Suitability of thoracic cytology for new therapeutic paradigms in non-small cell lung carcinoma: high accuracy of tumor subtyping and feasibility of EGFR and KRAS molecular testing

Cytomorphological Features as a Subtyping Tool of Non-Small-Cell Lung Cancer in Brushing Bronchoscopic Samples

Background and Objective

Nowadays, the separation of adenocarcinomas (ADCs) and squamous cell carcinomas (SCCs) is crucial given that there are new specific targeted therapies. So, the aim of this study was to examine the differences in cytomorphological features between ADC and SCC in bronchoscopic brush samples.

Material and Methods

The retrospective study was conducted over a 3-year period at Western Balkan University Hospital. All brushing samples were analysed. According to the histopathological report, patients were classified into ADC and SCC groups. The cytomorphological features analysed in 95 samples were presence of necrosis, cell distribution, nuclear atypia, size of nuclei, and visibility of nucleoli. Statistical analysis was performed in JASP, and P values <0.05 were considered significant.

Results

The necrotic background was more frequent in SCC samples. Small clusters sized ≤200 µm were found in 17.95% of samples from the SCC group and 53.57% in the ADC group. Large clusters sized >400 µm were found in 43.59% in the SCC group, while in the ADC group, it was found in 5.36%. There were no differences in nuclear atypia between groups. Nuclei that were >5x lymphocyte size were found more often in samples from ADC than in the SCC group (37.50 vs 10.25%). In 89.75% of samples from the SCC group, nuclei were ≤5x lymphocyte sizes, while in the ADC group, the percentage was 63.5%. Nucleoli were more often visible in samples from the ADC group compared to the SCC group (92.86% vs 64.10%, P < 0,05).

Conclusions

Small clusters, large nuclei, and visible nucleoli were more frequent in the ADC group (P < 0.05), while large clusters, small nuclei, and invisible nucleoli were more frequent in the SCC group (P < 0.05).

Retrospective application of WHO reporting system for lung cytopathology with assessment of risk of malignancy

INTRODUCTION

The recently introduced World Health Organization (WHO) Reporting System for Lung Cytopathology presents 5 diagnostic categories with corresponding risk of malignancy (ROM) and management protocols. This study uses the system to categorize our institutional respiratory tract cytology specimens, evaluating ROM and diagnostic accuracy for each category.

MATERIALS AND METHODS

In a retrospective analysis (May 2020 to August 2021), the following respiratory cytology specimens were classified based on the WHO categories: bronchoalveolar lavage (BAL), bronchial wash/bronchial brushings (BB/BW), endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), fine-needle aspiration cytology (FNAC), sputum, biopsy imprint (BI), and endotracheal wash. Exclusions comprised pleural effusions and EBUS-TBNA from mediastinal and hilar lymph nodes. Correlation of cytologic and histopathologic diagnoses was performed to assess ROM collectively and individually.

RESULTS

A total of 1518 respiratory samples (BAL [968], BW/BB [380], EBUS-TBNA [42], FNAC [32], sputum [80], BI [11] and endotracheal wash [5]) of 1410 patients were screened, of which 522 cases (34.3%) had histopathologic correlation. One hundred forty-one cases (9.3%) were Insufficient/Inadequate/Non-Diagnostic (ND), 1221 (80.4%) were Benign (B), 3 (0.2%) were Atypical (A), 32 (2.1%) were Suspicious for malignancy (SM) and 121 (8.0%) were Malignant (M). The estimated ROM for each category was 49.2% for ND, 13.3% for B, 66.6% for A, 81.5% for SM and 92.7% for M. FNAC and EBUS-TBNA exhibited the highest sensitivity (100%) compared with BW/BB (66.3%). Specificity ranged from 96.8% to 100% across the samples, while diagnostic accuracy varied from 58.8% to 100%.

CONCLUSIONS

Application of the WHO reporting system enhances standardized terminology, aiding clinicians in informed decision-making and improving patient care through accurate risk assessment of malignancy.

"SMART" cytology: The next generation cytology for precision diagnosis

Cytology plays an important role in diagnosing and managing human diseases, especially cancer, as it is often a simple, low cost yet effective, and non-invasive or minimally invasive diagnostic tool. However, traditional morphology-based cytology practice has limitations, especially in the era of precision diagnosis. Recently there have been tremendous efforts devoted to apply computational tools and to perform molecular analysis on cytological samples for a variety of clinical purposes. Now is probably the appropriate juncture to integrate morphology, machine learning, and molecular analysis together and transform cytology from a morphology-driven practice to the next level - "SMART" Cytology. In this article we will provide a rather brief review of the relevant works for computational analysis on cytology samples, focusing on single-cell-based multiplex quantitative analysis of biomarkers, and introduce the conceptual framework of "SMART (Single cell, Multiplex, AI-driven, and Real Time)" Cytology.

Cytological Samples: An Asset for the Diagnosis and Therapeutic Management of Patients with Lung Cancer

BACKGROUND

Lung cancer has become the leading cause of cancer death for men and women. Most patients are diagnosed at an advanced stage when surgery is no longer a therapeutic option. At this stage, cytological samples are often the less invasive source for diagnosis and the determination of predictive markers. We assessed the ability of cytological samples to perform diagnosis, and to establish molecular profile and PD-L1 expression, which are essential for the therapeutic management of patients.

METHODS

We included 259 cytological samples with suspected tumor cells and assessed the ability to confirm the type of malignancy by immunocytochemistry. We summarized results of molecular testing by next generation sequencing (NGS) and PD-L1 expression from these samples. Finally, we analyzed the impact of these results in the patient management.

RESULTS

Among the 259 cytological samples, 189 concerned lung cancers. Of these, immunocytochemistry confirmed the diagnosis in 95%. Molecular testing by NGS was obtained in 93% of lung adenocarcinomas and non-small cell lung cancer. PD-L1 results were obtained in 75% of patients tested. The results obtained with cytological samples led to a therapeutic decision in 87% of patients.

CONCLUSION

Cytological samples are obtained by minimally invasive procedures and can provide enough material for the diagnosis and therapeutic management in lung cancer patients.

Prediction of high-grade patterns of stage IA lung invasive adenocarcinoma based on high-resolution CT features: a bicentric study

OBJECTIVES

This study aims to predict the high-grade pattern (HGP) of stage IA lung invasive adenocarcinoma (IAC) based on the high-resolution CT (HRCT) features.

METHODS

The clinical, pathological, and HRCT imaging data of 457 patients (from bicentric) with pathologically confirmed stage IA IAC (459 lesions in total) were retrospectively analyzed. The 459 lesions were classified into high-grade pattern (HGP) (n = 101) and non-high-grade pattern (n-HGP) (n = 358) groups depending on the presence of HGP (micropapillary and solid) in pathological results. The clinical and pathological data contained age, gender, smoking history, tumor stage, pathological type, and presence or absence of tumor spread through air spaces (STAS). CT features consisted of lesion location, size, density, shape, spiculation, lobulation, vacuole, air bronchogram, and pleural indentation. The independent predictors for HGP were screened by univariable and multivariable logistic regression analyses. The clinical, CT, and clinical-CT models were constructed according to the multivariable analysis results.

