break-apart FISH assay is currently considered the standard method.

MATERIALS & METHODS

Five patients with advanced non-small-cell lung cancer, who had an ALK-negative FISH result that was later confirmed as positive by the Ventana IHC assay, were studied. Four had previously received chemotherapy or radiotherapy. All five were subsequently treated with Crizoitinib 250 mg twice daily.

RESULTS & CONCLUSION

Four patients had a partial response to Crizotinib and one had stable disease. IHC is an efficient technique for diagnosing ALK rearrangements in patients with non-small-cell lung cancer, and may serve as an alternative to FISH in clinical practice.

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.

Assessment of cytology based molecular analysis to guide targeted therapy in advanced non-small-cell lung cancer

To investigate the use of molecular testing on cytological specimens in selecting advanced non-small cell lung cancer (NSCLC) patients who are adequate for targeted treatment, a total of 137 NSCLC cases were analyzed by fluorescence in situ hybridization (FISH) for anaplastic lymphoma kinase (ALK) rearrangements, and Epidermal growth factor receptor (EGFR), kirsten rat sarcoma viral oncogene homolog (KRAS) mutations were evaluated by quantitative real-time PCR (qRT-PCR) platform combining amplification refractory mutation system (ARMS) primers and TaqMan probes. Cytological specimens included 91 fine-needle aspirates, 5 fibreoptic bronchoscopic derived samples and 41 pleural effusions. Among 137 NSCLCs analyzed for ALK FISH, 16 (11.7%, of 137) were detected to harbor ALK rearrangement. FISH positive cases were all defined as adenocarcinoma (ADC) histologic subtype and the FNA samples showed the highest ALK positive rate (13.2%, 12/91). Of the 9 ALK FISH positive patients who received crizotinib treatment, 8 (88.9%) patients exhibited tumor regression. In addition, 60 (44.8%, of 134) cases were found to harbor EGFR mutations and 22 patients with EGFR sensitive mutations who received gefitinib or erlotinib treatment showed a median PFS of 16.0 months. Mutations of KRAS occurred in 8 (6.0%, of 134) cases and this was mutually exclusive from EGFR mutation. Our results demonstrated that ALK FISH and EGFR, KRAS mutational analysis on cytological specimens are sensitive methods for screening advanced stage NSCLC patients who are adequate for targeted treatment.

Diagnostic Utility of Pleural Fluid Cell Block versus Pleural Biopsy Collected by Flex-Rigid Pleuroscopy for Malignant Pleural Disease: A Single Center Retrospective Analysis

Background

Some trials recently demonstrated the benefit of targeted treatment for malignant disease; therefore, adequate tissues are needed to detect the targeted gene. Pleural biopsy using flex-rigid pleuroscopy and pleural effusion cell block analysis are both useful for diagnosis of malignancy and obtaining adequate samples. The purpose of our study was to compare the diagnostic utility between the two methods among patients with malignant pleural disease with effusion.

Methods

Data from patients who underwent flex-rigid pleuroscopy for diagnosis of pleural effusion suspicious for malignancy at the National Cancer Center Hospital, Japan between April 2011 and June 2014 were retrospectively reviewed. All procedures were performed under local anesthesia. At least 150 mL of pleural fluid was collected by pleuroscopy, followed by pleural biopsies from the abnormal site.

Results

Thirty-five patients who were finally diagnosed as malignant pleural disease were included in this study. Final diagnoses of malignancy were 24 adenocarcinoma, 1 combined adeno-small cell carcinoma, and 7 malignant pleural mesothelioma (MPM), and 3 metastatic breast cancer. The diagnostic yield was significantly higher by pleural biopsy than by cell block [94.2% (33/35) vs. 71.4% (25/35); p = 0.008]. All patients with positive results on cell block also had positive results on pleural biopsy. Eight patients with negative results on cell block had positive results on pleural biopsy (lung adenocarcinoma in 4, sarcomatoid MPM in 3, and metastatic breast cancer in 1). Two patients with negative results on both cell block and pleural biopsy were diagnosed was sarcomatoid MPM by computed tomography-guided needle biopsy and epithelioid MPM by autopsy.

Conclusion

Pleural biopsy using flex-rigid pleuroscopy was efficient in the diagnosis of malignant pleural diseases. Flex-rigid pleuroscopy with pleural biopsy and pleural effusion cell block analysis should be considered as the initial diagnostic approach for malignant pleural diseases presenting with effusion.

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.

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.

Malignant pleural effusion cell blocks are substitutes for tissue in EML4-ALK rearrangement detection in patients with advanced non-small-cell lung cancer

OBJECTIVE

To evaluate the feasibility of malignant pleural effusions (MPE) as surrogate samples for the detection of echinoderm microtubule-associated protein-like4 (EML4)-anaplastic lymphoma kinase (ALK) and to investigate the prognostic and predictive value of EML4-ALK in MPE of non-small-cell lung cancer (NSCLC).

