CtDNA based molecular residual disease outcompetes carcinoembryonic antigen in predicting postoperative recurrence of non-small cell lung cancer.

Background: Carcinoembryonic antigen (CEA) has been routinely used as a postoperative monitoring biomarker for non-small cell lung cancer (NSCLC). Emergingly, circulating tumor DNA (ctDNA)-molecular residual disease (MRD) detection is a well-established prognostic marker, with better positive predictive value (PPV) and negative predictive value (NPV). However, the actual clinical efficiency of CEA in MRD context remain unknown. Hence, we conducted this study for direct comparison of CEA and MRD. Methods: Two cohorts were analyzed in this study. To investigate the prognostic and predictive value of CEA, we retrospective enrolled NSCLC patient stage IA2-IIIA (8th tumor-node-metastasis staging system) with longitudinal CEA between 2018 and 2019. We also performed a paired comparison of CEA and MRD in our previous published cohort. Survival data were analyzed using the Kaplan-Meier method, and comparisons were performed using the log-rank test. Sensitivity, specificity, PPV and NPV were calculated using the R package "epiR". McNemar's test was used to analyze the paired data. Statistical differences were set at a P value <0.05. Results: In the retrospective cohort, the sensitivity of longitudinal CEA was only 0.49 [95% confidence interval (CI): 0.37-0.60]. Even for patients with progressively elevated CEA levels, 32% of them still remained disease-free, with PPV of 0.68 (0.49-0.83) and NPV of 0.81 (0.77-0.85). Furthermore, we then compared CEA and MRD values in a previously described MRD cohort. As expected, CEA levels could not stratify the risk of recurrence in detectable versus undetectable MRD populations. Conclusions: MRD is superior to CEA in postoperative monitoring. there is insufficient evidence to support its use as postoperative monitoring tumor marker.

Adjuvant Therapy-Free Strategy for Stage IB to IIIA Non-Small-Cell Lung Cancer Patients After Radical Resection Based on Longitudinal Undetectable Molecular Residual Disease: Prospective, Multicenter, Single-Arm Study (CTONG 2201).

BACKGROUND: The utility of circulating tumor DNA to monitor molecular residual disease (MRD) has been clinically confirmed to predict disease recurrence in non-small cell lung cancer (NSCLC) patients after radical resection. Patients with longitudinal undetectable MRD show a favorable prognosis and might not benefit from adjuvant therapy. PATIENTS AND METHODS: The CTONG 2201 trial is a prospective, multicenter, single-arm study (ClinicalTrials.gov identifier, NCT05457049), designed to evaluate the hypothesis that no adjuvant therapy is needed for patients with longitudinal undetectable MRD. Pathologically confirmed stage IB-IIIA NSCLC patients who have undergone radical resection will be screened. Only patients with 2 consecutive rounds of undetectable MRD will be enrolled (first at days 3-10, second at days 30 ± 7 after surgery), and admitted for imaging and MRD monitoring every 3 months without adjuvant therapy. The primary endpoint is the 2-year disease-free survival rate for those with longitudinal undetectable MRD. The recruitment phase began in August 2022 and 180 patients will be enrolled. CONCLUSIONS: This prospective trial will contribute data to confirm the negative predictive value of MRD on adjuvant therapy for NSCLC patients. CLINICAL TRIAL REGISTRATION: NCT05457049 (CTONG 2201).

Lack of incremental value of three-dimensional measurement in assessing invasiveness for lung cancer.

OBJECTIVES: The aim of this study was to evaluate the performance of consolidation-to-tumour ratio (CTR) and the radiomic models in two- and three-dimensional modalities for assessing radiological invasiveness in early-stage lung adenocarcinoma. METHODS: A retrospective analysis was conducted on patients with early-stage lung adenocarcinoma from Guangdong Provincial People's Hospital and Shenzhen People's Hospital. Manual delineation of pulmonary nodules along the boundary was performed on cross-sectional images to extract radiomic features. Clinicopathological characteristics and radiomic signatures were identified in both cohorts. CTR and radiomic score for every patient were calculated. The performance of CTR and radiomic models were tested and validated in the respective cohorts. RESULTS: A total of 818 patients from Guangdong Provincial People's Hospital were included in the primary cohort, while 474 patients from Shenzhen People's Hospital constituted an independent validation cohort. Both CTR and radiomic score were identified as independent factors for predicting pathological invasiveness. CTR in two- and three-dimensional modalities exhibited comparable results with areas under the receiver operating characteristic curves and were demonstrated in the validation cohort (area under the curve: 0.807 vs 0.826, P = 0.059) Furthermore, both CTR in two- and three-dimensional modalities was able to stratify patients with significant relapse-free survival (P < 0.000 vs P < 0.000) and overall survival (P = 0.003 vs P = 0.001). The radiomic models in two- and three-dimensional modalities demonstrated favourable discrimination and calibration in independent cohorts (P = 0.189). CONCLUSIONS: Three-dimensional measurement provides no additional clinical benefit compared to two-dimensional.