RESULTS

The multivariate analysis suggested the independent predictors of HGP, encompassing tumor size (p = 0.001; OR = 1.090, 95% CI 1.035-1.148), density (p < 0.001; OR = 9.454, 95% CI 4.911-18.199), and lobulation (p = 0.002; OR = 2.722, 95% CI 1.438-5.154). The AUC values of clinical, CT, and clinical-CT models for predicting HGP were 0.641 (95% CI 0.583-0.699) (sensitivity = 69.3%, specificity = 79.2%), 0.851 (95% CI 0.806-0.896) (sensitivity = 79.2%, specificity = 79.6%), and 0.852 (95% CI 0.808-0.896) (sensitivity = 74.3%, specificity = 85.8%).

CONCLUSION

The logistic regression model based on HRCT features has a good diagnostic performance for the high-grade pattern of stage IA IAC.

KEY POINTS

• The AUC values of clinical, CT, and clinical-CT models for predicting high-grade patterns were 0.641 (95% CI 0.583-0.699), 0.851 (95% CI 0.806-0.896), and 0.852 (95% CI 0.808-0.896). • Tumor size, density, and lobulation were independent predictive markers for high-grade patterns. • The logistic regression model based on HRCT features has a good diagnostic performance for the high-grade patterns of invasive adenocarcinoma.

Non-small cell lung carcinoma subtyping in conventional cytology: Results of the IASLC Cytology Working Group survey to determine specific cytomorphological criteria for adenocarcinoma and squamous cell carcinoma

INTRODUCTION

Accurate subtyping of non-small cell lung carcinomas (NSCLC) into lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) is the cornerstone of NSCLC diagnosis. Cytology samples show higher rates of classification failures, i.e., subtyping as non-small cell carcinoma, not otherwise specified (NSCC-NOS), as compared to histology. This study aims to identify specific algorithms based on known cytomorphological features that aid accurate and successful subtyping of NSCLC on cytology.

METHODS

Thirteen expert cytopathologists participated anonymously in an online survey to subtype 119 NSCLC cytology cases (gold standard diagnoses being LUAD in 80 and LUSC in 39) enriched for non-keratinising LUSC. They selected from 23 pre-defined cytomorphological features that they used in subtyping. Data were analysed using machine learning algorithms based on Random Forest Method and regression trees.

RESULTS

From 1474 responses recorded, concordant cytology typing was achieved in 53.7% (792/1474) responses. NSCC-NOS rates on cytology were similar among gold standard LUAD (36%) and LUSC (38%) cases. Misclassification rates were higher in gold standard LUSC (17.6%) than gold standard LUAD (5.5%; P<0.0001). Keratinisation, when present, recognised LUSC with high accuracy. In its absence, the ML algorithms developed based on experts' choices were unable to reduce cytology NSCC-NOS rates without increasing misclassification rates.

CONCLUSION

Suboptimal recognition of LUSC in the absence of keratinisation remains the major hurdle in improving cytology subtyping accuracy with such cases either failing classification (NSCC-NOS) or misclassifying as LUAD. NSCC-NOS appears to be an inevitable morphological diagnosis emphasizing that ancillary IC is necessary to achieve accurate subtyping on cytology.

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.

CT-Guided Transthoracic Biopsy of Pulmonary Lesions: Diagnostic versus Nondiagnostic Results

(1) Background: Despite the high accuracy of CT-guided transthoracic biopsy for diagnosis of pulmonary lesions, in a certain amount of cases biopsy results may indicate the presence of nonspecific findings or insufficient material. We aimed to investigate the effectiveness of CT-guided transthoracic biopsy of pulmonary lesions in providing a specific diagnosis and to analyze the variables affecting biopsy results. (2) Methods: In this retrospective study, a total of 170 patients undergoing 183 CT-guided transthoracic biopsies of pulmonary lesions were included. The clinical, radiological and pathological data were reviewed to classify biopsy results as diagnostic or nondiagnostic and to identify which variables were associated with the two groups. (3) Results: The biopsy results were diagnostic in 150 cases (82.0%), of which 131 (87.3%) positive for malignancy and 19 (12.7%) with specific benign lesions, and nondiagnostic in 33 cases (18.0%). Twenty-two of the thirty-three (66.7%) nondiagnostic cases were finally determined as malignancies and eleven (33.3%) as benign lesions. In the diagnostic group, all the 131 biopsies positive for malignancy were confirmed to be malignant at final diagnosis (87.3%); of 19 biopsies with specific benign lesions, 13 cases were confirmed to be benign (8.7%), whereas six cases had a final diagnosis of malignancy (4%). Multivariate analysis showed increased risk of nondiagnostic biopsy for lesions ≤ 20 mm (p = 0.006) and lesions with final diagnosis of benignity (p = 0.001). (4) Conclusions: CT-guided transthoracic lung biopsy is an effective technique for the specific diagnosis of pulmonary lesions, with a relatively acceptable proportion of nondiagnostic cases. Small lesion size and final benign diagnosis are risk factors for nondiagnostic biopsy results.

[Role and Significance of Bioactive Substances in Sputum in the Diagnosis of Lung Cancer]

肺癌是我国目前发病率最高的恶性肿瘤之一，其诊断的金标准需要进行组织活检的病理学检查或脱落细胞学检查，二者的有创性和敏感性限制了他们的使用。痰液中含有大量核酸、蛋白质，是肺功能的良好反映物，肺癌组织也会影响痰液中的生物成分，检测其中的生物活性物质可有助于肺癌的诊断。本文综合目前国内外的研究结果，对痰液中可用于肺癌诊断的生物活性物质做一综述。

The 2021 WHO Classification of Lung Tumors: Impact of advances since 2015

The 2021 World Health Organisation (WHO) Classification of Thoracic Tumours was published earlier this year, with classification of lung tumors being one of the chapters. The principles remain those of using morphology first, supported by immunohistochemistry and then molecular techniques. In 2015, there was particular emphasis on using immunohistochemistry to make classification more accurate. In 2021, there is greater emphasis throughout the book on advances in molecular pathology across all tumor types. Major features within this edition are 1) broader emphasis on genetic testing than in the 2015 WHO Classification, 2) a chapter entirely dedicated to the classification of small diagnostic samples, 3) continued recommendation to document percentages of histological patterns in invasive non-mucinous adenocarcinomas, with utilization of these features to apply a formal grading system, as well as using only invasive size for T-factor size determination in part lepidic non-mucinous lung adenocarcinomas as recommended by the 8^th Edition TNM Classification, 4) recognition of spread through airspaces (STAS) as a histological feature with prognostic significance, 5) moving lymphoepithelial carcinoma to squamous cell carcinomas, 6) update on evolving concepts in lung neuroendocrine neoplasm classification, 7) recognition of bronchiolar adenoma/ciliated muconodular papillary tumor (BA/CMPT) as a new entity within the adenoma subgroup, 8) recognition of thoracic SMARCA4-deficient undifferentiated tumor, and 9) inclusion of essential and desirable diagnostic criteria for each tumor.

Can cytology reliably subtype non-small cell lung carcinomas?

Cytology specimens play an important role in the diagnosis and predictive testing of lung cancer. While morphological characterisation of small cell and non-small cell lung carcinomas (NSCLC) on cytology is possible, further subtyping of NSCLC into adenocarcinoma and squamous cell carcinoma morphology is also mandatory in the current era of personalised medicine. Notably, cytology specimens in different forms (fine needle aspiration, exfoliative, and cell block) with or without immunocytochemistry are reliable sources for accurate diagnosis of adenocarcinoma and squamous cell carcinoma as evidenced by numerous studies present in the literature. However, there are instances where subtyping of NSCLC based on morphology alone is challenging on cytology samples, especially non-cell block preparations. In this paper, we will discuss current concepts, advances, and challenges of subtyping NSCLC in cytology specimens.

