Interobserver agreement in determining non-small cell lung cancer subtype in specimens acquired by EBUS-TBNA

Interobserver variability in cytopathology: How much do we agree?

Interobserver variability remains a major challenge for cytopathologists despite the development of standardized reporting and classification systems. Indeed, whereas moderate-to-good interobserver agreement is generally achievable when the differential diagnosis between benign and malignant entities is straightforward, high levels of variability make the diagnostic interpretation of atypical and suspicious samples not consistent. This review explores the landscape of interobserver agreement in cytopathology across different anatomical sites.

A Multicenter, Single-Arm, Prospective Trial Assessing the Diagnostic Yield of Electromagnetic Bronchoscopic and Transthoracic Navigation for Peripheral Pulmonary Nodules

Rationale: Strict adherence to procedural protocols and diagnostic definitions is critical to understand the efficacy of new technologies. Electromagnetic navigational bronchoscopy (ENB) for lung nodule biopsy has been used for decades without a solid understanding of its efficacy, but offers the opportunity for simultaneous tissue acquisition via electromagnetic navigational transthoracic biopsy (EMN-TTNA) and staging via endobronchial ultrasound (EBUS). Objective: To evaluate the diagnostic yield of EBUS, ENB, and EMN-TTNA during a single procedure using a strict a priori definition of diagnostic yield with central pathology adjudication. Methods: A prospective, single-arm trial was conducted at eight centers enrolling participants with pulmonary nodules (<3 cm; without computed tomography [CT]- and/or positron emission tomography-positive mediastinal lymph nodes) who underwent a staged procedure with same-day CT, EBUS, ENB, and EMN-TTNA. The procedure was staged such that, when a diagnosis had been achieved via rapid on-site pathologic evaluation, the procedure was ended and subsequent biopsy modalities were not attempted. A study finding was diagnostic if an independent pathology core laboratory confirmed malignancy or a definitive benign finding. The primary endpoint was the diagnostic yield of the combination of CT, EBUS, ENB, and EMN-TTNA. Measurements and Main Results: A total of 160 participants at 8 centers with a mean nodule size of 18 ± 6 mm were enrolled. The diagnostic yield of the combined procedure was 59% (94 of 160; 95% confidence interval [CI], 51-66%). Nodule regression was found on same-day CT in 2.5% of cases (4 of 160; 95% CI, 0.69-6.3%), and EBUS confirmed malignancy in 7.1% of cases (11 of 156; 95% CI, 3.6-12%). The yield of ENB alone was 49% (74 of 150; 95% CI, 41-58%), that of EMN-TTNA alone was 27% (8 of 30; 95% CI, 12-46%), and that of ENB plus EMN-TTNA was 53% (79 of 150; 95% CI, 44-61%). Complications included a pneumothorax rate of 10% and a 2% bleeding rate. When EMN-TTNA was performed, the pneumothorax rate was 30%. Conclusions: The diagnostic yield for ENB is 49%, which increases to 59% with the addition of same-day CT, EBUS, and EMN-TTNA, lower than in prior reports in the literature. The high complication rate and low diagnostic yield of EMN-TTNA does not support its routine use. Clinical trial registered with www.clinicaltrials.gov (NCT03338049).

CT-Guided Percutaneous Core Needle Biopsy in Typing and Subtyping Lung Cancer: A Comparison to Surgery

Background: Lung cancer histologic types and subtypes are closely associated with treatment selection and prognosis prediction. In this study, we aim to evaluate the suitability of computed tomography-guided percutaneous core needle biopsy (CT-guided PCNB) in typing and subtyping lung cancer. Methods: From August 2007 to December 2015, the patients who underwent CT-guided PCNB and lung lesion resection were retrospectively collected and analyzed. All pathological sections were reassessed in consensus by 2 junior pathologists (group A) and 2 senior pathologists (group B), respectively. All cases were diagnosed on 3 levels: first, malignant and benign diagnosis; second, histologic types diagnosis; and third, histologic subtypes diagnosis and compared with surgery results. Pearson chi-square test was used to compare the differences of diagnostic accuracy between pathologists in group A and group B. Results: A cohort of 160 patients was included in this study. On the first level, the diagnostic accuracy was 90.63% (group A) and 94.38% (group B), (P = .20). On the second level, the diagnostic accuracy for malignant lesions, adenocarcinoma (ADC), and squamous cell carcinoma (SQC) were, respectively, 72.66%, 84.72%, and 69.05% (group A) and 76.98%, 90.28%, and 71.43% (group B) (P > .05). On the third level, the diagnostic accuracy for ADC subtypes were 26.39% (group A) and 55.56% (group B) (P < 0.01); for SQC subtypes were 28.57% (group A) and 38.10% (group B) (P = 0.36). Conclusion: Small specimens obtained by CT-guided PCNB were suitable for the diagnosis of lung cancer histologic types, which may contribute to the selection of a suitable treatment strategy for the unresectable lung cancers. While for the diagnosis of subtypes, discussion with experienced pathologists was recommended.

