Clinical application of the AMOY 9-in-1 panel to lung cancer patients

Impact of EGFR Mutation Subtypes on Response to Chemoimmunotherapy and Chemotherapy in Non-Small-Cell Lung Cancer After EGFR-TKI Failure

BACKGROUND

The efficacy of immune checkpoint inhibitor (ICI) monotherapy on non-small-cell lung cancer (NSCLC) varies by epidermal growth factor receptor (EGFR) mutation subtypes. However, the impact of these subtypes on the clinical outcomes of chemoimmunotherapy (Chemo+ICI) or platinum-based chemotherapy (Chemo) in real-world practice remains unclear.

OBJECTIVE

This study evaluated the impact of EGFR mutation subtypes on NSCLC treatment outcomes of Chemo and Chemo+ICI.

PATIENTS AND METHODS

We retrospectively analyzed patients with advanced or recurrent EGFR-mutant NSCLC from 20 institutions between January 2017 and July 2022. Patients received Chemo with or without ICI after failure of EGFR-tyrosine kinase inhibitors. Common EGFR mutations were categorized as exon 19 deletions and exon 21 L858R mutations.

RESULTS

Among the 403 patients, 205 (50.9%) had exon 19 deletions, and 198 (49.1%) had L858R mutations. For patients with L858R mutations, Chemo+ICI significantly improved progression-free survival (PFS) compared with Chemo (7.0 vs 5.3 months; p = 0.04). However, no significant difference in PFS was observed between treatments for patients with exon 19 deletions (6.7 vs 6.0 months; p = 0.96). Multivariate analysis identified Chemo+ICI as an independent predictor of PFS in patients with L858R mutations (hazard ratio 0.63; 95% confidence interval 0.43-0.92; p = 0.02).

CONCLUSIONS

Among patients with common EGFR mutation subtypes, those with L858R mutations demonstrated significantly improved PFS with Chemo+ICI than with Chemo. These findings suggest that Chemo+ICI may offer a more effective treatment option for patients with L858R-mutant NSCLC, warranting further investigation in prospective studies.

Efficacy of EGFR tyrosine kinase inhibitors in patients with non-small cell lung cancer with EGFR exon 19 insertions: clinical-genomic, preclinical analysis through LC-SCRUM-Asia (multi-institutional genomic screening registry)

BACKGROUND

EGFR exon 19 insertions (EGFRex19ins) are rare EGFR mutations. Their clinical-genomic characteristics and outcomes with EGFR-tyrosine kinase inhibitors (TKIs) remain uncertain.

METHODS

We evaluated the clinical-genomic characteristics and outcomes of EGFR-TKIs for EGFRex19ins in the multi-institutional prospective lung cancer genomic screening project (LC-SCRUM-Asia). We also studied preclinical Ba/F3 models expressing EGFR-K745_E746insIPVAIK (Ba/F3-IPVAIK) to investigate their sensitivity to 1st-, 2nd-, 3rd-generation, and EGFR exon 20 insertion-active TKIs.

RESULTS

In LC-SCRUM-Asia, 16,204 NSCLC patients were enrolled from March 2015 to December 2023. EGFRex19ins were detected in 13 samples (0.1 % of NSCLC). The median age was 72 years (range, 38-80); most patients were female (77 %), had adenocarcinoma (92 %), and were never-smokers (62 %). Twelve patients (93 %) had EGFR-K745_E746insIPVAIK, while one (7 %) had EGFR-K745_E746insVPVAIK. The most frequent co-mutation was TP53 (62 %); no patients had other driver alterations. Six patients (46 %) tested positive for EGFR exon 19 deletions with PCR-based Cobas EGFR test, likely due to cross-reactivity arising from sequence homology. Twelve patients received EGFR-TKIs; five (42 %) experienced partial response. In the preclinical study, Ba/F3-IPVAIK showed the highest sensitivity to 2nd-generation EGFR-TKIs compared to other EGFR-TKIs. Structural studies supported these consistent results. When broken down by EGFR-TKI generations, response rates for 1st-, 2nd-, and 3rd-generation TKIs were 50 % (1/2), 80 % (4/5), and 0 % (0/5), respectively. The median PFS for 1st-, 2nd-, and 3rd-generation TKIs were 8.7 (95 % CI, 7.4-NR), 14.7 (95 % CI, 8.0-NR), and 4.4 (95 % CI, 3.4-NR) months, respectively.

