Assessment of endobronchial ultrasound-guided bronchoscopy (EBUS) intranodal forceps biopsy added to EBUS 19-gauge transbronchial needle aspiration: A blinded pathology panel analysis.

BACKGROUND: Endobronchial ultrasound-guided (EBUS) transbronchial needle aspiration (TBNA) has significantly improved the diagnostic workup for intrathoracic lymphadenopathies. More recently, EBUS intranodal forceps biopsy (IFB) has been developed in an attempt to maximize diagnostic yield by providing additional tissue. In this study, we aimed to assess the improvement of diagnostic yield with EBUS-TBNA combined with EBUS-IFB, compared to EBUS-TBNA alone. METHODS: Consecutive patients who had 19-G EBUS-TBNA and EBUS-IFB from August 30, 2018, to September 28, 2021, were included. Four senior pathologists retrospectively analyzed, independently and blindly, first, only the EBUS-TBNA samples (cell block), then, at least 1 month later, both samples from EBUS-TBNA and from EBUS-IFB together. RESULTS: Fifty patients were included in the study and 52 lymph nodes were analyzed. Diagnostic yield was 77% (40/52) for EBUS-TBNA alone and 94% (49/52) when combined with EBUS-IFB (p = 0.023). Malignancy was diagnosed with EBUS-TBNA combined with EBUS-IFB in 25/26 cases (96%), versus 22/26 (85%) with EBUS-TBNA alone (p = 0.35); and 4/5 (80%) versus 2/5 (40%) for lymphoma specifically. Kappa interobserver agreement was 0.92 for EBUS-IFB and 0.87 for EBUS-TBNA alone. Nonmalignant condition was diagnosed with EBUS-TBNA combined with EBUS-IFB in 24/26 cases (92%), versus 18/26 (69%) for EBUS-TBNA alone (p = 0.07). CONCLUSION: The use of EBUS-IFB combined with 19-G EBUS-TBNA improves the mediastinal lymph node diagnostic yield However the benefit appears to be mainly restricted to nonmalignant histology.

Ultrafast Gene Fusion Assessment for Nonsquamous NSCLC.

Introduction: Gene fusion testing of ALK, ROS1, RET, NTRK, and MET exon 14 skipping mutations is guideline recommended in nonsquamous NSCLC (NS-NSCLC). Nevertheless, assessment is often hindered by the limited availability of tissue and prolonged next-generation sequencing (NGS) testing, which can protract the initiation of a targeted therapy. Therefore, the development of faster gene fusion assessment is critical for optimal clinical decision-making. Here, we compared two ultrafast gene fusion assays (UFGFAs) using NGS (Genexus, Oncomine Precision Assay, Thermo Fisher Scientific) and a multiplex reverse-transcriptase polymerase chain reaction (Idylla, GeneFusion Assay, Biocartis) approach at diagnosis in a retrospective series of 195 NS-NSCLC cases and five extrapulmonary tumors with a known NTRK fusion. Methods: A total of 195 NS-NSCLC cases (113 known gene fusions and 82 wild-type tumors) were included retrospectively. To validate the detection of a NTRK fusion, we added five NTRK-positive extrathoracic tumors. The diagnostic performance of the two UFGFAs and standard procedures was compared. Results: The accuracy was 92.3% and 93.1% for Idylla and Genexus, respectively. Both systems improved the sensitivity for detection by including a 5'-3' imbalance analysis. Although detection of ROS1, MET exon 14 skipping, and RET was excellent with both systems, ALK fusion detection was reduced with sensitivities of 87% and 88%, respectively. Idylla had a limited sensitivity of 67% for NTRK fusions, in which only an imbalance assessment was used. Conclusions: UFGFA using NGS and reverse-transcriptase polymerase chain reaction approaches had an equal level of detection of gene fusion but with some technique-specific limitations. Nevertheless, UFGFA detection in routine clinical care is feasible with both systems allowing faster initiation of therapy and a broad degree of screening.

Assessment of Per-Endoscopic Placement of Fiducial Gold Markers for Small Peripheral Lung Nodules < 20 mm Before Stereotactic Radiation Therapy.

BACKGROUND: Stereotactic radiotherapy is used to treat peripheral lung cancer in inoperable patients. Placement of fiducial gold markers (FMs) is crucial for tracking small lesions that are not visible on chest radiographs. Our objective was to assess endoscopic FM placement in small peripheral lung nodules (PLNs) that are not trackable using automated tracking software. METHODS: All patients benefiting from virtual bronchoscopy and radial endobronchial ultrasonography (R-EBUS)-guided placement of FMs for PLNs < 20 mm were included. After confirmation by biopsy sampling, a gold-seed FM was inserted into the nodule using a bronchial brush, without the use of fluoroscopy. The performance and complications of the procedure were recorded. RESULTS: From May 2010 to June 2015, FMs were placed in the PLNs of 54 consecutive patients, 34 of whom presented with a nodule < 20 mm. Seventy-six percent of the procedures were performed using local anesthesia on an outpatient basis. The median long- and short-axis diameters of nodules were 15 mm (9-20 mm) and 11 mm (6-20 mm), respectively, with 31 of 34 nodules exhibiting a short axis of < 15 mm. In 23 cases (79%), histologic samples were obtained during the procedure that allowed FM placement. Migration occurred in six cases, including two in the hours following the procedure. FMs were in place and visible on CT imaging performed 3 months after radiation therapy in 80% of cases. No complications were reported. CONCLUSIONS: Diagnosis of peripheral nodules < 20 mm and FM placement using R-EBUS are efficient and safe in a single procedure.

Ligation-dependent RT-PCR: a new specific and low-cost technique to detect ALK, ROS, and RET rearrangements in lung adenocarcinoma.

Detection of anaplastic lymphoma kinase (ALK), ROS proto-oncogene 1 (ROS1), and rearranged during transfection (RET) gene rearrangements in lung adenocarcinoma is usually performed by immunohistochemistry (IHC) screening followed by fluorescence in situ hybridization (FISH), which is an expensive and difficult technique. Ligation-dependent reverse transcription polymerase chain reaction (RT-PCR) multiplex technique can detect gene rearrangements using probes specifically hybridized to either side of the break point. PCR products are then sequenced by pyrosequencing or high throughput sequencing in order to identify the two genes involved. The reagent cost is <15 dollars per patient and results are available in 2 days. We have developed a 47-probe LD-RT-PCR kit especially for lung adenocarcinomas. Thirty-nine lung adenocarcinomas were studied: 24 ALK+, 14 ROS1+, and 1 RET+. ALK+ and ROS1+ were IHC+ (D5F3 Ventana for ALK and D4D6 Cell Signaling Technology for ROS1) and all cases were FISH+ (Vysis ALK Breakapart Probe Abbott for ALK, Zytolight SPEC ROS1 Dualcolor Breakapart Probe for ROS1 and Zytolight SPEC RET Dual Color Breakapart for RET); 14 wild type samples were included as negative controls. Using LD-RT-PCR, 15 rearrangements (63%) were detected in the ALK cases (gene partner: EML4 in all cases), 9 rearrangements (64%) in the ROS1 cases (gene partners: CD74 in 8 cases and SLC34A2 in 1 case) and 1 (100%) in the single RET case (gene partner: KIF5B). No rearrangement was found in the 14 negative control cases. Negative cases using LD-RT-PCR could be explained by the fact that some partner genes were not included in our assay and therefore could not be detected. Because it is an affordable, fast, and very simple technique, we propose using LD-RT-PCR when ALK immunostaining is positive. For LD-RT-PCR-negative cases, samples should then be analyzed by FISH.