A Prospective Validation Study of Lung Cancer Gene Panel Testing Using Cytological Specimens

Clinical utility of rapid on-site evaluation of brush cytology during bronchoscopy using endobronchial ultrasound with a guide sheath

Previous studies have shown that rapid on-site evaluation (ROSE) improves the diagnostic yield of bronchoscopy using endobronchial ultrasound with a guide sheath (EBUS-GS) for peripheral pulmonary lesions (PPL). While ROSE of imprint cytology from forceps biopsy has been widely discussed, there are few reports on ROSE of brush cytology. This study investigated the utility of ROSE of brush cytology during bronchoscopy. We retrospectively analyzed data from 214 patients who underwent bronchoscopy with EBUS-GS for PPL. The patients in the ROSE group had significantly higher diagnostic sensitivity through the entire bronchoscopy process than in the non-ROSE group (96.8% vs. 83.3%, P = 0.002). The use of ROSE significantly increased the sensitivity of brush cytology with Papanicolaou staining (92.9% vs. 75.0%, P < 0.001). When ROSE was sequentially repeated on brushing specimens, initially negative ROSE results converted to positive in 79.5% of cases, and the proportion of specimens with high tumor cell counts increased from 42.1 to 69.0%. This study concludes that ROSE of brush cytology improves the diagnostic accuracy of bronchoscopy and enhances specimen quality through repeated brushing.

Molecular analysis of non-small cell lung cancer using a dual-targeted DNA and RNA comprehensive genomic profiling panel

BACKGROUND

Comprehensive cancer genomic profiling tests have recently been used clinically to guide optimal treatment. Currently approved tests use DNA from tissue or plasma samples to analyze a few hundred genes. RNA panels complement DNA panels to detect fusion and exon skipping.

METHODS

Between April 2017 and March 2022, we analyzed non-small cell lung cancer samples using Todai OncoPanel, a matched tumor/normal pair panel targeting both DNA and RNA. Publicly available genomic data was downloaded from the Center for Cancer Genomics and Advanced Therapeutics database on 2022/11/3.

RESULTS

Sixty non-small cell lung cancer (NSCLC) samples were analyzed. With the DNA panel, 32 samples (53%) had TP53 loss-of-function mutations. Among adenocarcinoma, 17 (33%) had EGFR activating mutations, and 6 (12%) had ERBB2 activating mutations. One BRCA1 and one BRCA2 pathogenic germline variant were also detected. With the RNA panel, 11 fusion genes were detected, all in adenocarcinoma. Specifically, EML4-ALK and KIF5B-RET were detected from one sample each, and 9 others were all novel fusions with unknown pathogenicity. In addition, 4 of 60 (7%) NSCLC samples harbored MET exon 14 skipping. Analysis of the Center for Cancer Genomics and Advanced Therapeutics database found 37 MET exon 14 splice site mutations in 1514 NSCLC samples (2%, p = 0.039).

CONCLUSIONS

Analysis of NSCLC with Todai OncoPanel detected many druggable targets. Its RNA panel may detect MET exon 14 skipping with high sensitivity.

Usefulness of endoscopic ultrasound with bronchoscope-guided fine-needle aspiration for next-generation sequencing in patients with non-small cell lung cancer: A comparison with other bronchoscopic techniques

BACKGROUND

Next-generation sequencing (NGS) is essential in treating advanced lung cancer. However, the effectiveness of endoscopic ultrasound with bronchoscope-guided fine-needle aspiration (EUS-B-FNA) in NGS remains unclear. This study examined the usefulness of EUS-B-FNA in lung cancer NGS cases where EUS-B-FNA was performed for specimen submission in a nationwide genomic screening platform (LC-SCRUM-Asia) and compared specimens collected using other bronchoscopy methods (endobronchial ultrasound-guided transbronchial needle aspiration [EBUS-TBNA] and EBUS-guided transbronchial biopsy with a guide sheath [EBUS-GS-TBB]) during the same period.

METHODS

We retrospectively compared the NGS success rates of NGS, DNA and RNA yields for EUS-B-FNA, EBUS-TBNA, and EBUS-GS-TBB from the records of the patients recruited for the Lung Cancer Genomic Screening Project for Individualized Medicine (LC-SCRUM)-Asia.

RESULTS

Fifty-one patients were enrolled, and the NGS success rates were comparable for samples obtained by EUS-B-FNA, EBUS-TBNA, and EBUS-GS-TBB (100%, 90.9%, and 81.0%, respectively). Genetic alterations were detected in 73.7%, 90.9%, and 85.7% of patients, respectively, with druggable genetic alterations found in 31.6%, 72.7%, and 61.9% of patients, respectively. The DNA and RNA yields were significantly higher in EUS-B-FNA samples than in EBUS-GS-TBB samples (50.4 (interquartile range (IR): 15.45-72.35) ng/μl and 33.9 (IR: 9-76.8) ng/μl from EUS-B-FNA, and 3.3 (IR: 1.4-7.1) ng/μl and 15.1 (IR: 8.3-31.5) ng/μl from EBUS-GS-TBB, respectively, p < 0.05).