Integrating endobronchial ultrasound bronchoscopy with molecular testing of immunotherapy biomarkers in non-small cell lung cancer

Immunotherapy has transformed treatment of advanced non-small-cell lung cancer (NSCLC) patients leading to remarkable long-term survival benefit. However, only about 20% of advanced NSCLC patients typically respond to immune checkpoint inhibitors (ICIs) that target the PD-1/PD-L1 pathway. The only validated biomarker for ICI therapy is the PD-L1 immunohistochemistry (IHC) test, which is considered an imperfect assay due to several variables including availability and integrity of tumour tissue, variability in staining/scoring techniques and heterogeneity in PD-L1 protein expression within and across tumour biopsies. Herein, we discuss integrating minimally invasive EBUS bronchoscopy procedures with novel molecular approaches to improve accuracy and sensitivity of PD-L1 testing. EBUS guided bronchoscopy facilitates repeated sampling of tumour tissue to increase the probability of detecting PD-L1 positive tumours. Since intra-tumoural PD-L1 (CD274) copy number is reported to be less heterogeneous than PD-L1 protein detection, quantifying PD-L1 transcript levels may increase detection of PD-L1 positive tumours. PD-L1 transcript levels show excellent concordance with PD-L1 IHC scoring and multiplex digital droplet PCR (ddPCR) assays that quantify absolute PD-L1 transcript copy number have been developed. ddPCR can also be automated for high throughput detection of low abundant variants with excellent sensitivity and accuracy to improve the broader application of diagnostic cut-off values. Optimizing diagnostic workflows that integrate optimal EBUS bronchoscopy procedures with emerging molecular ICI biomarker assays may improve the selection criteria for ICI therapy benefit.

A deep learning model for the classification of indeterminate lung carcinoma in biopsy whole slide images

The differentiation between major histological types of lung cancer, such as adenocarcinoma (ADC), squamous cell carcinoma (SCC), and small-cell lung cancer (SCLC) is of crucial importance for determining optimum cancer treatment. Hematoxylin and Eosin (H&E)-stained slides of small transbronchial lung biopsy (TBLB) are one of the primary sources for making a diagnosis; however, a subset of cases present a challenge for pathologists to diagnose from H&E-stained slides alone, and these either require further immunohistochemistry or are deferred to surgical resection for definitive diagnosis. We trained a deep learning model to classify H&E-stained Whole Slide Images of TBLB specimens into ADC, SCC, SCLC, and non-neoplastic using a training set of 579 WSIs. The trained model was capable of classifying an independent test set of 83 challenging indeterminate cases with a receiver operator curve area under the curve (AUC) of 0.99. We further evaluated the model on four independent test sets-one TBLB and three surgical, with combined total of 2407 WSIs-demonstrating highly promising results with AUCs ranging from 0.94 to 0.99.

Transoesophageal Fine Needle Aspiration of Pleural Metastasis Using EBUS Scope

Endoscopic ultrasound using convex endobronchial ultrasound probe (EUS-B) is an evolving diagnostic technique. We present a case of successful EUS-B biopsy of pleural metastasis in a patient with lung adenocarcinoma. This was an accurate, uncomplicated procedure and demonstrates the feasibility of EUS-B for pleural lesions.

Adequate tumour cellularity is essential for accurate PD-L1 immunohistochemistry assessment on cytology cell-block specimens

OBJECTIVES

PD-L1 immunohistochemistry (IHC) is an essential predictive biomarker for patients with non-small cell lung cancer (NSCLC), required to inform treatment decisions regarding anti-PD-1 immune checkpoint inhibitor therapy. This study aims to investigate the concordance between PD-L1 IHC assessed on NSCLC cytology and histology specimens and to determine the impactce of tumour cellularity.

METHODS

Matched cytology and histology NSCLC specimens were retrieved from the archives of the Royal Melbourne Hospital and the Royal Prince Alfred Hospital. PD-L1 IHC was performed concurrently on both specimens at the Peter MacCallum Cancer Centre using the SP263 assay kit on the Ventana Benchmark Ultra staining platform and scored by two experienced pathologists.

RESULTS

Overall agreement between matched cytology and histology specimens was good (intraclass correlation coefficient = 0.653, n = 58); however, markedly increased when the analysis was limited to cell-blocks with >100 tumour cells (intraclass correlation coefficient = 0.957, n = 29). Specificity at both 1% and 50% cut-offs was high regardless of cellularity; however, sensitivity decreased in samples with <100 tumour cells.