Dynamic circulating tumor DNA during chemoradiotherapy predicts clinical outcomes for locally advanced non-small cell lung cancer patients.

The value of circulating tumor DNA (ctDNA) during chemoradiotherapy (CRT) remains unclear but is critical for detecting molecular residual disease (MRD). In this prospective study, we sequenced 761 blood samples from 139 patients with locally advanced non-small cell lung cancer treated with definitive radiation therapy (RT). ctDNA concentrations showed a significantly declining trend as CRT progressed at on-RT and after-RT time points versus baseline. Thirty-eight (27.3%) patients with early undetectable ctDNA at both on-RT (RT reached 40 Gy) and after-RT time points, indicating early response to CRT, had better survival outcomes for both with or without consolidation immune checkpoint inhibitors. Longitudinal undetectable MRD was found in 20.1% patients. The 2-year cancer-specific progression-free survival of these patients was 88.4%, corresponding to a potentially cured population. Further analysis revealed that pretreatment ctDNA variants serve as an essential MRD informed source. These data provide clinical insights for ctDNA-MRD detection.

Spatial downregulation of CD74 signatures may drive invasive component development in part-solid lung adenocarcinoma.

Pulmonary nodules with part-solid imaging features manifest during the progression from preinvasive to invasive lung adenocarcinoma. To define the spatial composition and evolutionary trajectories of early-stage lung adenocarcinoma, we combined spatial transcriptomics (ST) and pathological annotations from 20 part-solid nodules (PSNs), four of which were matched with single-cell RNA sequencing. Two malignant cell populations (MC1 and MC2) were identified, and a linear evolutionary relationship was observed. Compared to MC2, the pre-existing malignant MC1 exhibited a lower metastatic signature, corresponding to the preinvasive component (lepidic) on pathology and the ground glass component on PSN imaging. Higher immune infiltration was observed among MC1 regions in ST profiles, and further analysis revealed that macrophages may be involved in this process through the CD74 axis. This work provides deeper insights into the evolutionary process and spatial immune cell composition behind PSNs and highlights the mechanisms of immune escape behind this adenocarcinoma trajectory.

A theoretical study based on coherent perfect absorption and polarization separation in one-dimensional magnetized plasma photonic crystals.

This article presents a study on tunable narrowband coherent perfect absorption (CPA), which can be altered by adjusting the initial phase to the ranges of 1.03α-1.13α (with α = 2πc/d) and 1.29α-1.43α. The relative bandwidths of these ranges are determined to be 8.5% and 7.4%, respectively. The study utilizes the transfer matrix method for calculations of the largest CPA amplitudes within one-dimensional (1D) magnetized plasma photonic crystals (MPPCs) across two absorption bands, achieving a maximum of 0.99 and 0.98, respectively. In addition, the phase modulation and amplitude modulation characteristics of the CPA are also discussed, and the results show that its absorption amplitude can be gradually modulated from 0.08 to 0.99 by the former and from 0.60 to 0.98 by the latter. The external magnetic fields have also been shown to limit the CPA amplitude between 0.41 and 0.99 within one band and between 0.52 and 0.99 within another band. The study further highlights the effect of plasma frequency and dielectric layer thickness on coherent band shifts towards high or low frequencies. Notably, the article presents the multiband polarization separation properties of 1D MPPCs, with calculated transmittance differences between the TM and TE waves of up to 0.70 and 0.74 at 1.13α and 1.37α, respectively.

Neoadjuvant immunotherapy in patients with pulmonary lymphoepithelioma-like carcinoma.

OBJECTIVES: Neoadjuvant immunotherapy can be used to treat early-stage non-small-cell lung cancer; however, their effects on pulmonary lymphoepithelioma-like carcinomas (LELC) remain unclear. MATERIALS AND METHODS: Thirty-nine patients with stages I-III LELC were treated with chemotherapy (Chemo) or neoadjuvant immune-checkpoint inhibitors (ICIs) with or without chemo (IO) before radical-intent surgery. Short-term outcomes included objective response rate (ORR), major pathologic response (MPR), pathologic complete response (PCR), and event-free survival. For comparison, we used IO to treat 63 patients with pulmonary squamous cell carcinomas (SQC) and 47 with adenocarcinomas (ADC). Propensity score matching was analyzed to minimize bias. RESULTS: ORRs of the LELC-IO and LELC-Chemo groups were 62.5% and 42.9%, respectively (odds ratio, 2.2, 95% confidence interval, 0.423-11.678, p = 0.346). Seven (21.9%) and zero patients in LELC-IO and LELC-Chemo groups, respectively, reached PCR. MPR was identified in five (15.6%) of the 32 patients with LELC-IO. The 1-year progression-free survival rates were 96.9% and 71.4% in IO and Chemo groups, respectively (p > 0.05). However, no difference was observed in ORR, PCR, and MPR between LELC and SQC groups (ORR, 63.2% vs. 68.4%, p > 0.05; PCR, 21.1% vs. 47.4, p > 0.05; MPR, 42.1% vs. 57.9%, p > 0.05) and LELC and ADC groups (ORR, 58.8% vs. 41.2%, p > 0.05; PCR, 17.6% vs. 23.5%, p = 0.672; MPR, 29.4% vs. 47.1%, p > 0.05). The plasma Epstein-Barr virus (EBV) DNA level in a patient was altered posttreatment. CONCLUSION: Patients with LELC could be benefit from neoadjuvant immunotherapy. Distinct histological subtypes demonstrated comparable efficacy with respect to neoadjuvant immunotherapy.