Molecular cytology of the respiratory tract and pleura

There is growing evidence that molecular testing is feasible on all types of cytological preparation, which is fortunate as more diagnostic markers and biomarkers for targeted therapies are discovered for use in pulmonary and pleural malignancies. In this article we will discuss the pre-analytic, analytic, and post-analytic (interpretive) considerations for successful implementation of molecular tests for diagnostic and predictive markers in respiratory and pleural cytology. The vast majority of laboratories are familiar with, and have validated their molecular protocols for, formalin-fixed paraffin-embedded surgical specimens, which are not directly applicable to cytology specimens. Thus, rigorous validation must be performed for each type of fixative and cytology preparation before it is implemented in the clinical setting.

Respiratory cytology in malignant lung disease - The thoracic oncologist's perspective

Respiratory cytology continues to play a central role in the diagnosis and staging of thoracic malignancy, although over time indications have changed. Historically, sputum cytology and endobronchial brushings and washings figured prominently, but with the advent of endobronchial and endoscopic ultrasound much greater emphasis is placed on fine needle aspirates from lymph nodes. The advent of targeted sequencing panels for genomic profiling to identify driver mutations and PD-L1 directed immunotherapy means that there is a need to extract increasing amounts of diagnostic and predictive information from ever smaller amounts of diagnostic material. Recent work has demonstrated that cytology samples are well suited to delivering the information required, but in order to understand the limitations of clinical and laboratory techniques, a close working relationship between pathologist and thoracic oncologist is needed to optimise sample procurement and utilisation.

Advances in cytology of lung cancer

Cytopathology has emerged as a promising platform in precision oncology especially after the revolutionary change in our understanding of the concept of lung cancer etiopathogenesis. With increasing use of minimally invasive techniques for sample acquisition, it becomes almost mandatory to utilize precious cytology samples maximally and judiciously by appropriate triaging of the specimen and timely action of the cytopathology team. Existing patient management protocols require accurate morphologic and molecular diagnosis of the lung cancer specimens which needs knowledge about evolving techniques related to specimen procurement, updates of genomic variants of lung cancer and recently developed molecular testing platforms and algorithms which are capable enough to use even miniscule amount of diagnostic material. This review provides a brief knowledge about advances in cytology of lung cancer which are helpful for developing correct clinical management strategies.

Adequacy of small biopsy and cytology specimens for comprehensive genomic profiling of patients with non-small-cell lung cancer to determine eligibility for immune checkpoint inhibitor and targeted therapy

AIMS

In advanced-stage non-small-cell lung cancer (NSCLC), incomplete genotyping for guideline-recommended genomic biomarkers poses a significant challenge to making informed and timely clinical decisions. We report our institution's experience in assessing the adequacy of small specimens for comprehensive genomic profiling for guideline-recommended lung cancer biomarker testing.

METHODS

We performed a retrospective evaluation of all image-guided procedures for NSCLC performed in our institution between October 2016 and July 2018, including core needle biopsy (CNB) and fine-needle aspiration (FNA) in patients who had undergone genomic profiling for lung cancer. Lung cancer biomarker adequacy, defined as successful testing of guideline-recommended biomarkers including, epidermal growth factor receptor (EGFR); serine/threonine protein kinase B-Raf (BRAF); anaplastic lymphoma kinase (ALK); proto-oncogene tyrosine protein kinase ROS (ROS1); Rearranged during Transfection (RET); Tyrosine protein kinase Met (MET); and programmed cell death ligand 1 (PD-L1), was evaluated.

RESULTS

A total of 865 cases were evaluated in this study, 785 of which included testing of all lung cancer biomarkers. Lung tissue was adequate for biomarker testing in 84% of cases; this rate increased to 87% when biomarker testing was combined with concurrently acquired FNA or CNB specimens. Biomarker testing success correlated strongly with DNA concentration (p<0.0001) and the use of 22G needles in endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) procedures (p=0.0035). Biomarker testing of CNB specimens showed a significantly higher success rate than did biomarker testing of cytology FNA specimens (p=0.0005). The adequacy of EBUS-TBNA samples was not significantly different from that of the transthoracic needle aspiration samples (p=0.40). Variables such as age, gender, lesion size, site, diagnosis and number of needle passes showed no significant correlation with success rates in lung cancer biomarker testing.

CONCLUSION

The growing numbers of therapeutic biomarkers in NSCLC requires judicious triage of limited-volume tissue from small specimens. Our study showed that thoracic small tissue specimens can be used successfully to provide prognostic and predictive information for the current guideline-recommended biomarkers for NSCLC in most cases.

Testing EGFR with Idylla on Cytological Specimens of Lung Cancer: A Review

The current standard of care for advanced non-small-cell lung cancer is based on detecting actionable mutations that can benefit from targeted therapy. Comprehensive genetic tests can have long turn-around times, and because EGFR mutations are the most prevalent actionable mutation, a quick detection would enable a prompt initiation of targeted therapy. Furthermore, the scarcity of diagnostic material means that sometimes only cytologic material is available. The Idylla™ EGFR assay is a real-time PCR–based method able to detect 51 EGFR mutations in 2.5 h. Idylla is validated for use only on FFPE sections, but some researchers described their experiences with cytological material. We reviewed the relevant literature, finding four articles describing 471 cases and many types of cytological input material: smears, cell-block sections, suspensions, and extracted DNA. The sensitivity, specificity, and limit of detection appear comparable to those obtained with histological input material, with one exception: the usage of scraped stained smears as input may reduce the accuracy of the test. In conclusion, usage of cytological material as input to the Idylla EGFR test is possible. A workflow where common mutations are tested first and fast, leaving rarer mutations for subsequent comprehensive profiling, seems the most effective approach.

Bronchial Washing Fluid Versus Plasma and Bronchoscopy Biopsy Samples for Detecting Epidermal Growth Factor Receptor Mutation Status in Lung Cancer

Background

Bronchial washing fluid (BWF) is a common specimen collected during bronchoscopy and has been suggested to contain both tumor cells and cell-free DNA. However, there is no consensus on the feasibility of BWF in epidermal growth factor receptor (EGFR) genetic analysis because of the limited sample size and varying results in previous studies. This study compared the feasibility, sensitivity, and specificity of detecting EGFR mutation using BWF, bronchoscopy biopsy, and plasma samples in patients with lung cancer (LC).

Materials and Methods

A total of 144 patients (110 with LC and 34 without LC) were enrolled in the study. During diagnostic bronchoscopy for suspected LC lesions, bronchial washing with saline was performed directly or through a guide sheath. BWF was collected as well as paired bronchoscopy biopsy and plasma samples, and EGFR mutation testing was performed via highly sensitive blocker polymerase chain reaction. The EGFR mutation status of histologic samples was set as the standard reference.

Results

Compared with the histologic samples, the sensitivity, specificity, and concordance rate of EGFR mutation detected in BWF samples were 92.5%, 100%, and 97.9%, respectively. Moreover, BWF showed a higher sensitivity in EGFR mutation testing than both plasma (100% [8/8] vs. 62.5% [5/8], p = 0.095) and bronchoscopy biopsy samples (92.5% [37/40] vs. 77.5% [31/40], p = 0.012) and identified EGFR mutations in 6 cases whose biopsy failed to establish an LC diagnosis. The diameter of the target lesion and its contact degree with BWF were positive predictive factors for EGFR testing results.