CONCLUSIONS

PD-L1 IHC on cytology cell-block specimens in NSCLC is an acceptable alternative to histological specimens, provided adequate tumour cells are present. Clinicians and pathologists should be mindful of the risk of false negative PD-L1 IHC in samples with low tumour cellularity, to avoid excluding patients from potentially beneficial treatment.

Diagnostic value of rapid on-site evaluation during endobronchial ultrasound with a guide sheath for peripheral pulmonary lesions

OBJECTIVE

To evaluate the applied value of rapid on-site evaluation during endobronchial ultrasound (EBUS) with a guide sheath for peripheral pulmonary lesions (PPLs).

METHODS

Consecutive patients who underwent EBUS with a guide sheath for PPLs at our hospital from December 2015 to June 2017 in this retrospective study. The samples obtained from each operation were made rapid on-site evaluation at the same time. The results of rapid on-site evaluation were compared with the pathological diagnosis.

RESULTS

A total of 127 PPLs in 124 patients were included in the study. 70 lesions were malignancy in the final pathological diagnosis. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of rapid on-site evaluation for malignancy during EBUS with a guide sheath for PPLs was 88.6%, 98.2%, 98.4%, 87.5% and 92.9%, respectively.

CONCLUSIONS

Rapid on-site evaluation during EBUS with a guide sheath has a high diagnostic value for malignant PPLs.

Utility of Endobronchial Ultrasound in Assessment of Intrathoracic Lesions in Paediatric Patients

INTRODUCTION

In adults, linear endobronchial ultrasound (EBUS) is the preferred modality to sample intrathoracic adenopathy and radial EBUS is a useful tool to biopsy peripheral pulmonary nodules. Utility in children is less well known.

OBJECTIVES

The objective of this study was to review the EBUS experience of two specialist centres to better define the current role of EBUS in paediatric practice.

METHODS

A retrospective record review of EBUS procedures undertaken in patients aged 0-17 years at the Royal Children's Hospital (Melbourne, Australia) and Thoraxklinik (Heidelberg, Germany) was performed. Data extracted included patient demographics, clinical presentation, bronchoscope (size and model), EBUS technique used, pathologic results, need for further invasive investigation, and complications.

RESULTS

Between 2008 and 2017, ten EBUS procedures were performed (6 linear EBUS and 4 radial EBUS). No complications were reported. Linear EBUS was performed on subjects who were between 4 and 15 years old, with a 100% diagnostic yield. Radial EBUS was non-diagnostic in three cases of non-malignant disease. In one case, it was used successfully for imaging alone.

CONCLUSION

Both linear and radial EBUS are safe and feasible in children. Diagnostic yield of linear EBUS was 100%. Radial EBUS did not demonstrate utility, likely reflecting the pathologies of underlying parenchymal masses in paediatric populations.

Novel multiplex droplet digital PCR assay for scoring PD-L1 in non-small cell lung cancer biopsy specimens

OBJECTIVES

Immune checkpoint inhibitors have become integrated into the clinical management of non-small cell lung cancer (NSCLC). Using RTqPCR, we have previously identified a gene expression panel that detected presence of malignant cells (MMP9:TIMP3 ratio) and quantified PD-L1 transcript levels in small biopsy specimens. However, RTqPCR has diagnostic limitations as it does not generate absolute copy number and is not readily multiplexed. To address this, we have developed a multiplex droplet digital PCR (ddPCR) assay.

MATERIALS AND METHODS

Biopsies obtained from NSCLC patients (n = 48 adenocarcinoma and n = 40 squamous cell carcinoma) and control lung biopsy specimens (n = 20) were analysed. Absolute MMP9, TIMP3 and PD-L1 transcript copy numbers were determined within a single assay by multiplex ddPCR using Taqman primers and the QX200 Droplet Digital PCR System.

RESULTS AND CONCLUSIONS

Using our optimised triplex ddPCR assay, the MMP9:TIMP3 ratio was significantly elevated in NSCLC biopsies and using a cut-off of >0.028, was 99% (95% CI; 80.5-94.5) sensitive and 80% specific for identifying malignant biopsies. The PD-L1:TIMP3 ratio significantly associated with PD-L1 tumour cell immunohistochemistry staining (r = 0.539, p < 0.0001) and was significantly higher in biopsies with >50% PD-L1 tumour cell staining (p < 0.0001). In summary, a major advantage of our workflow is that it can accurately quantify PD-L1 tumour levels and provide sufficient nucleic acid for screening additional targetable mutations such as EGFR, ALK and ROS1 from a single small biopsy, thereby potentially avoiding the need for re-biopsy. Future studies will need to determine diagnostic ddPCR values that are predictive of clinical response to PD-1/PD-L1 immunotherapy.