CONCLUSION

Our preclinical, structural, and clinical findings indicate 2nd-generation EGFR-TKIs are more effective for EGFRex19ins compared to other TKIs.

Drug Resistance in Late-Stage Epidermal Growth Factor Receptor (EGFR)-Mutant Non-Small Cell Lung Cancer Patients After First-Line Treatment with Tyrosine Kinase Inhibitors

The development of tyrosine kinase inhibitors (TKIs) for late-stage epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) represented a drastic change in the treatment of late-stage lung cancer. Drug resistance develops after a certain period of first-line TKI treatment, which has led to decades of changing treatment guidelines for EGFR-mutant NSCLC. This study discussed the potential mechanisms of drug resistance against first-line TKI treatment and potential successive treatment strategies. Next-generation sequencing (NGS) may play a role in the evaluation of drug resistance in first-line TKI treatment. Emerging combination regimens and ongoing trials were discussed. Potential future strategies for treatment and for the management of drug resistance were proposed in this study.

Examining the Formalin Fixation Method for Maintaining High RNA Quality in Surgical Lung Specimens

BACKGROUND

Multiplex genetic testing is recommended when treating nonsmall cell lung cancer. A certain percentage of test failures in RNA assays owing to poor surgical specimen quality have been documented, and fixation failure is a possible cause. At our institution, sheet-like fixation is performed to reduce fixation time. This study aimed to compare the quality of RNA from resected lung cancer specimens following different fixation methods.

METHODS

Sheet-like fixation specimens (n = 15), conventional fixation specimens of the same resected lungs (n = 15), and other lung cancer specimens collected for conventional fixation and subjected to multiplex gene-panel testing (n = 22) were retrospectively examined. RNA was extracted from each specimen. RNA quality and quantity were compared, and the success rate of multiplex gene-panel testing was determined.

RESULTS

The DV200 value was significantly higher in RNA extracted from sheet-like fixation samples (median 47.5%, interquartile range [IQR]:40.3-51.5) compared with RNA extracted from conventionally fixed samples or conventionally fixed samples of other patient specimens (median 21%, IQR:5.3-29.8 and median 16.3%, IQR:9.5-27.1, respectively). No significant difference was observed in nucleic acid concentration. The multiplex genetic analysis success rate was 95% with conventional methods (one failure); however, it was 100% with the sheet-like fixation method.

CONCLUSION

Sheet-like fixation preserved RNA extracted from lung cancer specimens, resulting in lesser degradation than with conventional fixation.

Remarkable Response to Dabrafenib and Trametinib in a V-Raf Murine Sarcoma Viral Oncogene Homolog B (BRAF) V600E-Mutated Lung Adenocarcinoma Patient With Poor Performance Status and Respiratory Failure: A Case Report

We report the case of a 73-year-old man with progressive dyspnea and acute respiratory failure. Imaging revealed extensive infiltrative shadows in the right lung. A bronchoscopic biopsy confirmed primary lung adenocarcinoma harboring the BRAF V600E mutation. The patient's performance score was three, requiring four liter/minute of supplemental oxygen to maintain an oxygen saturation of 90%. After a thorough discussion and informed consent, treatment with dabrafenib and trametinib was initiated despite the risks associated with his condition. Following the initiation of therapy, the patient exhibited significant clinical and radiological improvements. He continues to receive the combination therapy without significant adverse events, and his disease remains stable. We report this as the first case that demonstrates dabrafenib and trametinib can be effective and well-tolerated in patients with BRAF V600E mutated non-small cell lung cancer (NSCLC), even in those with poor performance status and acute respiratory failure. This result provides early evidence supporting the cautious use of molecular-targeted therapies in such patients.

Patient-Initiated Nationwide Survey on Testing for Actionable Oncogenic Drivers in Non-Small Cell Lung Cancer in Japan

BACKGROUND

Previous reports indicated still low implementation rates of multigene testing for advanced non-small cell lung cancer (NSCLC) in Japan.

METHODS

This is a retrospective study launched at the initiative of lung cancer patients. Patients with stage IV NSCLC from January 2019 to December 2022 were investigated for testing of 8 actionable oncogenic drivers with targeted therapies available as of 2022.

RESULTS

A total of 15,719 patients were included. Between 2019 and 2022, the percentage of patients who were not tested for any actionable oncogenic drivers remained the same, ranging from 21.5% to 33.1%. However, since late 2021, the percentage of patients tested for five or more actionable oncogenic drivers has increased. Across hospital categories and regions, the number of actionable oncogenic drivers tested was similar.