Conclusions

BWF yields a high sensitivity in EGFR mutation testing, having high concordance with histologic samples, and presenting the benefit of rapid EGFR mutation detection in LC patients.

Cell-blocks and other ancillary studies (including molecular genetic tests and proteomics)

Many types of elective ancillary tests may be required to support the cytopathologic interpretations. Most of these tests can be performed on cell-blocks of different cytology specimens. The cell-block sections can be used for almost any special stains including various histochemistry stains and for special stains for different microorganisms including fungi, Pneumocystis jirovecii (carinii), and various organisms including acid-fast organisms similar to the surgical biopsy specimens. Similarly, in addition to immunochemistry, different molecular tests can be performed on cell-blocks. Molecular tests broadly can be divided into two main types Molecular genetic tests and Proteomics.

Fine-needle aspiration as an alternative to core needle biopsy for tumour molecular profiling in precision oncology: prospective comparative study of next-generation sequencing in cancer patients included in the SHIVA02 trial

High-throughput molecular profiling of solid tumours using core needle biopsies (CNB) allows the identification of actionable molecular alterations, with around 70% success rate. Although several studies have demonstrated the utility of small biopsy specimens for molecular testing, there remains debate as to the sensitivity of the less invasive fine-needle aspiration (FNA) compared to CNB to detect molecular alterations. We aimed to prospectively evaluate the potential of FNA to detect such alterations in various tumour types as compared to CNB in cancer patients included in the SHIVA02 trial. An in-house amplicon-based targeted sequencing panel (Illumina TSCA 99.3 kb panel covering 87 genes) was used to identify pathogenic variants and gene copy number variations (CNV) in concomitant CNB and FNA samples obtained from 61 patients enrolled in the SHIVA02 trial (NCT03084757). The main tumour types analysed were breast (38%), colon (15%), pancreas (11%), followed by cervix and stomach (7% each). We report 123 molecular alterations (85 variants, 23 amplifications and 15 homozygous deletions) among which 98 (80%) were concordant between CNB and FNA. The remaining discordances were mainly related to deletions status, yet undetected alterations were not exclusively specific to FNA. Comparative analysis of molecular alterations in CNB and FNA showed high concordance in terms of variants as well as CNVs identified. We conclude FNA could therefore be used in routine diagnostics workflow and clinical trials for tumour molecular profiling with the advantages of being minimally invasive and preserve tissue material needed for diagnostic, prognostic or theranostic purposes.

Diagnostic utility of fine needle aspiration cytology and core biopsy histopathology with or without immunohistochemical staining in the subtyping of the non-small cell lung carcinomas: Experience from an academic centre in Turkey

INTRODUCTION

This retrospective morphological study compared the results of fine needle aspiration (FNA) cytology, haematoxylin-eosin (HE)-stained samples and immunohistochemical (IHC)-stained core needle biopsy (CNB) histology samples for primary non-small cell lung cancer (NSCLC) subtyping. We assessed the diagnostic utility of these methods to investigate the contribution of each method to NSCLC subtyping. We also identified the point at which NSCLC subtyping could be performed using histomorphology alone without IHC.

METHODOLOGY

Concurrent FNA and CNB specimens obtained via a single computed tomography-guided procedure and diagnosed as NSCLC in the Pathology Department of our university within 3 years were reviewed. The results of FNA samples, HE-stained biopsies and IHC-stained biopsies were compared according to subtype.

RESULTS

A total of 141 subjects were enrolled in the study. For subtyping, FNA provided an accurate diagnosis in 70 (55.1%) of 127 eligible subjects after the exclusion of 14 cases determined as not otherwise specified. CNB histology without IHC achieved a diagnosis in 53 (41.7%) of 127 subjects, which was a significant difference (P < .05). The compatibility rate between HE-stained biopsy samples and IHC-stained biopsy samples was 41.7% (53/127).

CONCLUSION

The diagnosis rates achieved using FNA, HE-stained CNB samples and IHC-stained CNB samples were 54.6% (77/141), 37.6% (53/141) and 90.1% (127/141), respectively. The subtype was identified in 55.1% of the subjects evaluated using FNA and 41.7% of subjects assessed using HE-stained biopsy samples without IHC. FNA provided a better result for squamous cell carcinoma than adenocarcinoma (55.1% vs 47.6%), but the diagnosing of adenocarcinoma and squamous cell carcinoma using HE-stained biopsy samples was similar (42% vs 41.7%).

Prospective Evaluation of Single Nucleotide Variants by Two Different Technologies in Paraffin Samples of Advanced Non-Small Cell Lung Cancer Patients

Targeted therapies are a new paradigm in lung cancer management. Next-generation sequencing (NGS) techniques have allowed for simultaneous testing of several genes in a rapid and efficient manner; however, there are other molecular diagnostic tools such as the nCounter® Vantage 3D single nucleotide variants (SNVs) solid tumour panel which also offer important benefits regarding sample input and time-to-response, making them very attractive for daily clinical use. This study aimed to test the performance of the Vantage panel in the routine workup of advanced non-squamous non-small cell lung cancer (NSCLC) patients and to validate and compare its outputs with the Oncomine Solid Tumor (OST) panel DNA kit, the standard technique in our institution. Two parallel multiplexed approaches were performed based on DNA NGS and direct digital detection of DNA with nCounter® technology to evaluate SNVs. A total of 42 advanced non-squamous NSCLC patients were prospectively included in the study. Overall, 95% of samples were successfully characterized by both technologies. The Vantage panel accounted for a sensitivity of 95% and a specificity of 82%. In terms of predictive values, the probability of truly presenting the SNV variant when it is detected by the nCounter panel was 82%, whereas the probability of not presenting the SNV variant when it is not detected by the platform was 95%. Finally, Cohen's Kappa coefficient was 0.76, indicating a substantial correlation grade between OST and Vantage panels. Our results make nCounter an analytically sensitive, practical and cost-effective tool.

Diagnostic patterns of non-small-cell lung cancer at Princess Margaret Cancer Centre

Background

Accurate classification of lung cancer subtypes has become critical in tailoring lung cancer treatment. Our study aimed to evaluate changes in diagnostic testing and pathologic subtyping of advanced non-small-cell lung cancer (nsclc) over time at a major cancer centre.

Methods

In a review of patients diagnosed with advanced nsclc at Princess Margaret Cancer Centre between 2007-2009 and 2013-2015, diagnostic method, sample type and site, pathologic subtype, and use of immunohistochemistry (ihc) staining and molecular testing were abstracted.

Results

The review identified 238 patients in 2007-2009 and 283 patients in 2013-2015. Over time, the proportion of patients diagnosed with adenocarcinoma increased to 73.1% from 60.9%, and diagnoses of nsclc not otherwise specified (nos) decreased to 6.4% from 18.9%, p < 0.0001. Use of diagnostic bronchoscopy decreased (26.9% vs. 18.4%), and mediastinal sampling procedures, including endobronchial ultrasonography, increased (9.2% vs. 20.5%, p = 0.0001). Use of ihc increased over time to 76.3% from 41.6% (p < 0.0001). Larger surgical or core biopsy samples and those for which ihc was performed were more likely to undergo biomarker testing (both p < 0.01).