A combined gene expression tool for parallel histological prediction and gene fusion detection in non-small cell lung cancer

Accurate histological classification and identification of fusion genes represent two cornerstones of clinical diagnostics in non-small cell lung cancer (NSCLC). Here, we present a NanoString gene expression platform and a novel platform-independent, single sample predictor (SSP) of NSCLC histology for combined, simultaneous, histological classification and fusion gene detection in minimal formalin fixed paraffin embedded (FFPE) tissue. The SSP was developed in 68 NSCLC tumors of adenocarcinoma (AC), squamous cell carcinoma (SqCC) and large-cell neuroendocrine carcinoma (LCNEC) histology, based on NanoString expression of 11 (CHGA, SYP, CD56, SFTPG, NAPSA, TTF-1, TP73L, KRT6A, KRT5, KRT40, KRT16) relevant genes for IHC-based NSCLC histology classification. The SSP was combined with a gene fusion detection module (analyzing ALK, RET, ROS1, MET, NRG1, and NTRK1) into a multicomponent NanoString assay. The histological SSP was validated in six cohorts varying in size (n = 11–199), tissue origin (early or advanced disease), histological composition (including undifferentiated cancer), and gene expression platform. Fusion gene detection revealed five EML4-ALK fusions, four KIF5B-RET fusions, two CD74-NRG1 fusion and three MET exon 14 skipping events among 131 tested cases. The histological SSP was successfully trained and tested in the development cohort (mean AUC = 0.96 in iterated test sets). The SSP proved successful in predicting histology of NSCLC tumors of well-defined subgroups and difficult undifferentiated morphology irrespective of gene expression data platform. Discrepancies between gene expression prediction and histologic diagnosis included cases with mixed histologies, true large cell carcinomas, or poorly differentiated adenocarcinomas with mucin expression. In summary, we present a proof-of-concept multicomponent assay for parallel histological classification and multiplexed fusion gene detection in archival tissue, including a novel platform-independent histological SSP classifier. The assay and SSP could serve as a promising complement in the routine evaluation of diagnostic lung cancer biopsies.

Feasibility of lung cancer RNA acquisition from a single transbronchial or transthoracic needle pass (FASTT trial)

INTRODUCTION

RNA isolation from tumor tissue is used for biomarker analyses and validation. Limited diagnostic material from small volume biopsies combined with an increasing demand for standard histologic, molecular characterization, and next generation sequencing applications often leads to limited material for research. We sought to evaluate small volume sampling of lung cancer tissue collected from a single needle pass during a diagnostic procedure and determine if it can provide RNA of acceptable quantity and quality.

METHODS

We enrolled 140 patients with probable primary bronchogenic carcinoma and collected RNA from a dedicated FNA aspiration. Total RNA (ηg), RNA integrity number (RIN), and %Mass in base pairs were evaluated from each patient sample. A customized nanoString nCounter® 95-gene panel was used to profile the expression patterns of feature NSCLC genes. We compared gene expression patterns that distinguish lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) in our cohort with a corresponding Cancer Genome Atlas (TCGA) NSCLC datasets.

RESULTS

Of the 149 patients consented. RNA-extraction was performed in 101 eligible patients. A satisfactory total RNA mass and RIN was quantified for all samples with a similar distribution among cellular subtypes. Mean %-Mass over 300 base pairs was noted for all specimens and 96% of samples met criteria to perform genetic evaluation with our commercialized gene expression assay. The FNA-derived transcriptomic results showed excellent consistency with the TCGA counterparts, and the differential expression pattern of LUAD vs LUSC subtypes were highly similar.

DISCUSSION

In this study, RNA retrieval from a single-pass FNA regardless of procedural approach showed equivalence and suitability for gene expression assessments. RNA extraction from small volume samples has the potential to provide valuable material for genetic profiling.

Pulmonologist-performed transoesophageal sampling for lung cancer staging using an endobronchial ultrasound video-bronchoscope: an Australian experience

BACKGROUND

Transoesophageal endobronchial ultrasound (EBUS) video-bronchoscope insertion provides pulmonologists access to conduct endoscopic fine-needle aspiration (EUS-B-FNA) of mediastinal lymph node (LN) lesions and also assist in lung cancer staging by sampling left adrenal gland (LAG) lesions. Limited literature has described additional diagnostic value whilst maintaining patient safety. To elicit whether combining endoscopic transoesophageal fine-needle aspiration using convex probe bronchoscope (EUS-B-FNA) and EBUS bronchoscopy enhances the diagnostic yield of mediastinal nodal staging in lung cancer, whilst maintaining safety.