CONCLUSION

EUS-B-FNA emerges as a promising bronchoscopic method for obtaining adequate samples for NGS in advanced lung cancer cases.

High-efficiency EGFR genotyping using cell-free DNA in bronchial washing fluid

BACKGROUND

EGFR mutation testing is required for treatment of lung adenocarcinoma using epidermal growth factor receptor-tyrosine kinase inhibitor. However, the amounts of tumor tissue or tumor cells obtained by bronchoscopy are often insufficient. Bronchial washing fluid, obtained by lavage with saline after tumor biopsy or brushing, and the supernatant of bronchial washing fluid are thought to contain cell-free DNA that would be potentially applicable for EGFR testing.

METHODS

From among patients with suspected adenocarcinoma or non-small cell lung carcinoma diagnosed from biopsy or surgical specimens at the University of Tsukuba Hospital between 2015 and 2019, cell-free DNAs from 80 specimens of supernatant of bronchial washing fluid (50 with EGFR mutation and 30 with wild type EGFR) and 8 blood serum samples were examined for EGFR mutation using droplet digital PCR.

RESULTS

Among the 50 patients harboring EGFR mutation, the rate of positivity for cell-free DNA extracted from supernatant of bronchial washing fluid was 80% (40/50). In nine of the EGFR mutation-positive cases, tumor cells were not detected by either biopsy or cytology, but the mutation was detected in four cases (4/9, 44%). Comparison of the cell-free DNA mutation detection rate between supernatant of bronchial washing fluid and blood serum in six cases showed that mutations were detected from the former in all cases (6/6, 100%), but from the latter in only one case (1/6, 17%).

CONCLUSIONS

Using supernatant of bronchial washing fluid samples, the detection rate of EGFR mutation was high, and EGFR mutations were detectable even when no tumor cells had been detectable by biopsy or cytology. Supernatant of bronchial washing fluid might be an effective sample source for EGFR mutation testing.

The Current Achievements of Multi-Gene Panel Tests in Clinical Settings for Patients with Non-Small-Cell Lung Cancer

Some multi-gene panel tests have been implemented in clinical settings to guide targeted therapy in non-small-cell lung cancer (NSCLC) in Japan. The current performance of multi-gene panel tests under the condition that the Oncomine Dx Target Test (ODxTT) and Amoy Dx® Pan Lung Cancer PCR panel (AmoyDx-multi) are available remains relatively unknown. We retrospectively reviewed consecutive patients with NSCLC, whose FFPE samples were considered for genetic testing. We assessed the submission rates, the success rates, and the driver oncogene detection rates of multi-gene panel tests. A total of 225 patients were histologically newly diagnosed with NSCLC or diagnosed with a recurrence of NSCLC without a previous multi-gene panel test at our institution. Among the 225 patients, the FFPE samples of 212 patients (94.2%) were submitted for multi-gene panel testing, including 191 samples (84.9%) for the ODxTT and 21 samples (9.3%) for the AmoyDx-multi. Among the 212 samples submitted to multi-gene panel tests, the success rate was 99.5% (211/212). The detection rate of driver oncogene alterations for all histologies was 52.4% (111/212), and that for adenocarcinoma was 69.7% (106/152). A favorable submission rate and success rate of multi-gene panel tests were shown, along with a favorable detection rate in recent clinical settings.

Utility of bronchoscopically obtained frozen cytology pellets for next-generation sequencing

BACKGROUND

Next-generation sequencing (NGS) is essential for lung cancer treatment. It is important to collect sufficient tissue specimens, but sometimes we cannot obtain large enough samples for NGS analysis. We investigated the yield of NGS analysis by frozen cytology pellets using an Oncomine Comprehensive Assay or Oncomine Precision Assay.

METHODS

We retrospectively enrolled patients with lung cancer who underwent bronchoscopy at Kobe University Hospital and were enrolled in the Lung Cancer Genomic Screening Project for Individualized Medicine. We investigated the amount of extracted DNA and RNA and determined the NGS success rates. We also compared the amount of DNA and RNA by bronchoscopy methods. To create the frozen cytology pellets, we first effectively collected the cells and then quickly centrifuged and cryopreserved them.

