Rapid and Highly Sensitive Detection of Therapeutically Relevant Oncogenic Driver Mutations in EBUS-TBNA Specimens From Patients With Lung Adenocarcinoma

Endobronchial ultrasound-guided transbronchial needle aspiration in patients with previously treated malignancies: diagnostic performance and predictive value

BACKGROUND

Endobronchial ultrasound-guided transbronchial needle aspiration is a minimally invasive and effective sampling approach for patients with mediastinal or hilar lymphadenopathy. Increased recognition of the ultrasonographic features revealed the value of its images in predicting mediastinal lymph node malignancy. However, its diagnostic validity and the predictive value of its ultrasonographic features have not been demonstrated well in patients after systemic anti-tumor therapy. This study aimed to evaluate the efficiency of endobronchial ultrasound-guided transbronchial needle aspiration in patients with suspicious lymph nodes after anti-tumor therapy.

METHODS

We retrospectively reviewed cases of endobronchial ultrasound-guided transbronchial needle aspiration performed between January 2019 and August 2021 at a single tertiary hospital center. Patients with suspected mediastinal or hilar lymph nodes within 5 years of systemic anti-tumor therapy were enrolled. Final diagnoses were determined by pathologic diagnoses of samples from transbronchial needle aspiration, surgery, or follow-up for at least 6 months. Ultrasonographic features were analyzed to assess the predictive value of malignant lymph nodes after treatment.

RESULTS

Overall, 168 lymph nodes of 138 patients were analyzed. Among 110 (65.5%) malignant lymph nodes, 75 originated from lung cancers; the other 35 were from other malignancies. No complications related to endobronchial ultrasound-guided transbronchial needle aspiration were observed. Of 58 negative results of transbronchial needle aspiration, 51 were proven to be true negatives; 7 were false. The overall sensitivity and the negative predictive value were 94.02% and 87.93%, respectively. Univariate and multivariate analysis revealed the absence of central hilar structure and short axis > 10 mm as independent predictive factors for malignancy.

CONCLUSIONS

Endobronchial ultrasound-guided transbronchial needle aspiration performs satisfactorily in diagnosing mediastinal and hilar lymphadenopathy even after anti-tumor treatment.

Crown-Cut Endobronchial Ultrasound Guided Transbronchial Aspiration Needle: First Real-World Experiences

Advancements in personalized medicine have increased the demand for quantity and preservation of tissue architecture of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples. These demands may be addressed by the SonoTip TopGain^® needle, which has a 3-point crown-cut design that contrasts with the standard single bevel design of the ViziShot 2^®. The objective was to compare the SonoTip TopGain^® and ViziShot 2^® needles by considering biopsy sample characteristics, diagnostic accuracy, and patient safety. The primary endpoint of the study was the number of high-power fields (HPFs) in the center of the formalin-fixed paraffin-embedded cell block per sample. The lymph node with the highest probability for malignant infiltration based on size and sonographic appearance was chosen as the target lymph node for 20 patients. The same lymph node in each patient was sampled using both the ViziShot 2^® and SonoTip TopGain^® needles. The samples were measured, sliced, and analyzed by a pathologist. Sixteen patients were biopsied with both needles. Four patients could not be biopsied with the SonoTip TopGain^® needle since it could not penetrate cartilage or be repositioned to bypass cartilage. HPFs and sample dimensions were significantly greater in the patients where sampling with the SonoTip TopGain^® needle was possible (p = 0.007 and p = 0.005, respectively). Diagnostic accuracy and safety profiles were comparable. Significantly more material can be sampled using the SonoTip TopGain^® needle when cartilage penetration can be avoided. This improves the yield for molecular workup in the era of personalized medicine.

Linear Endobronchial Ultrasound in the Era of Personalized Lung Cancer Diagnostics-A Technical Review

Major advances in molecular profiling for available targeted treatments and immunotherapy for lung cancer have significantly increased the complexity of tissue-based diagnostics. Endobronchial ultrasound-guided transbronchial needle aspirations (EBUS-TBNA) are commonly performed for diagnostic biopsies and lymph node staging. EBUS-TBNA has increasingly become one of the main sources of tumor cells for molecular analyses. As a result, there is a growing need for high quality EBUS-TBNA samples with adequate cellularity. This has increased the technical demands of the procedure and has created additional challenges, many of which are not addressed in the current EBUS guidelines. This review provides an overview of current evidence on the technical aspects of EBUS-TBNA in light of comprehensive sample processing for personalized lung cancer management. These include sonographic lymph node characterization, optimal needle choice, suction biopsy technique, and the role of rapid on-site evaluation. Attention to these technical details will be important to maximize the throughput of EBUS-TBNA biopsies for molecular testing.