Conclusions

Customizing treatment based on pathologic subtype and molecular genotype has become key in treating patients with advanced lung cancer. Greater accuracy of pathology diagnosis is being achieved, including through the routine use of ihc.

Lung Cancer Cytology: Can Any of the Cytological Methods Replace Histopathology?

Background:

Diagnosis of lung cancer can be made in two ways: histopathological and cytopathological. Cytological methods in the diagnosis of lung lesions are generally thought to be one of the most successful tactics.

Aims:

This study aimed at comparing the efficiency of selected cytological techniques in lung lesions by correlating them with histopathological diagnosis. In addition, we had answered the question whether any of the cytological methods can replace histopathology.

Materials and Methods:

The study group consisted of 633 patients and 1085 cytological specimens. Cytology samples included: induced sputum, bronchial washing (BW), bronchial brushing (BB), fine needle aspiration (FNA), and cell block (CB). In every case of CB immunocytochemistry (ICC) was performed. For each cytological method sensitivity, specificity, effectiveness, positive predictive value, and negative predictive value were assessed.

Results:

BW and BB showed the lowest diagnostic parameters. The most valuable diagnostic procedure was CB based on FNA. Close by CB, FNA had the highest diagnostic rate. However, possibility to evaluate tumor cell structure and apply the ICC, give CB an advantage over FNA. Using only morphologic criteria, we had subclassified nonsmall-cell lung cancer (NSCLC) into squamous cell carcinoma (SCC) and adenocarcinoma (AC) as 60.04% of SCC and 32.52% of AC. The use of CB and ICC decreased the NSCLC diagnoses from 22.1% to 2.8% while the percentage of AC and SCC diagnoses increased from 4.11% to 12.64% and from 6.64% to 11.06%, respectively. Metastatic lung tumors were diagnosed based on both the cell morphology and according to the ICC results.

Conclusion:

Despite the limitations of the cytological procedures, we recommend using CB and ICC to evaluate cytological samples derived from FNA. It can in many cases replace a conventional histopathology.

Detailed procedure and clinical application overview of rapid on-site evaluation in diagnostic interventional pulmonology

Diagnostic interventional pulmonology is widely accepted as a minimally invasive, highly accurate procedure for diagnosing lung cancer, more drug-resistant pathogen infections of lower respiratory tract, and critical respiratory diseases. The efficiency of interventional diagnostics depends on quite a few factors, including size and the anatomic location of lymph nodes, number of biopsy sites and complications rate, characteristics of the lesion, and underlying disease. Specifically, the application of rapid on-site evaluation (ROSE) may avoid additional sampling without compromising diagnostic yield with a preliminary evaluation for adequate diagnostic material and thus reduce the complication rate. In this review article we aimed at elaborate the technical details, clinical roles, and technological progress of ROSE in diagnostic interventional pulmonology, highlighting the importance of ROSE in diagnostic interventional pulmonology. We finally pointed out that it will be a tendency for a pulmonologist, to undergo a short yet intensive training and perform ROSE in diagnostic interventional pulmonology.

Lung cancer cytology and small biopsy specimens: diagnosis, predictive biomarker testing, acquisition, triage, and management

In the 21st century, there has been a dramatic shift in the management of advanced-stage lung carcinoma, and this has coincided with an increasing use of minimally invasive tissue acquisition methods. Both have had significant downstream effects on cytology and small biopsy specimens. Current treatments require morphologic, immunohistochemical, and/or genotypical subtyping of non-small cell lung carcinoma. To meet these objectives, standardized classification of cytology and small specimen diagnoses, immunohistochemical algorithms, and predictive biomarker testing guidelines have been developed. This review provides an overview of current classification, biomarker testing, methods of small specimen acquisition and triage, clinical management strategies, and emerging technologies.

Adenocarcinoma of the lung: from BAC to the future

Adenocarcinoma in situ, minimally invasive adenocarcinoma, lepidic predominant adenocarcinoma and invasive mucinous adenocarcinoma are relatively new classification entities which replace the now retired term, bronchoalveolar carcinoma (BAC). The radiographic appearance of these lesions ranges from pure, ground glass nodules to large, solid masses. A thorough understanding of the new classification is essential to radiologists who work with MDT colleagues to provide accurate staging and treatment. A 2-year review was performed of all surgically resected cases of adenocarcinoma in situ, minimally invasive adenocarcinoma and lepidic predominant adenocarcinoma in our institution. Cases are broken down by age, gender, tumour type and tumour location. A pictorial review is presented to illustrate the radiologic and pathologic features of each entity.

Lung Cancer Pathology: Current Concepts

Lung cancer can be diagnosed based on histologic biopsy or cytologic specimens. The 2015 World Health Organization Classification of Lung Tumors addressed the diagnosis of lung cancer in resection specimens and in small biopsies and cytology specimens. For these small specimens, diagnostic terms and criteria are recommended. Targetable mutations such as EGFR and ALK rearrangements emphasize the importance of managing these small specimens for molecular testing.

Challenges for real-time intraoperative diagnosis of high risk histology in lung adenocarcinoma: A necessity for sublobar resection

Recently, the incidence of small, peripheral lung adenocarcinoma has been increasing as lung cancer screening with radiologic examination is more widely performed. Tumor size is one of the determinants of the prognostic outcome in clinically node-negative lung adenocarcinoma. Sublobar resection has been proposed as one of the minimally invasive surgical options for small-sized adenocarcinomas. Despite the lack of robust clinical trial evidence, sublobar resection has become more popular, especially in developed countries where less extensive surgery may be of benefit in a population where the age of the elderly is growing. However, high risk histologic features such as micropapillary subtype and tumor spread through air space (STAS) have been associated with a significantly higher risk of local recurrence after sublobar resection, but not after lobectomy. Surgical decision-making based on frozen section diagnosis of high risk histologic features may be useful to prevent local control failure after sublobar resection. At the present time, there is little evidence to demonstrate the diagnostic accuracy of identifying high risk histologic features on frozen section. One study has so far demonstrated that diagnostic accuracy of identifying STAS is higher than that of identifying the micropapillary subtype. Additionally, the presence of STAS has been found to be more strongly associated with local recurrence in patients who had undergone sublobar resection. Although further investigation is required for validation of this finding, STAS diagnosis on frozen section may shed further light on intraoperative surgical decision-making during sublobar resection. To this end, we review the recently published data on the intraoperative identification of high risk features.

Cytomorphological criteria for separation of pulmonary adenocarcinomas from squamous cell carcinomas: A statistical learning approach

BACKGROUND

Current therapy requires separation of non-small cell carcinomas into adenocarcinomas (AC) and squamous cell carcinomas (SCC). A meta-analysis has shown a pooled diagnostic sensitivity of 63% and specificity of 95% for the diagnosis of AC. While a number of cytomorphological features have been proposed for separation of AC from SCC, we are unaware of a statistically based analysis of cytomorphological features useful for separation of these two carcinomas. We performed logistic regression analysis of cytological features useful in classifying SCC and AC.

DESIGN

Sixty-one Papanicolaou-stained fine needle aspiration specimens (29 AC/32 SCC) were reviewed by two board-certified cytopathologists for nine features (eccentric nucleoli, vesicular chromatin, prominent nucleoli, vacuolated cytoplasm, 3-dimensional cell balls, dark non-transparent chromatin, central nucleoli, single malignant cells and spindle-shaped cells). All cytological specimens had surgical biopsy results. Inter-rater agreement was assessed by Cohen's κ. Association between features and AC was determined using hierarchical logistic regression model where feature scores were nested within reviewers. A model to classify cases as SCC or AC was developed and verified by k-fold verification (k = 5). Classification performance was assessed using the area under the receiver operating characteristic curve.

