Daily Respiratory Research Analysis
Three studies advance respiratory medicine across diagnostics and oncology. A prospective study shows bronchial washing fluid supernatant (BWFS) is a high-yield liquid biopsy for genotyping advanced NSCLC, rivaling tissue and outperforming plasma. A large test-performance study demonstrates that nasal CXCL10 can triage respiratory viral infections, while CSF ctDNA profiling in EGFR-mutant NSCLC leptomeningeal metastasis (LM) reveals richer mutation landscapes than plasma and identifies prognosti
Summary
Three studies advance respiratory medicine across diagnostics and oncology. A prospective study shows bronchial washing fluid supernatant (BWFS) is a high-yield liquid biopsy for genotyping advanced NSCLC, rivaling tissue and outperforming plasma. A large test-performance study demonstrates that nasal CXCL10 can triage respiratory viral infections, while CSF ctDNA profiling in EGFR-mutant NSCLC leptomeningeal metastasis (LM) reveals richer mutation landscapes than plasma and identifies prognostic treatment factors after third-generation EGFR-TKI resistance.
Research Themes
- Liquid biopsy innovation for respiratory oncology
- Host-response biomarkers for viral respiratory infection triage
- CSF genomics to guide management after EGFR-TKI resistance
Selected Articles
1. Bronchial washing fluid supernatant serves as a novel liquid biopsy specimen for genome profiling in advanced non-small cell lung cancer.
In a prospective cohort of advanced NSCLC, BWFS provided genotyping performance comparable to tumor tissue and superior to plasma, including higher mutation detection and sensitivity. TMB estimates from BWFS strongly correlated with tissue, and BWFS better captured CNVs and fusions than plasma.
Impact: This study introduces BWFS as a practical, high-yield liquid biopsy when tissue is limited, directly informing targeted therapy selection in advanced lung cancer.
Clinical Implications: BWFS can be integrated into bronchoscopy workflows to obtain actionable genomic data when tissue is scant, improving detection of CNVs/fusions and reliable TMB estimation to guide targeted and immunotherapy decisions.
Key Findings
- BWFS showed a higher mutation detection rate than plasma (96.4% vs 85.7%) and matched tissue performance.
- Using tissue as reference, BWFS sensitivity exceeded plasma (78.22% vs 36%).
- TMB estimates from BWFS and tissue were highly correlated (Pearson r = 0.97).
- BWFS outperformed plasma for detecting CNVs and gene fusions.
Methodological Strengths
- Prospective enrollment with matched triad sampling (BWFS, tissue, plasma).
- Targeted NGS panels covering 168–520 cancer-related genes with concordance analyses.
Limitations
- Single-center, small sample size with only 28 complete triads.
- Clinical outcome impact and turnaround time were not assessed.
Future Directions: Multicenter validation of BWFS workflows, standardization of collection/processing, and prospective trials assessing clinical decision impact and cost-effectiveness.
BACKGROUND: Tumor tissue is the primary substrate for molecular testing in advanced lung cancer. However, obtaining sufficient tissue samples from biopsy for molecular testing often be challenging for some patients. Bronchial washing fluid supernatant (BWFS), which contains tumor-derived DNA, may serve as a supplement for genotyping. The aim of this study is to assess the efficacy and precision of detecting gene alterations in BWFS samples and evaluate their clinical potential. PATIENTS AND METHODS: Thirty-eight stage III-IV non-small cell lung cancer (NSCLC) patients were prospectively enrolled between June 2022 and May 2024. The BWFS, matched tumor tissue (TIS), and plasma (PLA) from each patient were collected simultaneously, and all samples were subjected to targeted next-generation sequencing (NGS) of 520 cancer-related genes or 168 cancer-related genes. RESULTS: In the cohort of 38 patients, 28 had simultaneous NGS results from three distinct samples. compared with PLA, BWFS contains more abundant tumor-derived DNA and exhibited a higher maximum allelic frequency (max_AF) and elevated mutation detection rate (BWFS: 96.4 %, PLA: 85.7 %), in concordance with TIS (BWFS: 96.4 %, TIS: 100 %). A total of 536 mutation events were detected from the three sample types (TIS: 225, BWFS: 209, PLA: 102). Using TIS as the gold standard, BWFS demonstrated superior sensitivity compared to PLA (78.22 % vs. 36 %). For different variations, copy number variations (CNVs) and fusions were more challenging to detect in PLA compared to BWFS. The estimates of tumor mutational burden (TMB) based on TIS and BWFS were highly correlated (Pearson r = 0.97). CONCLUSION: Our study is the first to demonstrate that BWFS performs comparably to matched TIS and superiorly to PLA for genotyping advanced NSCLC via NGS. BWFS emerges as a valuable specimen, particularly in patients with insufficient tumor tissue.