CONCLUSIONS

This patient-initiated national survey in Japan reveals the recent nationwide increase in testing rates for actionable oncogenic drivers in Advanced NSCLC.

A Prospective Observational Study on Analyzing Lung Cancer Gene Mutation Variant Allele Frequency (VAF) and Its Correlation with Treatment Efficacy

A few studies have reported on the variability of the variant allele frequency (VAF) of gene mutations and the relationship between VAF and the therapeutic effect of molecular-targeted drugs. This joint study was conducted from May 2020 to January 2022 between St. Marianna University School of Medicine and the DNA Chip Research Institute. Cytology samples were used to verify the usefulness of a lung cancer compact panel test, which is a high-sensitivity next-generation sequencing (NGS) gene panel test. We analyzed the distribution of VAF and the duration of the initial molecular-targeted drug administration in patients with advanced-stage epidermal growth factor receptor (EGFR) mutations. Of the 196 patients diagnosed with non-small cell carcinoma (NSCLC), gene mutations were detected in 114 (58.2%) cases and in 68.7% of patients with adenocarcinomas (an increased detection rate). A VAF of 30% or more for DNA mutations was confirmed in 35 patients (33.7%), 10% to <30% in 38 (36.5%), and <10% in 31 (29.8%), including 18 patients (17.3%) with <6%, which is considered the lower limit of the LOD for other companion diagnostic kits. EGFR mutations were detected in 59 patients (30%), of whom 35 were in an advanced stage and received molecular-targeted drugs as their initial treatment. Groups A and B comprised patients with a VAF of ≥10% and <10%, respectively, with 27 patients (median VAF 30.6%, range 11.4-77%) in group A and 8 (median VAF 5.4%, range 0.1-8.5%) in group B. The duration of the administration of molecular-targeted drugs was 17 months (range 3-42 months) in group A and 14 months (range 1-45 months) in group B, with no statistically significant difference between the two groups (p-value = 0.7). Twenty-seven percent of patients had a VAF < 10%. Even in patients with a low VAF for gene mutations, sufficient therapeutic effects were observed with molecular-targeted drugs, suggesting the importance of detecting mutations using a highly sensitive method at initial diagnosis. Further prospective validation studies of a larger number of cases are warranted.

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.

Preservation of cfRNA in cytological supernatants for cfDNA & cfRNA double detection in non-small cell lung cancer patients

BACKGROUD

Supernatants from various cytological samples, including body cavity effusion, sputum, bronchoalveolar lavage fluid (BALF), and needle aspiration, have been validated for detecting genetic alterations using cell-free DNA (cfDNA) in patients with non-small cell lung cancer (NSCLC). However, the sensitivity of fusion variations detection remains challenging. The protection of cell-free RNA (cfRNA) is critical for resolving the issue.

METHODS

A protective solution (PS) was applied for preserving cfRNA in cytological supernatant (CS), and the quality of protected cfRNA was assessed by cycle threshold (CT) values from reverse transcription quantitative polymerase chain reaction (RT-qPCR). Furthermore, we collected an additional set of malignant cytological and matched tumor samples from 84 NSCLC patients, cfDNA & cfRNA extraction and double detection for driver gene mutations was validated using the multi-gene mutations detection by RT-qPCR.

RESULTS

Under the optimal protection system, 91.0% (101/111) of cfRNA were protected effectively. Among the 84 NSCLC patient samples, seven cytological samples failed the tests. In comparison with tumor samples, the overall sensitivity and specificity of detecting driver genes of supernatant cfDNA and cfRNA were 93.8% (74/77) and 100% (77/77), respectively. Notably, when focusing exclusively on patients with fusion gene changes, both sensitivity and specificity reached 100% (11/11) for EML4-ALK, ROS1, RET fusions, and MET ex14 skipping.

CONCLUSION

These findings suggest that cfDNA & cfRNA extraction and double detection strategy recommended in this study improve the accuracy of driver genes mutations test, especially for RNA-based assay.

Risk Stratification According to Baseline and Early Change in Neutrophil-to-Lymphocyte Ratio in Advanced Non-Small Cell Lung Cancer Treated with Chemoimmunotherapy: A Multicenter Real-World Study

BACKGROUND

Chemoimmunotherapy is a standard treatment for advanced non-small-cell lung cancer (NSCLC). However, data on clinical predictive factors remain scarce.