RESULTS

Observed rater agreement for scored features ranged from 49% to 82%. Kappa scores were clustered in three groups. Raters demonstrated good agreement for prominent nucleoli, vesicular chromatin and eccentric nuclei. Fair agreement was seen for 3-dimensional cell balls, dark non-transparent chromatin, and presence of spindle-shaped cells. Association of features with adenocarcinoma showed four statistically significant associations (P < 0.001) with adenocarcinoma. These features were prominent nucleoli, vesicular chromatin, eccentric nuclei and three-dimensional cell balls. Spindle-shaped cells and dark non-transparent chromatin were negatively associated with adenocarcinoma.

CONCLUSIONS

Logistic regression analysis demonstrated six features helpful in separation of AC from SCC. Prominent nucleoli, vesicular chromatin, cell balls and eccentric nucleoli were positively associated with AC and demonstrated a P value of 0.001 or less. The presence of dark, non-transparent chromatin and spindle-shaped cells favoured the diagnosis of SCC.

Baseline predictors of negative and incomplete pleural cytology in patients with suspected pleural malignancy - Data supporting 'Direct to LAT' in selected groups

OBJECTIVES

Negative effusion cytology is more common in certain forms of Malignant Pleural Effusion (MPE) and results in pathway delay. Local Anaesthetic Thoracoscopy (LAT) is extremely sensitive and safe but cannot be offered to all. A stratified pathway, including 'Direct to LAT' in selected cases could enhance patient experience but requires reliable baseline predictors of unhelpful cytology, including both negative (no malignant cells) and incomplete results (malignant cells identified but predictive markers failed), since pleural biopsies will be required in the latter for optimal management. This retrospective analysis of a prospective multi-centre study, sought to identify baseline features for pathway rationalization.

MATERIALS AND METHODS

363/638 (57%) of patients recruited to the DIAPHRAGM study (ISRCTN10079972) were included. Prospective data, including final diagnoses, asbestos exposure and fluid cytology results were supplemented by retrospective Computed Tomography (CT) and predictive marker reports. Independent predictors of negative and incomplete cytology were determined by multivariable logistic regression. Contingency tables were used to assess diagnostic value of cytology in associated phenotypes.

RESULTS

238/363 (66%) patients were diagnosed with MPE (18 tumour types). Fluid cytology was negative in 151/238 (63%) and independently associated with asbestos-exposure (Odds Ratio (OR) 5.34) and a malignant CT (OR 2.25). When both features were recorded the sensitivity and negative predictive value of fluid cytology were 19% (95% CI 11-30%) and 9% (95% CI 4-20%)), respectively. Cytology was incomplete in 34/238 (14%), i.e. 47% of positive cytology cases) but was not associated with any baseline feature. ORs for incomplete cytology in Ovarian, Breast, Renal and Lung Cancer were 83, 22, 21 and 9, respectively.

CONCLUSION

Negative cytology is extremely likely in patients with asbestos exposure and a malignant CT report. A 'Direct-to-LAT' approach may be appropriate in this setting. No baseline predictors of incomplete cytology were identified.

Role of Immunocytochemistry in the Cytological Diagnosis of Pulmonary Tumors

Pulmonary cytology is a challenging diagnostic tool, and it is usually evaluated considering medical history and radiological findings in order to reach an accurate diagnosis. Since the majority of lung cancer patients have an advanced stage at diagnosis, a cytological specimen is frequently the only material available for diagnosis and further prognostic/predictive marker determination. Several types of specimens can be obtained from the respiratory system (including sputum, bronchoalveolar lavage, bronchial brushing, fine needle aspiration, and pleural fluid) with different technical preclinical management protocols and different diagnostic yields. Immunocytochemistry (ICC) has a pivotal role in the determination of diagnostic, prognostic, and predictive markers. Therefore, limited cytology samples are to be used with a cell-sparing approach, to allow both diagnostic ICC evaluation as well as predictive marker assessment by ICC or specific molecular assays. In this review, we describe the most common ICC markers used for the diagnosis and prognostic/predictive characterization of thoracic tumors in different cytological specimens.

Cytology Smears in the Era of Molecular Biomarkers in Non-Small Cell Lung Cancer: Doing More With Less

CONTEXT

- The rapid advances in targeted therapies in non-small cell lung cancer (NSCLC) make the optimization and implementation of cytology specimens for molecular testing a priority. Up to 70% of patients with NSCLC are diagnosed at advanced stages and tissue biopsies often cannot be taken. Although cytology samples provide high-quality material for molecular testing, molecular cytopathology is not yet well known or widely used.

OBJECTIVE

- To report the many advances in molecular cytopathology and the suitability and utility of cytology samples in molecular and genetic testing of NSCLC.

DATA SOURCES

- Data sources comprised published peer-reviewed literature and personal experience of the authors.

CONCLUSIONS

- Molecular testing can be performed on cytologic specimens, especially on direct smears. Rapid on-site evaluation by cytopathologists has improved the adequacy and the management of cytology samples for molecular testing. Mutational profiling of NSCLC using next-generation sequencing can be performed on cytology samples from very small amounts of DNA. Fluorescence in situ hybridization assays on cytology specimens, including stained direct smear, offer some distinct advantages over their histologic counterpart, and are used to detect ALK and ROS1 rearrangements in NSCLC. Cytology specimens allow assessment of the entire tumor cell nucleus, avoiding signal loss from truncation artifacts. The use of cytology samples for assessing programmed death ligand-1 protein expression is currently being developed. Protocols for bisulfite conversion and DNA droplet digital polymerase chain reaction assays have been optimized for cytology smear to investigate aberrant DNA methylation of several NSCLC-related genes.

Molecular Testing in EBUS-TBNA Specimens of Lung Adenocarcinoma: A Study of Concordance Between Cell Block Method and Liquid-Based Cytology in Appraising Sample Cellularity and EGFR Mutations

PURPOSE

Cytological endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) specimens of mediastinal lymph node metastasis are frequently used to perform concomitant diagnosis, staging and genetic testing in non-small-cell lung cancer (NSCLC). The purposes of this single-center retrospective study were to evaluate EBUS-TBNA samples' adequacy for molecular testing of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK), and to analyze the concordance between the cell block method and liquid-based cytology (LBC) in appraising the sample cellularity and in detecting EGFR mutation.

MATERIALS AND METHODS

We retrospectively examined 82 patients who underwent EBUS-TBNA from October 2012 to September 2015 and received a confirmed diagnosis of lymph node metastasis of lung adenocarcinoma. Each sample was processed using both cell block and LBC to carry out DNA analysis (adequacy criterion: tumor cell percentage > 25%) and EGFR mutation testing.

RESULTS

Fifty-four patients were male, 66 were current or former-smokers, and the median age was 67 years. The median size of sampled lymph nodes was 14.8 mm. Seventy-one and 66 samples were adequate to perform cell block and LBC, respectively. The κ-statistic (0.78) showed an excellent concordance. EGFR mutation was detected in eight patients using cell block and in seven using LBC, with a simple percentage agreement of 87.5%. ALK translocation was found in two patients.