METHODS

All eligible patients with paraoesophageal lesions on thoracic computed tomography (CT) underwent pulmonologist-performed EUS-B-FNA at two tertiary centres and were included in this prospective observational cohort study.

RESULTS

EUS-B-FNA sampling was performed at 69 mediastinal LN lesion sites, including 17 sites inaccessible to bronchoscopic sampling. Four LAG lesions were sampled via EUS-B-FNA. There were no complications. EBUS-TBNA was augmented by EUS-B-FNA because of accessibility of sampling lesions otherwise unamenable bronchoscopically, thereby increasing diagnostic utility. Diagnostic sensitivity of EUS-B-FNA for malignancy in mediastinal LN lesions was 88% (51 of 58). For mediastinal LN lesions not amenable to EBUS-TBNA, the sensitivity for diagnosis of malignancy via EUS-B-FNA was 88% (15 of 17). Diagnostic sensitivity of EUS-B-FNA for malignancy in LAG lesions was 50% (2 of 4).

CONCLUSION

EUS-B-FNA is a precise and safe approach in the evaluation and staging of lung cancer when performed by a pulmonologist. It complements and increases the diagnostic utility of EBUS-TBNA by further coverage of mediastinal LN stations and access to LAG lesions.

Endobronchial ultrasound guided transbronchial needle aspiration combining with immunohistochemistry and genotype in lung cancer: A single-center, 55 cases retrospective study

OBJECTIVE

The purpose of this study was to evaluate the utility of EBUS-TNA for mediastinal mass or suspected lung cancer patients with mediastinal or hilar lymph node enlarged. Further to investigate the clinical value of EBUS-TBNA combining with immunohistochemistry and genotype in lung cancer.

METHODS

A total of 55 patients with mediastinal, and/or hilar lymphadenopathy, and/or mediastinal mass previously detected by CT or PET/CT scan and who underwent EBUS-TBNA. An additional immunohistological analysis was performed for establishing a reliable diagnosis and sub classification when necessary. Some samples were tested for the EGFR and/or ALK mutations to provide suitable mutational genotyping for adenocarcinoma by using the PCR assays.

RESULTS

Of the 55 patients, the sensitivity and diagnostic accuracy of EBUS-TBNA in the diagnosis of lung cancer were 92.5% (37/40) and 94.5% (52/55), respectively. 37 samples were further confirmed and obtained particular type by Immunohistochemistry. 6 cases of EBUS-TBNA samples from patients with lung adenocarcinoma referred for EGFR testing were analyzed, 4 patients were found to have EGFR gene mutations. The procedure was uneventful without any complications.

CONCLUSION

EBUS-TBNA is a safe and efficient method with high sensitivity and specificity in the diagnosis of lung cancer. Uniquely combining with Immunohistochemistry and molecular testing has significant clinical value in subtype diagnosis and guiding the treatment strategy in lung cancer.

Pulmonologist-Performed Per-Esophageal Needle Aspiration of Parenchymal Lung Lesions Using an EBUS Bronchoscope: Diagnostic Utility and Safety

BACKGROUND

Transesophageal introduction of the endobronchial ultrasound (EBUS) videobronchoscope allows pulmonologists to perform endoscopic ultrasound fine-needle aspiration (EUS-B-FNA) of mediastinal lesions. Safety, diagnostic accuracy, and feasibility of EUS-B-FNA in evaluation of pulmonary parenchymal lesions are not established.

METHODS

All patients undergoing pulmonologist-performed EUS-B-FNA of parenchymal lung lesions at 2 tertiary centers were included in this prospective observational cohort study.

RESULTS

EUS-B-FNA sampling of parenchymal lesions was performed in 27 patients. Mean (±SD) lesion size was 36±16 mm. Seven lesions were ≤18 mm. Pneumothorax occurred in 1 patient (3.7%, 95% confidence interval, 0.001%-19%). Ten target lesions (36%) were in locations inaccessible to bronchoscopic sampling via the airways, and 9 lesions were inaccessible to EBUS-guided transbronchial needle aspiration and in locations associated with low diagnostic yield from radial EBUS. EUS-B-FNA was diagnostic in 26 patients (96%), and sensitivity of EUS-B-FNA was 100% (95% confidence interval, 87%-100%) for both lung cancer (n=21) and for pulmonary metastatic lesions (n=5).

CONCLUSIONS

Pulmonologist-performed EUS-B-FNA is safe and accurate in the evaluation parenchymal lung lesions. Diagnostic accuracy is high. EUS-B-FNA may achieve access to sites not amenable to other forms of bronchoscopic sampling, or increase diagnostic accuracy in patients where anatomic position predicts a low diagnostic yield.