2. Nasal biomarker testing to rule out viral respiratory infection and triage samples: a test performance study.
In 1088 nasopharyngeal samples, nasal CXCL10 achieved AUC 0.87 versus PCR, and modeling indicated substantial PCR reduction at low prevalence (NPV 0.975 at 5% prevalence). False negatives clustered among patients on specific chemotherapy and those with low viral loads.
Impact: A single host-response biomarker enabling pan-viral rule-out could streamline outbreak control and routine screening, mitigating resource constraints and assay fragmentation.
Clinical Implications: CXCL10 testing can triage likely negatives during low-prevalence periods, reducing PCR burden and turnaround time in EDs, long-term care, and pre-procedural settings, while PCR remains for confirmatory diagnosis.
Key Findings
- CXCL10 predicted respiratory virus positivity with AUC 0.87 (95% CI 0.85–0.90) against PCR.
- Modeling suggests at 5% prevalence, 92% of samples would screen negative with NPV 0.975, substantially reducing PCR testing.
- False negatives were associated with specific chemotherapeutic agents and low viral load.
Methodological Strengths
- Large, mixed-age sample size (n=1088) with direct comparison to multiplex PCR.
- Quantitative performance metrics (AUC) plus resource-use modeling and EMR-driven false-negative analysis.
Limitations
- Single biomarker approach may underperform in immunosuppressed hosts or very early infection.
- Study design appears cross-sectional; impact on clinical outcomes and prospective workflow integration not tested.
Future Directions: Prospective implementation trials across settings to define thresholds, cost-effectiveness, and integration with multiplex platforms; evaluation in immunocompromised populations.
BACKGROUND: The COVID-19 pandemic revealed an urgent need for practical screening tests to rule out respiratory virus infection, both for managing outbreaks and for routine screening in high-risk settings. PCR is the gold standard test for respiratory virus diagnosis but requires specialised equipment, uses different assays for each virus, and often excludes emerging viruses. The goal of this study was to evaluate a pan-viral host biomarker to rule out respiratory virus infection. We used CXCL10, a cytokine induced in the nasal mucosa in response to diverse respiratory viruses. METHODS: We compared immunoassay for CXCL10 to respiratory virus PCR panel results in 1088 nasopharyngeal samples from adults and children with an overall viral prevalence of 32.6% by PCR. Using this data, we mathematically modelled the impact of CXCL10 biomarker testing on patient triage and resource savings at different viral prevalences. We also explored clinical features associated with false negatives using automated data extraction from electronic medical records. FINDINGS: CXCL10 accurately predicted virus positivity (A.U.C. 0.87, 95% C.I. 0.85-0.90). Mathematical modelling predicted that CXCL10 screening would enable a significant reduction in PCR testing, especially when viral prevalence is low (e.g. 92% of samples testing negative when viral prevalence is 5%, NPV = 0.975). Outlier analysis identified specific chemotherapeutic drugs and low viral load as features associated with false negatives. INTERPRETATION: These results demonstrate the utility of a nasopharyngeal biomarker to rule out respiratory infection, with potential applications in outbreak management and/or routine screening in high-risk settings. FUNDING: Yale-New Haven Hospital Innovation Fund and NIH.
3. Genomic profiling and prognostic factors of leptomeningeal metastasis in EGFR-mutant NSCLC after resistant to third-generation EGFR-tyrosine kinase inhibitors.
In EGFR-mutant NSCLC with LM after third-generation EGFR-TKI resistance, CSF ctDNA outperformed plasma for mutation detection and pathway mapping, with higher ctDNA abundance and richer CNVs. Prognosis was associated with ECOG PS 1–2, furmonertinib plus bevacizumab, and higher-dose pemetrexed for intraventricular chemotherapy.