CONCLUSIONS

This study demonstrates the feasibility of EGFR mutation analysis with both cell block and LBC, with an excellent concordance between the two methods. Considering that the majority of advanced NSCLCs are diagnosed on cytology specimens, LBC is feasible and needs to be implemented for ancillary tests (immunocytochemistry, molecular analysis).

Pan-Asian adapted Clinical Practice Guidelines for the management of patients with metastatic non-small-cell lung cancer: a CSCO-ESMO initiative endorsed by JSMO, KSMO, MOS, SSO and TOS

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of metastatic non-small-cell lung cancer (NSCLC) was published in 2016. At the ESMO Asia Meeting in November 2017 it was decided by both ESMO and the Chinese Society of Clinical Oncology (CSCO) to convene a special guidelines meeting immediately after the Chinese Thoracic Oncology Group Annual Meeting 2018, in Guangzhou, China. The aim was to adapt the ESMO 2016 guidelines to take into account the ethnic differences associated with the treatment of metastatic NSCLC cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with metastatic NSCLC representing the oncological societies of China (CSCO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence, and was independent of both the current treatment practices and the drug availability and reimbursement situations in the six participating Asian countries. During the review process, the updated ESMO 2018 Clinical Practice Guidelines for metastatic NSCLC were released and were also considered, during the final stages of the development of the Pan-Asian adapted Clinical Practice Guidelines.

Rapid on-site evaluation using telecytology: A major cancer center experience

BACKGROUND

Rapid on-site evaluation (ROSE) with cytology preparations plays a critical role in minimally invasive procedures. The time spent by a pathologist performing ROSE is unpredictable and could be used for more cost-effective activities. The solution encountered by several institutions to address this issue is the use of telecytology (TC). This study analyzes the experience of using telecytology for ROSE in a major cancer center over a period of over 2 years.

METHODS

A retrospective analysis of all remote TC evaluations for adequacy on fine needle aspiration (FNA) and touch preparations (TP) of core biopsies (CB) performed at a major cancer center was performed. The preliminary adequacy assessment was then compared to the adequacy assessment at final diagnosis.

RESULTS

A total of 12 949 adequacy assessments were analyzed. The most common sites biopsied in our institution were lymph node, lung, and liver. There were 7725 adequacy assessments for CB (59.7%), while adequacy assessment for FNA specimens represented 40.3% (n = 5224) of the total number of specimens evaluated by ROSE. Perfect concordance between initial adequacy assessment and the adequacy assessment at final cytologic diagnosis was 93% (12 049/12 949). The final diagnosis adequacy upgrade rate was 6.7% (n = 863), and the adequacy downgrade (a specimen considered adequate on-site that was determined to be nondiagnostic on final examination) was 0.3% (n = 37).

CONCLUSIONS

TC can be easily implemented with the current technologies available. It is cost-effective and allows for better patient care with a more efficient use of the pathologist's time and laboratory resources.

[2018 Consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology on the diagnosis and treatment of cancer of unknown primary]

Cancer of unknown primary is defined as a heterogeneous group of tumours that present with metastasis, and in which attempts to identify the original site have failed. They differ from other primary tumours in their biological features and how they spread, which means they can be considered a separate entity. There are several hypotheses regarding their origin, but the most plausible explanation for their aggressiveness and chemoresistance seems to involve chromosomal instability. Depending on the type of study done, cancer of unknown primary can account for 2-9% of all cancer patients, mostly 60-75 years old. This article reviews the main clinical, pathological and molecular studies conducted to analyse and determine the origin of cancer of unknown primary. The main strategies for patient management and treatment, by both clinicians and pathologists, are also addressed.

The Differential Diagnosis in Nonlymphoproliferative Malignant Pleural Effusion Cytopathology and Its Correlation with Patients' Demographics

BACKGROUND

We report our experience with malignant pleural effusion (MPE) and the impact of patients' demographics on the differential diagnosis at the primary site.

METHODS

After IRB approval, we searched our pathology database from January 2013 to January 2017 for patients with positive pleural effusions (PEs). Patients' demographics and clinical histories were noted.

RESULTS

474 patients were identified (288 females [61%] and 186 males [39%]), ranging in age from 19 to 64 years old. Ethnicity was distributed as follows: Caucasian (n = 330, 70%), African American (n = 114, 24%) and Asian (n = 30, 6%). The most common primary sites were the lung (n = 180, 37%), followed by the breast (n = 81, 17%), and the gynecologic system (67, 13%). The lung was the most common primary for all ethnicities (n = 190, 40%). The second-most common primary site was the breast in African Americans and Caucasians and upper gastrointestinal (GI) tract in Asians. In 5 cases (1%), the primary tumor could not be determined.

CONCLUSION

Cytology examination is a useful method to diagnose primary sites of PE. Pulmonary primary is the most common cause of effusion in all ethnicities. In African American and Caucasian patients, the breast was the second-most common site of MPE, while in Asian patients it was the upper GI tract.

Diagnosing Lung Cancer: The Complexities of Obtaining a Tissue Diagnosis in the Era of Minimally Invasive and Personalised Medicine

The role of the respiratory physician in diagnosing lung cancer has increased in complexity over the last 20 years. Adenocarcinoma is now the prevailing histopathological sub-type of non-small cell lung cancer (NSCLC) resulting in more peripheral cancers. Conventional bronchoscopy is often not sufficient to obtain adequate tissue samples for diagnosis. Radiologically guided transthoracic biopsy is a sensitive alternative, but carries significant risks. These limitations have driven the development of complimentary bronchoscopic navigation techniques for peripheral tumour localisation and sampling. Furthermore, linear endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) is increasingly being chosen as the initial diagnostic procedure for those with central lesions and/or radiological evidence of node-positive disease. This technique can diagnose and stage patients in a single, minimally invasive procedure with a diagnostic yield equivalent to that of surgical mediastinoscopy. The success of molecular targeted therapies and immune checkpoint inhibitors in NSCLC has led to the increasing challenge of obtaining adequate specimens for accurate tumour subtyping through minimally invasive procedures. This review discusses the changing epidemiology and treatment landscape of lung cancer and explores the utility of current diagnostic options in obtaining a tissue diagnosis in this new era of precision medicine.

2018 consensus statement by the Spanish Society of Pathology and the Spanish Society of Medical Oncology on the diagnosis and treatment of cancer of unknown primary

Cancer of unknown primary (CUP) is defined as a heterogeneous group of tumours that present with metastasis, and in which attempts to identify the original site have failed. They differ from other primary tumours in their biological features and how they spread, which means that they can be considered a separate entity. There are several hypotheses regarding their origin, but the most plausible explanation for their aggressiveness and chemoresistance seems to involve chromosomal instability. Depending on the type of study done, CUP can account for 2–9% of all cancer patients, mostly 60–75 years old. This article reviews the main clinical, pathological, and molecular studies conducted to analyse and determine the origin of CUP. The main strategies for patient management and treatment, by both clinicians and pathologists, are also addressed.

Feasibility of endobronchial ultrasound transbronchial needle aspiration for massively parallel next-generation sequencing in thoracic cancer patients

INTRODUCTION

Next-generation sequencing (NGS) allows for the identification of a growing number of therapeutic and prognostic molecular targets. However, NGS typically requires greater quantities of DNA than traditional molecular testing does. Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive procedure used to sample central thoracic lesions, but it is not well established whether this technique provides sufficient material for NGS.