Comparison of multiple techniques for endobronchial ultrasound-transbronchial needle aspiration specimen preparation in a single institution experience

BACKGROUND

The optimal method for specimen preparation of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) is still controversial. This study aims to compare several techniques available for EBUS-TBNA specimen acquisition and processing, in order to identify the best performing technique.

METHODS

We retrospectively reviewed the data of 199 consecutive patients [male, 73%; median age, 64 years (IQR: 52-74 years)] undergoing EBUS-TBNA at our institution from 2012 through 2014 for diagnosis of hilar-mediastinal lymph node enlargement suspect of neoplastic (n=139) or granulomatous (n=60) disease. All procedures were performed by two experienced bronchoscopists, under conscious sedation and local anaesthesia, using 21/22-Gauge (G) needle, without rapid on-site evaluation (ROSE). Five specimen-processing techniques were used: cytology slides in 42 cases (21%); cell-block in 25 (13%); core-tissue in 60 (30%); combination of cytology slides and core-tissue in 51 (26%); combination of cytology slides and cell-block in 21 (10%). To assess the diagnostic accuracy of each tissue-processing technique we compared the EBUS-TBNA results to those obtained with surgical lymphadenectomy, or 1-year follow-up in non-operated patients.

RESULTS

Diagnostic yield, accuracy and area under the curve (AUC) were as follows. Cytology slides: 81%, 80%, 0.90; cell-block: 48%, 33%, 0.67; core-tissue: 87%, 99%, 0.96; cytology slides + core-tissue: 80%, 100%, 1.00; cytology slides + cell-block: 86%, 100%, 1.00. Cytology slides and core-tissue method showed non-significantly different diagnostic yield (P=0.435) and AUC (P=0.152).

CONCLUSIONS

In our single-institution experience, cytology slides and core-tissue preparations demonstrated high and similar diagnostic performance. Cytology slides combination with core-tissue or cell-block showed the highest performance, however these combination methods were more resource-consuming.

Endobronchial ultrasound-transbronchial needle aspiration for mediastinal staging of non-small cell lung cancer: variability of results and perspectives

The remarkable value of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) for mediastinal staging of non-small cell lung cancer (NSCLC) is recognized worldwide. Reports from different centers however show considerable variation of EBUS-TBNA performance in terms of diagnostic yield, sensitivity and negative predictive value (NPV). Interpretation of EBUS-TBNA diagnostic efficacy requires clarifying whether the technique is used for purely diagnostic purpose or mediastinal staging, recognizing that different study groups may be inherently heterogeneous and that numerous factors may impact on the procedure outcomes. Review of these factors indicates that the prevalence of N2/N3 disease, the thoroughness of mediastinal sampling and >3 needle passes per target lymph node (LN) [in the absence of rapid on-site evaluation (ROSE)] influence the procedure outcomes, while many details in the sample preparation technique are unlikely to impact on the results and should be left to the proceduralists' preference. Generalized use of a standardized database for prospective collection of relevant EBUS-TBNA data would allow reporting institutional results by sub-groups of N2/N3 disease prevalence and thoroughness of staging, and would help establishing quality standards for the procedure.

Systematic Endobronchial Ultrasound-guided Mediastinal Staging Versus Positron Emission Tomography for Comprehensive Mediastinal Staging in NSCLC Before Radical Radiotherapy of Non-small Cell Lung Cancer: A Pilot Study

Despite known limitations of positron emission tomography (PET) for mediastinal staging of non-small cell lung cancer (NSCLC), radiation treatment fields are generally based on PET-identified disease extent. However, no studies have examined the accuracy of FDG-PET/CT on a per-node basis in patients being considered for curative-intent radiotherapy in NSCLC.In a prospective trial, patients with NSCLC being considered for definitive thoracic radiotherapy (± systemic chemotherapy) underwent minimally invasive systematic mediastinal evaluation with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) following noninvasive staging with integrated PET-CT.Thirty patients underwent EBUS-TBNA, with TBNA performed from a mean 2.5 lymph node (LN) stations per patient (median 3, range 1-5). Discordant findings between PET-CT and EBUS-TBNA were observed in 10 patients (33%, 95% CI 19%-51%). PET-occult LN metastases were demonstrated by EBUS in 4 patients, whereas a lesser extent of mediastinal involvement, compared with FDG-PET, was demonstrated by EBUS in 6 patients, including 2 patients downstaged from cN3 to pN2. LNs upstaged by EBUS were significantly smaller than nodes downstaged by EBUS, 7.5 mm (range 7-9) versus 12 mm (range 6-21), P = 0.005.A significant proportion of patients considered for definitive radiotherapy (+/-chemotherapy) undergoing systematic mediastinal evaluation with EBUS-TBNA in this study have an extent of mediastinal NSCLC involvement discordant with that indicated by PET-CT. Systematic EBUS-TBNA may aid in defining the extent of mediastinal involvement in NSCLC patients undergoing radiotherapy. Systematic EBUS-TBNA has the potential to contribute significantly to radiotherapy planning and delivery, by either identifying occult nodal metastases, or demonstrating FDG-avid LNs to be disease-free.