RESULTS

A total of 132 patients were enrolled in this study between May 2016 and December 2022; of them, 75 were subjected to frozen cytology pellet examinations and 57 were subjected to frozen tissue examinations. The amount of DNA and RNA obtained by frozen cytology pellets was nearly equivalent to frozen tissues. Frozen cytology pellets collected by endobronchial ultrasound-guided transbronchial needle aspiration yielded significantly more DNA than those collected by transbronchial biopsy methods. (P < 0.01) In RNA content, cytology pellets were not inferior to frozen tissue. The success rate of NGS analysis with frozen cytology pellet specimens was comparable to the success rate of NGS analysis with frozen tissue specimens.

CONCLUSIONS

Our study showed that frozen cytology pellets may have equivalent diagnostic value to frozen tissue for NGS analyses. Bronchial cytology specimens are usually used only for cytology, but NGS analysis is possible if enough cells are collected to create pellet specimens. In particular, the frozen cytology pellets obtained by endobronchial ultrasound-guided transbronchial needle aspiration yielded sufficient amounts of DNA.

TRIAL REGISTRATION

This was registered with the University Medical Hospital Information Network in Japan (UMINCTR registration no. UMIN000052050).

Molecular testing of cytology specimens: Issues in specimen adequacy and clinical utility

BACKGROUND

Next generation sequencing (NGS) is standard of care for workup of many neoplasms including adenocarcinomas of the lung. Molecular testing of cytology samples is used for many types of neoplasms but the value of such testing for the selection of "first"- and "second-line" treatment protocols is incompletely understood.

METHODS

Fifty-six sequentially performed cytology specimens (49 fine needle aspirates and 7 fluids) submitted for molecular analysis were reviewed by a medical oncologist to determine specimen adequacy and utility of results for therapy selection. Chart review was performed to determine availability of microsatellite instability status, tumor mutational burden, and presence of driver mutations treatable with targeted therapy in a "first"- or "second-line" application.

RESULTS

Forty of 56 cases were successfully sequenced and 34% (19/56) had targetable mutations detected by NGS. Ten of these 19 cases (53%) received targeted therapy for their tumor type with five of 10 patients receiving "first-line" therapy and five (50%) "second-line" therapy. Twenty-two mutations were detected where no targeted therapy for the patient's tumor type existed but targeted therapies were available for other tumor types. Of these specimens, only one patient received treatment using protocols associated with a second tumor type. Total mutation burden and microsatellite instability status results were obtained in 29 of 56 cases (52%).

CONCLUSIONS

71% (40/56) of cytologic specimens were adequate for sequencing with 34% (19/56) demonstrating a targetable mutation and 53% of these patients receiving therapy targeted to the driver mutation of their tumor type.

Simulation analysis of EGFR mutation detection: Oncomine Dx target test and AmoyDx panel impact on lung cancer treatment decisions

Lung cancer is a leading cause of cancer-related deaths worldwide. Epidermal growth factor receptor (EGFR) driver mutations are crucial for treatment decisions for patients with non-small cell lung cancer (NSCLC). This study aimed to assess the differences in EGFR mutation detection between two companion diagnostic (CDx) tests-the Oncomine Dx Target Test (ODxTT) and the AmoyDx Pan Lung Cancer PCR Panel-and their impact on treatment applicability. To this end, we used an in-house targeted sequencing dataset of 282 samples from 127 EGFR-mutated NSCLC patients to simulate the concordance between the EGFR variants targeted by the ODxTT and AmoyDx panel, the oncogenicity of the variants, and their therapeutic potential. Of the 216 EGFR mutations identified by the in-house panel, 51% were detectable by both CDx tests, 3% were specific to ODxTT, and 46% were not targeted by either test. Most non-targeted mutations did not have oncogenicity and were located outside exons 18-21. Notably, 95% of the mutations detectable by both tests had potential oncogenicity. Furthermore, among the 96 patients harboring actionable EGFR mutations, 97% had mutations detectable by both CDx tests and 1% by ODxTT, while 2% had mutations not covered by either test. These findings suggest that while both CDx tests are effective in detecting almost all actionable EGFR mutations, ODxTT provides slightly broader coverage. These results emphasize the importance of selecting appropriate CDx tests to inform treatment decisions for EGFR-positive NSCLC patients.

Successful EGFR Mutation Detection in Cytological Specimens of Lung Cancer with Challenging Biopsies by Integrating Virtual Bronchoscopy Navigation and Endobronchial Ultrasound Guidance with Highly Sensitive Next-Generation Sequencing: A Case Report

Introduction

This case report presents the successful detection of an EGFR exon 19 deletion using virtual bronchoscopic navigation (VBN) and endobronchial ultrasound with guide sheath (EBUS-GS) brushing, integrated with highly sensitive next-generation sequencing (NGS), even in challenging biopsy scenarios. The growing prevalence of driver gene alterations in non-small cell lung cancer necessitates effective bronchoscopic technology and reliable multiplex gene NGS panels. However, data regarding the optimal bronchoscopic techniques when using highly sensitive NGS panels are limited. Herein, we report a case utilizing VBN-guided EBUS-GS brushing as an exploratory approach to address this challenge.