METHODS

We performed a retrospective review of EBUS-TBNA at our institution (3/1/14-9/28/16). NGS was performed using a comprehensive hybrid-capture based assay (MSK-IMPACT) that detects >340 gene mutations. Samples found to be diagnostic for malignancy and for which MSK-IMPACT had been attempted were identified. Pathologic and clinical data were obtained from the medical record, and the results of MSK-IMPACT were examined.

RESULTS

In total, 784 EBUS-TBNA procedures were performed during the study period. MSK-IMPACT was requested for 115 malignant samples and was successful for 99 (86.1%), identifying an average of 12.7 mutations at a mean coverage depth of 806X. NGS was performed on paraffin-embedded cell blocks in 93 cases (93.9%) and on cell-free DNA in needle rinse fluid in 6 cases. The success rate of the assay improved significantly from the first third of cases (76.3%), to 92.3% for the final one-third of cases (p < 0.05).

CONCLUSIONS

EBUS-TBNA reliably provided adequate tissue for hybrid capture NGS, and is a suitable option for comprehensive NGS testing in patients with thoracic malignancies.

Pulmonary Non-Small Cell Carcinoma With Morphologic Features of Adenocarcinoma or "Non-Small Cell Carcinoma Favor Adenocarcinoma" in Cytologic Specimens Share Similar Clinical and Molecular Genetic Characteristics

OBJECTIVES

Define if the presence of morphologic features of adenocarcinoma (ACA) in non-small cell lung carcinoma (NSCLC) on cytology specimens correlates with clinical and biologic features.

METHODS

A total of 209 cases of NSCLC diagnosed on fine-needle aspiration in a 3-year period were included.

RESULTS

After morphologic review, the cases were classified as ACA (n = 115), NSCLC favor ACA (n = 43), and NSCLC-not otherwise specified (NOS) (n = 18). Squamous cell (SCC) (n = 14) and NSCLC favor SCC (n = 19) were excluded from further analysis. Patients with EGFR-mutated tumors had longer overall survival than those with EGFR wild-type tumors (P = .01). When comparing cases with morphologic features of ACA, NSCLC favor ACA, and NSCLC-NOS, there were no differences in the presence or absence of tested mutations, clinical stage, or survival.

CONCLUSION

Patients diagnosed with pulmonary ACA, NSCLC favor ACA, or NSCLC-NOS in cytology specimens have similar clinical stage, survival, and molecular alterations.

The value of radial endobronchial ultrasound-guided bronchial brushing in peripheral non-squamous non-small cell lung cancer

Radial endobronchial ultrasound (R-EBUS) is one important diagnostic approach in non-small cell lung cancers (NSCLC). However, the small samples obtained from R-EBUS-guided transbronchial biopsies are sometimes insufficient for pathological and molecular diagnosis. Herein, we investigated the suitability of R-EBUS-guided bronchial brushing specimens for NSCLC diagnosis and EGFR genotyping. We enrolled 941 consecutive patients with peripheral pulmonary lesions who underwent R-EBUS. Cytology-positive brushing specimens from non-squamous NSCLC patients were tested for EGFR mutations. Non-squamous NSCLC was diagnosed in 624 patients (66.3%). Positive cytology was documented in the brushing samples of 376 patients (60.3%). Higher diagnostic yields were obtained in patients exhibiting bronchus signs on chest tomography, and those with R-EBUS probe located within the lesion. EGFR genotyping was successfully performed in 363 samples (96.5% of cytology-positive brushing samples). EGFR genotyping concordance between brushing specimens and matched tissue samples was 88.7% (kappa = 0.745, P < 0.001). Furthermore, 144 non-squamous NSCLC patients (23.1%) with failed pathological diagnosis or EGER sequencing by R-EBUS-guided transbronchial biopsy required repeat biopsies. However, it was achieved successfully from the brushing specimens of 57 patients (39.6%). In conclusion, for patients with peripheral lung cancer, R-EBUS-guided bronchial brushing could provide an additional sampling method for diagnosis and EGFR genotyping.

Cytomorphological features as predictors of epidermal growth factor receptor mutation status in lung adenocarcinoma

Background:

Epidermal growth factor receptor mutation-positive (EGFR-p) lung adenocarcinomas are sensitive to tyrosine kinase inhibitors. Although histopathological subtype is an independent predictor of mutation status, there is a paucity of data on the cytomorphological features correlating with the EGFR mutation status. Therefore, the aim of this study was to determine whether certain cytomorphological features correlate with EGFR mutation in lung adenocarcinoma.

Materials and Methods:

A retrospective analysis of 48 lung adenocarcinoma cases diagnosed on fine needle aspiration cytology with known EGFR mutation status was conducted. All cytology smears with cellblock sections were reviewed. The cytomorphological features including tumor pattern, stromal features, nuclear and cytoplasmic features, and tumor grade were evaluated. Clinicoradiological features such as age, sex, smoking, tumor size, clinical stage, metastases, and presence of mass, nodule, lymphadenopathy, pleural effusion, and clinical outcome were also assessed.

Results:

Of 48 cases, 19 were EGFR-p and 29 were negative. EGFR-p cases showed a positive and significant correlation with flat monolayered sheets and acini, mild nuclear atypia, fine chromatin and smooth nuclear margins and these tumors were well differentiated. EGFR-negative tumors were moderate to poorly differentiated with predominance of solid clusters, moderate to marked nuclear atypia, with irregular nuclear margins and coarse chromatin. Clinically, female sex, nonsmoking status, smaller tumor size, and good clinical outcome correlated with EGFR-p status.

Conclusion:

Certain cytomorphological features correlate with and may suggest EGFR mutation status in advanced lung adenocarcinoma in an appropriate clinical context.

Novel Modification of HistoGel-Based Cell Block Preparation Method: Improved Sufficiency for Molecular Studies

CONTEXT

- Cell block preparation methods vary substantially across institutions and are frequently suboptimal. The growing importance of biomarker testing in the era of targeted therapies makes optimization of cell block preparation critically important.

OBJECTIVE

- To develop an improved cell block preparation method.

DESIGN

- Ex vivo fine-needle aspirates and scrapes from surgically resected tumors were used to develop an improved HistoGel (Thermo Fisher Scientific, Waltham, Massachusetts)-based cell block preparation method. Cellularity yield with the new versus the standard method was assessed in ex vivo split samples and in consecutive clinical fine-needle aspirates processed before (n = 100) and after (n = 100) the new method was implemented in our laboratory. Sufficiency of cell block material for potential molecular studies was estimated by manual cell quantitation.

RESULTS

- The key modification in the new method was pretreatment of the pelleted cells with 95% ethanol before the addition of HistoGel (HistoGel + ethanol method). In addition, we optimized the melting conditions of HistoGel and added a dark, inorganic marker to the cell pellets to highlight the desired level of sectioning during microtomy. Cell blocks from ex vivo split samples showed that the HistoGel + ethanol method yielded, on average, an 8.3-fold (range, 1-20) greater cellularity compared with the standard HistoGel-only method. After the switch from the standard HistoGel method to the modified method in our clinical practice, sufficiency of positive fine-needle aspirates for some molecular studies increased from 72% to 97% ( P = .002).

CONCLUSIONS

- We describe a simple and readily adoptable modification of the HistoGel method, which results in substantial improvement in cell capture in cell blocks, leading to a significant increase in sufficiency for potential molecular and other ancillary studies.