OBJECTIVE

We aim to identify clinical biomarkers in patients undergoing chemoimmunotherapy.

METHODS

This multicenter, real-world cohort study included chemonaive patients who underwent chemoimmunotherapy between December 2018 and May 2022. Multivariate analysis was used to determine associations between survival outcomes and patient background, including baseline neutrophil-to-lymphocyte ratio (NLR) and its dynamic change (ΔNLR). To further investigate the clinical significance of NLR, patients were classified based on their peripheral immune status, defined by a combination of NLR and ΔNLR.

RESULTS

The study included 280 patients with 30.1 months of median follow-up. Multivariate analysis revealed that older individuals, poor performance status, tumor proportion score < 1%, liver metastasis, baseline NLR ≥ 5, and ΔNLR ≥ 0 independently correlated significantly with shorter progression-free and overall survival (OS). Patients with high peripheral immune status (defined as NLR <5 and ΔNLR < 0) significantly improved long-term survival (2-year OS rate of 58.3%), whereas those with low peripheral immune status (defined as NLR ≥ 5 and ΔNLR ≥ 0) had extremely poor outcomes (2-year OS rate of 5.6%). Safety profiles did not differ significantly in terms of severe adverse events and treatment-related death rates despite the patients' peripheral immune status (P = 0.46 and 0.63, respectively).

CONCLUSIONS

Our study provides real-world evidence regarding clinical prognostic factors for the efficacy of chemoimmunotherapy. The combined assessment of baseline NLR and ΔNLR could facilitate the identification of patients who are likely to achieve a durable response from chemoimmunotherapy.

The Tumor Fraction Estimated by Rapid On-Site Evaluation Is Useful for Assessing the Suitability of Biopsy Specimens for Multiplex Genetic Testing

INTRODUCTION

Multiplex genetic testing (MGT) has become the mainstream method for genetic mutation testing in the field of lung cancer treatment, but the suitability criteria for MGT biopsy specimens are stringent. Although rapid on-site evaluation (ROSE) is considered a useful method for obtaining the suitable biopsy specimens for MGT, no direct comparisons of ROSE and MGT are available. In this study, we first evaluated the accuracy of MGT and ROSE in our hospital. Then, we explored the potential utility of the cytological findings of ROSE for indicating the adequacy of biopsy specimens for MGT.

METHODS

These analyses were performed retrospectively using the data of 74 patients with lung cancer who underwent ROSE at our hospital in 2020-2022.

RESULTS

Regarding the accuracy of MGT, the success rate was 97.9% and the frequency of epidermal growth factor receptor mutation in adenocarcinoma cases was 34.6%. The results of ROSE were then compared with histological diagnoses. The sensitivity and positive predictive value were 95.9% and 100.0%, respectively. To analyze the utility of the ROSE results for determining the adequacy of biopsy specimens for MGT, we determined the tumor fraction in the ROSE preparations (ROSE-T%) and the tumor fraction (B-T%)/tumor cell number (B-TN) in the biopsy specimens. When the threshold of the ROSE-T% was set at 80%, there were statistically significant biases of the B-T% ≥20%/B-TN ≥300 cases between the ROSE-T% ≥80% and <80% groups.

CONCLUSION

This is the first report to suggest the utility of ROSE-T% in assessing the suitability of biopsy specimens for MGT. This predictive ability may add further value to ROSE and help reduce the time required for diagnostic testing, and thereby the patient burden.

Suitability of frozen cell pellets from cytology specimens for the Amoy 9-in-1 assay in patients with non-small cell lung cancer

BACKGROUND

The AmoyDx Pan lung cancer PCR panel (AmoyDx PLC panel) has been approved as a companion diagnostic tool for multiple anticancer agents in patients with non-small cell lung cancer (NSCLC). However, the suitability of cytology specimens as samples for the AmoyDx PLC panel remains unclear. We evaluated the performance of frozen cell pellets from cytology specimens (FCPs) in the Amoy 9-in-1 assay, a preapproval assay of the AmoyDx PLC panel.

METHODS

We retrospectively collected data of NSCLC patients enrolled in LC-SCRUM-Asia from the Shizuoka Cancer Center between September 2019 and May 2021.