Transbronchial Catheter Aspiration and Transbronchial Needle Aspiration in the Diagnostic Workup of Peripheral Lung Lesions

PURPOSE

Increasingly frequent, it is clinically indicated to obtain tissue from a peripheral lung lesion (PLL) to yield a pathological diagnosis. The aim of the present study was to evaluate the diagnostic sensitivity of transbronchial needle aspiration (TBNA) and transbronchial catheter aspiration (TBCA) in addition to transbronchial forceps biopsy (TBB) at conventional bronchoscopy.

METHODS

Eligible patients showing a PLL on computed tomography scans were included in the study. In all patients, following TBB, TBNA and TBCA were employed in randomised order under fluoroscopy.

RESULTS

Fourty-eight patients were enrolled, of whom 46 patients with 46 PLLs were included in the analysis. The mean ± SD diameter of the PLL was 27.0 ± 13.3 mm. The overall sensitivity for all modalities was 69.6%; PLL ≤20 or >20 and ≤30 mm in diameter showed a sensitivity of 60.0 and 72.2%, respectively. For malignant PLL (n = 33), the combined sensitivity of TBNA + TBCA versus TBB was significantly higher (63.6 vs. 33.3%, p ≤ 0.05), and could not further be improved by TBB. For benign PLL, TBB was superior to TBNA + TBCA (76.9 vs. 38.5%).

CONCLUSIONS

TBB, TBNA and TBCA are complementary to one another. Combining the three techniques, even allows transbronchial specimen collection of PLL <3 cm in diameter at conventional bronchoscopy.

Utility of EBUS-TBNA for diagnosis of mediastinal tuberculous lymphadenitis: a multicentre Australian experience

BACKGROUND

Endobronchial ultrasound (EBUS) transbronchial needle aspiration (TBNA) is an important diagnostic procedure for the interrogation of mediastinal lymph nodes. There is limited data describing the accuracy & safety of this technique for the diagnosis of tuberculous mediastinal lymphadenitis.

METHODS

A multi-centre retrospective study of all EBUS-guided TBNA procedures that referred samples for mycobacteriology was performed. Results were correlated with post-procedural diagnoses after a period of surveillance and cross-checked against relevant statewide tuberculosis (TB) registries, and sensitivity and specificity was calculated. In addition, nucleic acid amplification techniques (NAAT) were assessed, and sensitivity and specificity calculated using positive mycobacterial culture as the reference gold standard.

RESULTS

One hundred and fifty-nine patients underwent EBUS-TBNA and had tissue referred for mycobacterial culture, of which 158 were included in the final analysis. Thirty-nine were ultimately diagnosed with TB (25%). Sensitivity of EBUS-TBNA for microbiologically confirmed tuberculous mediastinal lymphadenitis was 62% (24/39 cases). Specificity was 100%. Negative predictive value (NPV) and diagnostic accuracy for microbiologic diagnosis was 89% [95% confidence intervals (CI), 82-93%] and 91% (95% CI, 84-94%) respectively. For a composite clinicopathologic diagnosis of TB NPV and accuracy were 98% (95% CI, 93-99%) and 98% (95% CI, 95-99%) respectively. Sensitivity for NAAT was 38% (95% CI, 18-65%).

CONCLUSIONS

EBUS-TBNA is a safe and well tolerated procedure in the assessment of patients with suspected isolated mediastinal lymphadenitis and demonstrates good sensitivity for a microbiologic diagnosis of isolated mediastinal lymphadenitis. When culture and histological results are combined with high clinical suspicion, EBUS-TBNA demonstrates excellent diagnostic accuracy and NPV for the diagnosis of mediastinal TB lymphadenitis. We suggest EBUS-TBNA should be considered the procedure of choice for patients in whom TB is suspected.