Case Presentation

A 71-year-old man was evaluated for a band-like lesion near the left pleura during spinal cord infarction. Transbronchial specimens were obtained from lesions invisible on conventional chest radiography and X-ray fluoroscopy using VBN and EBUS-GS brushing. Cytological brushing specimens revealed lung adenocarcinoma, and highly sensitive NGS identified an EGFR exon 19 deletion. He was diagnosed with stage IB disease and underwent radical radiotherapy owing to his fragile condition. If recurrence occurs, the patient will be treated with an EGFR inhibitor.

Conclusion

VBN-guided EBUS-GS brushing, a minimally invasive approach, combined with highly sensitive NGS has the potential to provide accurate molecular diagnoses to more patients with lung cancer, thereby offering opportunities for personalized treatment. Our findings warrant further investigation to determine optimal bronchoscopic technologies for obtaining tumor specimens.

EML4-ALK Gene Mutation Detected with New NGS Lung Cancer Panel CDx Using Sputum Cytology in a Case of Advanced NSCLC

The detection of driver gene mutations has become essential for lung cancer; however, insufficient sample sizes make gene panel tests difficult to use. We previously reported that the lung cancer compact panel TM (LCCP) could detect EGFR and MET gene mutations with sputum cytology. To date, the detection of gene mutation using RNA from sputum samples is considered practically difficult. We report a case in which the EML4-ALK fusion gene was successfully detected from a sputum sample using the LCCP that was just released in Japan as a new next-generation sequencing lung cancer panel, CDx.

Analytical Performance of a Highly Sensitive System to Detect Gene Variants Using Next-Generation Sequencing for Lung Cancer Companion Diagnostics

The recent increase in the number of molecular targeted agents for lung cancer has led to the demand for the simultaneous testing of multiple genes. Although gene panels using next-generation sequencing (NGS) are ideal, conventional panels require a high tumor content, and biopsy samples often do not meet this requirement. We developed a new NGS panel, called compact panel, characterized by high sensitivity, with detection limits for mutations of 0.14%, 0.20%, 0.48%, 0.24%, and 0.20% for EGFR exon 19 deletion, L858R, T790M, BRAF V600E, and KRAS G12C, respectively. Mutation detection also had a high quantitative ability, with correlation coefficients ranging from 0.966 to 0.992. The threshold for fusion detection was 1%. The panel exhibited good concordance with the approved tests. The identity rates were as follows: EGFR positive, 100% (95% confidence interval, 95.5-100); EGFR negative, 90.9 (82.2-96.3); BRAF positive, 100 (59.0-100); BRAF negative, 100 (94.9-100); KRAS G12C positive, 100 (92.7-100); KRAS G12C negative, 100 (93.0-100); ALK positive, 96.7 (83.8-99.9); ALK negative, 98.4 (97.2-99.2); ROS1 positive, 100 (66.4-100); ROS1 negative, 99.0 (94.6-100); MET positive, 98.0 (89.0-99.9); MET negative 100 (92.8-100); RET positive, 93.8 (69.8-100); RET negative, 100 (94.9-100). The analytical performance showed that the panel could handle various types of biopsy samples obtained by routine clinical practice without requiring strict pathological monitoring, as in the case of conventional NGS panels.

RET fusion mutation detected by re-biopsy 7 years after initial cytotoxic chemotherapy: A case report

Personalized medicine using molecular-targeted drugs to achieve better therapeutic response and long-term prognosis is common practice for lung cancer treatment. However, in cases before gene batch tests were available, medical treatment continued without the detection of rare mutations. We report a sixty-seven-old year man diagnosed with adenocarcinoma T1cN3M1a, stage IVA. Initial screening performed 7 years earlier using EGFR mutation and ALK immunohistochemical tests were negative. Although first-line cytotoxic combination chemotherapy was remarkably effective, a gradual regression of the primary lesion was noted. After a recent bronchoscopic re-biopsy, RET fusion was detected by gene panel test. In addition, we were able to confirm RET from FFPE specimens obtained from 7-year-old pleural effusion cell blocks. Subsequent administration of the molecular-targeted drug selpercatinib, was highly effective for the primary lesion and all metastatic lesions including brain metastases. We describe a case of RET fusion-positive lung cancer where molecular targeted therapy and cytotoxic drug showed a drastic response and long-term therapy was well maintained. Next generation sequencing was able to correctly diagnose RET fusion mutation using re-biopsy specimen after going undiagnosed for 7 years.