RESULTS

A total of 49 cases submitted FCPs for evaluation of oncogenic driver alterations and were assessed using Amoy 9-in-1 and next-generation sequencing (NGS) assays. The success rates of DNA and RNA analyses using the Amoy 9-in-1 were both 100%, compared with 86% and 45%, respectively, using NGS assays. Oncogenic driver alterations were detected in 27 (55%) and 23 (47%) patients using Amoy 9-in-1 and NGS, respectively. No inconsistent results were observed among 19 cases in which both assays showed successful detection. In the remaining 30 cases, 10 had inconsistent results: nine oncogenic driver alterations (3 MET, 2 ALK, 2 ROS1, and 2 KRAS) were detectable only in Amoy 9-in-1, and one epidermal growth factor receptor (EGFR) mutation was detectable only in NGS.

CONCLUSION

FCPs can be successfully used in the AmoyDx PLC panel, with higher success rate compared with the NGS assay. The AmoyDx PLC panel may be an option in cases when insufficient tissue sample is available for the NGS assay.

Brief Report: Tepotinib as a Treatment Option in MET Exon 14 Skipping-Positive Lung Cancers-Investigating Discordance Between ArcherMET and the Oncomine Dx Target Test

Introduction

NSCLC is a leading cause of cancer-related mortality worldwide. Specific genetic alterations, such as MET exon 14 (METex14) skipping, have been identified in NSCLC, allowing targeted therapy. Tepotinib, a highly selective MET inhibitor, has displayed promise in patients with advanced NSCLC. Nevertheless, challenges arise when identifying treatment strategies for patients with discordant results regarding METex14 skipping detection between diagnostic tests.

Methods

We investigated patients with NSCLC and discordant results for METex14 skipping between the Oncomine Dx Target Test (ODxTT) and ArcherMET. Clinical response, adverse events, and the duration of tepotinib treatment were assessed, and statistical analysis was performed.

Results

Among the 19 patients deemed METex14 skipping positive by ODxTT, only 10 had concordant results with ArcherMET. The number of METex14 skipping reads detected by ODxTT was significantly lower in discordant cases. Of the 19 patients, 14 received tepotinib, and comparable response and disease control rates were observed in both concordant and discordant cases. The duration of treatment did not significantly differ between the two groups.

Conclusions

Our findings suggest that tepotinib has comparable therapeutic effects in patients with METex14 skipping-positive NSCLC irrespective of the concordance of results between ODxTT and ArcherMET. Tepotinib is a possible treatment option for patients with METex14 skipping, even in patients with discordant test results.

Comparison of diagnostic performance between Oncomine Dx target test and AmoyDx panel for detecting actionable mutations in lung cancer

Companion diagnostic (CDx) tests play important roles in identifying oncogenic driver genes and tailoring effective molecularly targeted therapies for lung cancer patients. In Japan, the Oncomine Dx target test (ODxTT) and the AmoyDx pan lung cancer PCR panel (AmoyDx) are prominent CDx tests and only one of these tests is covered by the domestic insurance system. However, these CDx tests cover different target regions and apply different technologies (ODxTT is amplicon-based next-generation sequencing and AmoyDx is multiplex PCR-based assay), which may lead to missing of actionable mutations affecting patient prognosis. Here, we performed a direct comparison analysis of 1059 genetic alterations of eight driver genes from 131 samples and evaluated the concordance between two CDx tests for detecting actionable variants and fusions. When excluding the eight uncovered variants (ODxTT: two variants, AmoyDx: six variants), the overall percent agreement was 97.6% (1026/1051) with 89.0% of overall positive percent agreement (89/100) and 98.5% of overall negative percent agreement (937/951). Of the 25 discordant genetic alterations, two were undetected despite being covered in the AmoyDx (one EGFR variant and one ROS1 fusion). Furthermore, there were potential false positives in the ODxTT (nine MET exon 14 skippings) and in the AmoyDx (five variants, six ROS1 and three RET fusions). These potential false positives in the AmoyDx likely due to non-specific amplification, which was validated by the unique molecular barcoding sequencing. The ODxTT missed two uncovered EGFR rare variants, which was visually confirmed in the raw sequencing data. Our study provides insights into real-world performance of CDx tests for lung cancer and ensures reliability to advance precision medicine.