Endobronchial ultrasound-guided transbronchial needle aspiration in lung cancer diagnosis and staging

Lung cancer is one of the most prevalent types of cancer in the world. A complete diagnosis of lung cancer involves tissue acquisition for pathological subtype, molecular diagnosis and accurate staging of the disease to guide appropriate therapy. Real-time endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is minimally invasive and relatively safe procedure, which can be done on an outpatient basis under moderate sedation. EBUS-TBNA has been shown to be a safe modality to obtain tissue for diagnosis, staging and molecular profiling in lung cancer. EBUS-TBNA stands out in comparison with other modalities for tissue acquisition in lung cancer. EBUS-TBNA performed with the patient under moderate sedation yields sufficient tissue for sequential molecular analysis in most patients. In this review, we describe the role of EBUS-TBNA in various aspects of diagnosis and staging of lung cancer in the present era along with its future aspects.

Guideline for the acquisition and preparation of conventional and endobronchial ultrasound-guided transbronchial needle aspiration specimens for the diagnosis and molecular testing of patients with known or suspected lung cancer

RATIONALE

Conventional transbronchial needle aspiration (TBNA) and endobronchial ultrasound (EBUS)-TBNA are widely accepted tools for the diagnosis and staging of lung cancer and the initial procedure of choice for staging. Obtaining adequate specimens is key to provide a specific histologic and molecular diagnosis of lung cancer.

OBJECTIVES

To develop practice guidelines on the acquisition and preparation of conventional TBNA and EBUS-TBNA specimens for the diagnosis and molecular testing of (suspected) lung cancer. We hope to improve the global unification of procedure standards, maximize the yield and identify areas for research.

METHODS

Systematic electronic database searches were conducted to identify relevant studies for inclusion in the guideline [PubMed and the Cochrane Library (including the Cochrane Database of Systematic Reviews)].

MAIN RESULTS

The number of needle aspirations with both conventional TBNA and EBUS-TBNA was found to impact the diagnostic yield, with at least 3 passes needed for optimal performance. Neither needle gauge nor the use of miniforceps, the use of suction or the type of sedation/anesthesia has been found to improve the diagnostic yield for lung cancer. The use of rapid on-site cytology examination does not increase the diagnostic yield. Molecular analysis (i.e. EGFR, KRAS and ALK) can be routinely performed on the majority of cytological samples obtained by EBUS-TBNA and conventional TBNA. There does not appear to be a superior method for specimen preparation (i.e. slide staining, cell blocks or core tissue). It is likely that optimal specimen preparation may vary between institutions depending on the expertise of pathology colleagues.

Novel agents in development for advanced non-small cell lung cancer

The identification of EGFR mutations and ALK rearrangements in nonsmall cell lung cancer (NSCLC) has led to the rapid development of targeted therapies and significant changes in the treatment paradigm. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and crizotinib are now standard therapies for patients with the appropriate molecular alteration. Current investigations are determining the mechanisms of resistance to targeted therapies and developing novel agents to combat resistance. For patients with KRAS mutant NSCLC, a phase III trial of the MEK inhibitor, selumetinib, has been initiated. For patients without a defined mutation or a mutation without a known targeted therapy, immunotherapy, ganetespib, nintedanib and MET inhibitors in combination with EGFR TKIs are in development. Preliminary results of phase III trials raise doubts about the future development of dacomitinib as a second-line agent.

The cryo-needle: a new tool for histological biopsies. A feasibility study

PURPOSE

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a standard procedure for intrathoracic lymph node biopsies. The newly developed cryo-needle operates in a similar way to the EBUS-TBNA but is able to obtain specimens for histological evaluation. The purpose of this animal study was to evaluate the feasibility, effect, and safety of the cryo-needle biopsies.

METHODS

Four EBUS-guided cryo-needle biopsies were obtained from a mediastinal lymph node of a healthy pig. In an open surgery approach, cryo-needle biopsies using activation times of 1, 2, and 3 s (A1/A2/A3) and needle biopsies using a 21-gauge EBUS-TBNA needle were obtained from mesenteric lymph nodes. Cryo-needle biopsies A2 were performed with (A2+) and without (A2-) an oversheath. The size, weight, percentage of lymphatic tissue and artefact-free area of each cryobiopsy were evaluated. Smears were made with the TBNA-needle aspirates to determine the number of lymphocytes per high-power field (HPF). The bleeding duration was measured.

RESULTS

We successfully obtained EBUS-guided cryo-needle biopsies. The area and weight of the biopsies A3 and A2+ were significantly larger compared with A1 (1.7 ± 0.8 and 1.4 ± 0.3 vs. 0.9 ± 0.4 mm(2); 5.2 ± 2.4 and 3.4 ± 1.8 vs. 1.5 ± 0.7 mg). The percentage of lymphatic tissue of the cryobiopsies was 90 ± 25 and 98 % of samples were artefact-free. The number of lymphocytes/HPF of TBNA-needle smears was 128 ± 54.3. There was no difference in bleeding duration between the techniques.

CONCLUSIONS

The cryo-needle yields large histological specimens of high quality.