The Impact of Core Tissues on Successful Next-Generation Sequencing Analysis of Specimens Obtained through Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration

The success rate of next-generation sequencing (NGS) with specimens obtained through endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) among patients with lung cancer as well as the related clinical factors remain unclear. We aimed to determine the optimal number of punctures and core tissues during EBUS-TBNA for NGS in patients with non-small-cell lung cancer (NSCLC) as well as the association of chest computed tomography (CT) and EBUS findings with successful NGS. We retrospectively reviewed 156 consecutive patients with NSCLC who underwent EBUS-TBNA for NGS (Oncomine^TM Dx Target Test). Using the receiver operating characteristic curve, we calculated the optimal numbers of punctures and core tissues for NGS and evaluated CT and EBUS findings suggestive of necrosis and vascular pattern within the lesion. The success rate of NGS was 83.3%. The cut-off value for the number of core tissues was 4, and the sensitivity and specificity of successful NGS were 73.8% and 61.5%, respectively. Logistic regression analysis revealed that the number of core tissues (≥4) was the sole predictor of successful NGS. CT and EBUS findings were not associated with successful NGS. Bronchoscopists should obtain sufficient core tissues for successful NGS using EBUS-TBNA specimens.

Rapid onsite evaluation uses a very small proportion of total material aspirated at endobronchial or endoscopic ultrasound in the investigation of suspected thoracic malignancy

INTRODUCTION

The objectives were: to measure the proportion of aspirated material used to make direct slides for rapid onsite evaluation (ROSE) at endobronchial (EBUS) and endoscopic ultrasound (EUS) in suspected thoracic malignancy; and to correlate pass weights with ROSE category and needle size.

METHOD

All EBUS and EUS cases for possible thoracic malignancy October 2018-May 2019 were included. All material from each pass was expelled into a Petri dish. One drop of material was placed on each of two slides; one used for ROSE, the other fixed and remaining material processed to cell block. Dish and slides were weighed before and after this procedure on a sensitive balance and weight of aspirate and slide material calculated. When ROSE identified malignancy, slide production ceased but target sampling for ancillary studies continued.

RESULTS

ROSE accuracy was 96.8%. Mean percentage by target of aspirated material used to make direct slides for ROSE was 1.9% in malignant cases and 3.6% in non-malignant cases (P = .027 for difference). Mean percentage by pass was 5.9%. Mean weight of a single aspirate was 128.8 mg. Mean weight of aspirates insufficient on ROSE (175.7 mg) was significantly higher than the mean weight of benign or malignant aspirates (117.1 and 114.0 mg, respectively). Mean weight of aspirates using 22G needles (132.6 mg) was significantly higher than that for 25G needles (87.1 mg).

CONCLUSION

Material made into direct slides at EBUS and EUS and used in part for ROSE uses a tiny proportion of aspirated material with over 98% processed to cell block and available for ancillary testing in malignant cases.

Comparison of adequacy between transbronchial lung cryobiopsy samples and endobronchial ultrasound-guided transbronchial needle aspiration samples for next-generation sequencing analysis

Background

Most lung cancer patients present with lesions in both lung fields and lymphadenopathy. Thus, transbronchial lung cryobiopsy (TBLC) and endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) are commonly performed for diagnosing lung cancer. However, the adequacy of these samples for next‐generation sequencing (NGS) analysis remains unclear. This study aimed to compare the adequacy between TBLC and EBUS‐TBNA samples for NGS analysis.

Methods

This retrospective cohort study included patients whose lung samples were collected via TBLC or EBUS‐TBNA and analyzed using NGS. Out of 46 genes, the number of genes in TBNA and TBLC samples that could not be assessed via NGS analysis was mainly evaluated.

Results

A total of 37 patients were included and classified into two groups (TBLC group, n = 18 and TBNA group, n = 19). The mean number of genes that could not be evaluated via NGS analysis was significantly lower in the TBLC group than in the TBNA group (0.9 vs. 10.3, P = 0.024). The median total area of tumor cells in TBLC samples was significantly greater than that in TBNA samples (6.3 [1.6–4.2] vs. 2.6 [0.2–17.3] mm², P < 0.01). In the TBNA group, there were two fully inadequate samples for NGS analysis with a high degree of cell crush or low tumor content, while there was no fully inadequate sample in the TBLC group.

Conclusions

TBLC is more effective in obtaining adequate samples for NGS analysis than EBUS‐TBNA. TBLC should be performed to obtain adequate samples for NGS analysis in lung cancer patients with target lesions in lung fields, even if they have lymphadenopathy.

Key points

Significant findings of the study

The mean number of genes that could not be evaluated was significantly lower in TBLC samples than in EBUS‐TBNA samples (0.9 vs. 10.3, P = 0.024). TBLC could obtain adequate samples with a high concentration of uncrushed tumor cells for NGS.

What this study adds

To obtain samples for NGS analysis, the use of TBLC should be aggressively considered in lung‐cancer patients with target lesions located in lung fields, even if they have lymphadenopathy.

Improvement strategies for successful next-generation sequencing analysis of lung cancer

Aim: We aimed to improve the success rate of NGS (next-generation sequencing) analysis through improved strategies of lung cancer sampling. Materials & methods: The improvement strategies are as follows. Surgically resected specimens were preferentially submitted in cooperation with pathologists and surgeons. In bronchoscopic samples, the size of the sample collection device and the number of samples collected was increased. Results: The strategies increased the success rate of NGS analysis of DNA from 69.3 to 91.1%, and that of RNA from 64.6 to 90.0%. Discussion: The introduction of strategies aimed at improving the success of NGS analysis resulted in an improvement in the success rate and brought us closer to the delivery of effective precision medicine in cancer therapy.