Retrospective Analysis to Optimize the Detection of MET Exon 14 Skipping Mutations in Non-Small Cell Lung Cancer

Our study optimized METex14 skipping mutation detection by analyzing 223 Oncomine™ Focus Assay-positive cases using Pan Lung Cancer PCR Panel and reverse transcription (RT)-PCR. Among the 11 METex14 skipping mutation-positive cases (average read counts: 1390), 2 with Oncomine™ Focus Assay read counts of 2540 and 10,177 were positive on all platforms. Those with Oncomine™ Focus Assay read counts ranging from 179 to 612 tested negative elsewhere. Specimens with low ratios (average ratio: 0.12% for nine cases) may yield false-positive results. Our results suggested that monitoring read counts and ratios and validating the results with RT-PCR are crucial to prevent false positives.

Airway stenosis secondary to mediastinal lymph node metastasis of lung adenocarcinoma treated with AERO stent and osimertinib: A case report

A woman in her mid-50s was admitted to our hospital with airway stenosis secondary to mediastinal lymph node enlargement. An AERO stent was placed under rigid bronchoscopy. Immediately after stent placement, tissue sampling was performed on the lymph nodes. Metastatic lesions were found to have an EGFR mutation (exon 19 deletion). Consequently, osimertinib treatment was initiated 15 days after stent placement. The tumour partially responded to osimertinib, and the airway stenosis improved. The patient underwent stent removal 66 days after stent placement. Our findings indicate that temporary oncological emergencies due to airway stenosis may be bridged by airway stenting.

Lung adenocarcinoma with EGFR L858R-K860I and L858R-L861F doublet mutations from which the L858R mutation is undetectable through the cobas EGFR mutation test v2

In East Asia, epidermal growth receptor factor (EGFR) mutations are the most prevalent and important biomarkers for treating patients with advanced lung cancer. However, as L858R doublet mutations are rare, commercially available EGFR tests may yield false-negative results. To determine whether the L858R mutation of the L858R-K860I and L858R-L861F doublet mutations could be identified using different types of EGFR detection tests and to describe the clinical response of patients with lung cancer with L858R doublet mutations to EGFR tyrosine kinase inhibitors (TKI). Information and samples from four patients with L858R doublet mutations, including three with L858R-K860I and one with L858R-L861F, were retrospectively collected from the archives of our department. For each case, the clinical response to EGFR-TKI was retrieved from the medical records. Archived formalin-fixed paraffin-embedded blocks were subjected to Sanger sequencing, the cobas and Idylla EGFR tests, the IntelliPlex-LCP-DNA assay, and AmoyDx PLC panel. L858R mutations were all detected by Sanger sequencing and the Idylla EGFR test but missed by the cobas assay. The AmoyDx PLC detected L858R only in cases with L858R-K860I while the IntelliPlex-LCP-DNA assay detected L858R in the case with L858R-L861F. Additionally, three of the patients, who had measurable tumors, showed partial responses to afatinib and osimertinib. The L858R mutation associated with L858R-K860I and L858R-L861F doublet mutations could be detected using Idylla but not cobas EGFR tests. Using next-generation sequencing analysis should be considered after initial negative reports from the cobas test, because patients with L858R doublet mutations may benefit from EGFR-TKIs.

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.

Comparison between next-generation sequencing and multiplex polymerase chain reaction assays for nonsmall-cell lung cancer molecular diagnosis

PURPOSE

Genetic mutation detection has become an important step in nonsmall-cell lung cancer (NSCLC) treatment because of the increasing number of drugs that target genomic rearrangements. A multiplex test that can detect multiple gene mutations prior to treatment is thus necessary. Currently, either next-generation sequencing (NGS)-based or polymerase chain reaction (PCR)-based tests are used. We evaluated the performance of the Oncomine Dx Target Test (ODxTT), an NGS-based multiplex biomarker panel test, and the AmoyDx Pan Lung Cancer PCR Panel (AmoyDx PLC panel), a real-time PCR-based multiplex biomarker panel test.

MATERIALS AND METHODS

Patients with histologically diagnosed NSCLC and a sufficient sample volume to simultaneously perform the AmoyDx PLC panel and ODxTT-M were included in the study. The success and detection rates of both tests were evaluated.

RESULTS

Biopsies revealed 116 cases of malignancies, 100 of which were NSCLC. Of these, 59 met the inclusion criteria and were eligible for analysis. The success rates were 100% and 98% for AmoyDx PLC panel and ODxTT-M, respectively. Nine driver mutations were detected in 35.9% and 37.3% of AmoyDx PLC and ODxTT-M panels, respectively. EGFR mutations were detected in 14% and 12% of samples using the AmoyDx PLC panel and ODxTT-M, respectively. Of the 58 cases in which both NGS and AmoyDx PLC panels were successful, discordant results were observed in seven cases. These differences were mainly due to different sensitivities of the detection methods used and the gene variants targeted in each test.