Impact: By establishing CSF ctDNA as a superior substrate for genomic profiling in LM and identifying treatment combinations linked to improved outcomes, this study directly informs management strategies in a high-mortality setting.
Clinical Implications: Routine CSF ctDNA profiling should be considered in LM to uncover actionable alterations missed in plasma and to guide therapy, including potential use of furmonertinib plus bevacizumab and optimized pemetrexed dosing for IVC in suitable patients.
Key Findings
- CSF had higher ctDNA abundance than plasma (0.76 vs 0.21; P < 0.001) and higher detection of EGFR, TP53 and copy-number alterations.
- Pathways enriched in CSF included cell cycle (80% vs 23%), KRAS/RAF (27% vs 8%), and WNT (18% vs 4%).
- Median intracranial PFS and OS after LM were 6.60 and 14.42 months; ECOG PS 1–2, furmonertinib plus bevacizumab, and higher-dose pemetrexed for IVC predicted better survival.
Methodological Strengths
- Relatively large LM cohort (n=116) with paired CSF and plasma NGS.
- Multivariate survival analysis to identify independent prognostic factors.
Limitations
- Single-center, retrospective design with potential selection and treatment confounding.
- Therapeutic associations are not randomized and require prospective validation.
Future Directions: Prospective trials incorporating CSF ctDNA-guided therapy selection in LM, and randomized evaluation of furmonertinib plus bevacizumab and intraventricular pemetrexed dosing strategies.
BACKGROUND: Leptomeningeal metastasis (LM) is a devastating complication of advanced non-small cell lung cancer (NSCLC). Currently, there is no valid data and effective treatment for LM after resistance to third-generation EGFR-TKIs. This study aimed to analyze the genomic profiling and prognostic factors of EGFR-mutant NSCLC-LM after resistance to third-generation EGFR-TKIs. METHODS: This study included 116 patients with EGFR-mutated NSCLC-LM at the Affiliated Brain Hospital of Nanjing Medical University from January 2021 to January 2024. Circulating tumor DNA from cerebrospinal fluid (CSF) and matched plasma samples were analyzed using next-generation sequencing (NGS). Genomic profiling, clinical features, and prognosis were collected and analyzed. RESULTS: ctDNA abundance in CSF was higher than in paired plasma samples (0.76 vs 0.21, P < 0.001). Compared to plasma, mutations were more easily detected in CSF, including EGFR mutations (73 % vs. 29 %, P < 0.001), TP53 mutations (61 % vs. 35 %, P＜0.001), CDK4_amp (57 % vs 0, P ＜ 0.001), CDKN2A_del (27 % vs. 0, P ＜ 0.001), EGFR_amp (22 % vs. 0, P ＜ 0.001), and CDK12 mutations (12 % vs. 2 %, P = 0.006). Pathway analysis indicates that genes enriched in CSF are altered in multiple oncogenic signaling pathways, including cell cycle (80 % vs 23 %, P < 0.001), KRAS/RAF (27 % vs 8 %, P < 0.001), and WNT (18 % vs 4 %, P = 0.002) pathways. Furthermore, CSF exhibits significantly greater copy number variations (CNVs; P = 0.022) and missense mutations (P = 0.015) compared to plasma. The median intracranial progression-free survival and overall survival after LM diagnosis were 6.60 and 14.42 months, respectively. Multivariate analysis demonstrated that baseline Eastern Cooperative Oncology Group performance status (ECOG PS) 1-2, ≥40 mg pemetrexed per time for IVC, and the combination of furmonertinib and bevacizumab were independent favorable predictors of survival. Finally, we reported a case of LM in which ctDNA dynamic changes in CSF were well consistent with his clinical condition. CONCLUSIONS: Compared to plasma, CSF ctDNA is more sensitive and specific in detecting somatic mutations and metastasis-related pathways. Good performance status, furmonertinib combined with bevacizumab, and high-dose pemetrexed for IVC can improve the prognosis of NSCLC-LM patients after resistance to third-generation EGFR-TKIs.