METHODS

One hundred and nine NSCLC patients were retrospectively analysed. EML4-ALK was identified using paraffin-embedded tumour cells in MPE samples by immunohistochemistry (IHC, Ventana) and confirmed by fluorescence using in situ hybridisation (FISH) and qRT-PCR. The EGFR mutation was determined by MPE, using denaturing high-performance liquid chromatography (DHPLC).

RESULTS

A total of 5 out of 109 (4.58%) patients were identified as EML4-ALK rearrangement in MPE by IHC.; In addition to two metachronous samples, the consistency of MPE and tissue for EML4-ALK detection was 100% (21/21), and the sensitivity and specificity were 100% (2/2) and 100% (19/19), respectively. EML4-ALK rearrangement cases were confirmed by FISH and qRT-PCR; the sensitivity were both 100% (2/2) when compared with tissue, and it was 60% (3/5) and 100% (5/5), respectively, when compared with MPE by IHC. The overall response rate (ORR) was 100% (2/2) for patients with EML4-ALK in MPE. Moreover, the PFS of these patients appeared to be prolonged in chemotherapy (9.27 versus 6.53 and versus 4.67 months, P = 0.122), compared with the EGFR mutation and the EGFR/ALK double negative group, respectively.

CONCLUSION

EML4-ALK rearrangement detection in malignant pleural effusions is a complementary method for EML4-ALK detection. VETANA and qRT-PCR are more appropriate for MPE detection. EML4-ALK rearrangement in pleural effusions has a predictive value for treatment.

Feasibility of cytological specimens for ALK fusion detection in patients with advanced NSCLC using the method of RT-PCR

OBJECTIVES

Histological tissues are preferred for anaplastic lymphoma kinase (ALK) fusion detection in non-small cell lung cancer (NSCLC). The aim of this study was to evaluate the feasibility of cytological sample as an alternative specimen for ALK fusion testing in patients with advanced NSCLC.

MATERIALS AND METHODS

Advanced NSCLC patients with cytological specimens or tumor tissue who had their ALK fusion status detected by the method of reverse transcriptase polymerase chain reaction (RT-PCR) in Shanghai Pulmonary Hospital, Tongji University were included into this study. The efficacy was evaluated in those with ALK fusion positive and received the therapy of crizotinib.

RESULTS

1274 patients were included in this study. Among them, 108 patients were ALK RT-PCR positive and 69 of them received crizotinib treatment. Among 1002 patients with cytological specimens, the average concentration of RNA extracted from cytological specimens was 60.99 ng/μl (95% confidence interval [CI], 55.56-66.60) and the incidence rate of ALK fusion was 8.3% (83/1002), which were similar to 63.16 ng/μl (95% CI, 51.88-76.34) (p=0.727) and 9.2% (25/272, p=0.624) in 272 patients with tumor tissue. Also, there were no statistically significant differences regarding to the objective response rate (ORR) (62.0% vs. 42.1%, p=0.177) and the median progression free survival (mPFS) [8.6 months (95% CI 7.30-9.84) vs. 7.0 months (95% CI 4.54-9.47), p=0.736] in patients of cytological group and tissue group after the treatment of crizotinib.

CONCLUSION

Cytological specimens showed a high feasibility to detect ALK fusion status, which could be regarded as alternative samples for ALK fusion detection by the method of RT-PCR in patients with advanced NSCLC.

ALK gene expression status in pleural effusion predicts tumor responsiveness to crizotinib in Chinese patients with lung adenocarcinoma

Objective

The relationship between anaplastic lymphoma kinase (ALK) expression in malignant pleural effusion (MPE) samples detected only by Ventana immunohistochemistry (IHC) ALK (D5F3) and the efficacy of ALK-tyrosine kinase inhibitor therapy is uncertain.

Methods

Ventana anti-ALK (D5F3) rabbit monoclonal primary antibody testing was performed on 313 cell blocks of MPE samples from Chinese patients with advanced lung adenocarcinoma, and fluorescence in situ hybridization (FISH) was used to verify the ALK gene status in Ventana IHC ALK (D5F3)-positive samples. The follow-up clinical data on patients who received crizotinib treatment were recorded.

Results

Of the 313 MPE samples, 27 (8.6%) were confirmed as ALK expression-positive, and the Ventana IHC ALK (D5F3)-positive rate was 17.3% (27/156) in wild-type epidermal growth factor receptor (EGFR) MPE samples. Twenty-three of the 27 IHC ALK (D5F3)-positive samples were positive by FISH. Of the 11 Ventana IHC ALK (D5F3)-positive patients who received crizotinib therapy, 2 patients had complete response (CR), 5 had partial response (PR) and 3 had stable disease (SD).

Conclusions

The ALK gene expression status detected by the Ventana IHC ALK (D5F3) platform in MPE samples may predict tumor responsiveness to crizotinib in Chinese patients with advanced lung adenocarcinoma.