DISCUSSION

The AmoyDx PLC panel, a PCR-based multiplex diagnostic test, exhibits a high success rate. The frequency of the nine genes targeted for treatment detected by the AmoyDx PLC panel was comparable to the frequency of mutations detected by ODxTT-M. Clinicians should understand and use the AmoyDx PLC panel and ODxTT-M with respect to their respective performances and limitations.

Clinical application of the Lung Cancer Compact PanelTM using various types of cytological specimens in patients with lung cancer

BACKGROUND

The Lung Cancer Compact PanelTM (compact panel) is a gene panel that can detect driver alterations with high sensitivity in liquid samples, including tumor cells. This study examined the ability of a compact panel to detect genetic mutations in liquid specimens used in clinical practice.

METHODS

Three cohorts, bronchoscopic biopsy forceps washing (washing cohort), pleural effusion (pleural cohort), and spinal fluid (spinal cohort), were analyzed using the compact panel. Liquid samples were added into the GM (Genemetrics) tubes and analyzed. The washing cohort assessed the concordance rate of gene panel analysis outcomes in tissue specimens derived from the primary tumor. Meanwhile, the pleural cohort investigated the impact of storing specimens for 8 weeks and more on nucleic acid and mutation detection rates.

RESULTS

In the washing cohort (n = 79), the concordance rate with mutations detected in tissues was 75/79 (94.9 %). This rate reached 100 % when focusing solely on driver alterations for treatment. The pleural cohort (n = 8) showed no deterioration in nucleic acid quality or quantity after 8 weeks of storage in GM tubes. Similarly, in the spinal cohort (n = 9), spinal fluid with malignant cells exhibited driver alterations similar to those in the primary tumor. These findings underscore the efficacy of the compact panel in accurately identifying genetic mutations in different liquid specimens.

CONCLUSIONS

The compact panel is a reliable tool for detecting driver alterations in various cytological specimens. Its consistent performance across diverse sample types emphasizes its potential for guiding targeted therapies for patients with lung cancer and enhancing precision medicine approaches.

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.

Kristen rat sarcoma virus (KRAS) G12F-positive non-small cell lung cancer mimicking KRAS G12C positivity: A case report

Searching for driver gene alteration is a prerequisite for chemotherapy of non-small cell lung cancer. Due to its high sensitivity and concordance rate, the Amoy Dx Pan Lung Cancer PCR panel has been approved and is widely used in Japan. In this report, we describe a case in which a positive result for Kristen rat sarcoma virus (KRAS) exon2 p.G12F, a rare KRAS mutation, may have led to a false-positive result for KRAS exon2 p.G12C on AMOY. Genetic analysis in this case was performed by LC-SCRUM-Asia.

Utility of needle biopsy in centrally located lung cancer for genome analysis: a retrospective cohort study

BACKGROUND

It is essential to collect a sufficient amount of tumor tissue for successful next-generation sequencing (NGS) analysis. In this study, we investigated the clinical risk factors for avoiding re-biopsy for NGS analysis (re-genome biopsy) in cases where a sufficient amount of tumor tissue could not be collected by bronchoscopy.

METHODS

We investigated the association between clinical factors and the risk of re-genome biopsy in patients who underwent transbronchial biopsy (TBB) or endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and required re-genome biopsy in cases enrolled in LC-SCRUM Asia, a prospective nationwide genome screening project in Japan. We also examined whether the frequency of re-genome biopsy decreased between the first and second halves of the enrolment period.

RESULTS

Of the 572 eligible patients, 236 underwent TBB, and 134 underwent EBUS-TBNA. Twenty-four TBBs required re-genome biopsy, and multivariate analysis showed that the risk of re-genome biopsy was significantly increased in lesions where the tumor lesion was centrally located. In these cases, EBUS-TBNA should be utilized even if the lesion is a pulmonary lesion. However, it should be noted that even with EBUS-TBNA, lung field lesions are at a higher risk of re-canalization than mediastinal lymph node lesions. It was also found that even when tumor cells were detected in rapid on-site evaluation, a sufficient amount of tumor tissue was not always collected.

CONCLUSIONS

For centrally located pulmonary mass lesions, EBUS-TBNA, rather than TBB, can be used to obtain tumor tissues that can be analyzed by NGS.