Postoperative circulating tumor DNA can refine risk stratification in resectable lung cancer: results from a multicenter study.

Circulating tumor DNA (ctDNA) has potential as a promising biomarker for molecular residual disease (MRD) detection in lung cancer. As the next-generation sequencing standardized panel for ctDNA detection emerges, its clinical utility needs to be validated. We prospectively recruited 184 resectable lung cancer patients from four medical centers. Serial postoperative ctDNAs were analyzed by a standardized panel. A total of 427 postoperative plasma samples from 177 eligible patients were enrolled. ctDNA positivity after surgery was an independent predictor for disease recurrence and preceded radiological recurrence by a median of 6.6 months (range, 0.7-27.0 months). ctDNA-positive or -negative patients with tumors of any stage had similar disease-free survival (DFS). Patients who received targeted therapy had significantly improved DFS than those not receiving adjuvant therapy or receiving chemotherapy, regardless of baseline/preadjuvant ctDNA status. According to whether the ctDNA variants were detected in its matched tissue, they were classified into tissue derived and non-tissue derived. Patients with detectable postoperative ctDNA with tissue-derived mutations had comparable DFS with those with non-tissue-derived mutations. Collectively, we demonstrated that postoperative ctDNA has the potential to stratify prognosis and optimize tumor stage in resectable lung cancer. ctDNA variants not identified in tissue samples should be considered in MRD test.

PLEK2 and IFI6, representing mesenchymal and immune-suppressive microenvironment, predicts resistance to neoadjuvant immunotherapy in esophageal squamous cell carcinoma.

BACKGROUND: Immunotherapy has largely improved clinical outcome of patients with esophageal squamous cell carcinoma (ESCC). However, a proportion of patients still fail to benefit. Thus, biomarkers predicting therapeutic resistance and underlying mechanism needs to be investigated. METHODS: Transcriptomic profiling was applied in FFPE tissues from 103 ESCC patients, including surgical samples from 66 treatment-naïve patients with long-term follow-up, and endoscopic biopsies from 37 local advanced ESCC cases receiving neoadjuvant immunotherapy plus chemotherapy. Unsupervised clustering indicated an aggressive phenotype with mesenchymal character in 66 treatment-naïve samples. Univariant logistic regression was applied to identify candidate biomarkers potentially predicted resistance to neoadjuvant immunotherapy within the range of mesenchymal phenotype enriched genes. These biomarkers were further validated by immunohistochemistry. Putative mechanisms mediating immunotherapy resistance, as indicated by microenvironment and immune cell infiltration, were evaluated by transcriptomic data, and validated by multiplex immunofluorescence. RESULTS: PLEK2 and IFI6, highly expressed in mesenchymal phenotype, were identified as novel biomarkers relating to non-MPR in neoadjuvant immunotherapy cohort [PLEK2high, OR (95% CI): 2.15 (1.07-4.33), P = 0.032; IFI6high, OR (95% CI): 2.21 (1.16-4.23), P = 0.016). PLEK2high and IFI6 high ESCC patients (versus low expressed patients) further exhibit higher chance of non-major pathological remissions (90%, P = 0.004) in neoadjuvant immunotherapy cohort and high mortality (78.9%, P = 0.05), poor prognosis in retrospective cohort. PLEK2high/IFI6high ESCC recapitulated mesenchymal phenotype, characterized by extracellular matrix composition and matrix remodeling. In addition, PLEK2high or IFI6high ESCC displayed an immune-unfavored microenvironment, represented by positive correlating with regulatory T cells, Helper 2 T cell as well as less infiltration of B cells, effector T cells and mast cells. CONCLUSIONS: PLEK2 and IFI6 was discovered of first time to identify a distinct ESCC subpopulation cannot be benefited from neoadjuvant immunotherapy and present a poor survival, which putatively associated with mesenchymal and immune-suppressive microenvironment.

Identification of TCR rearrangements specific for genetic alterations in EGFR-mutated non-small cell lung cancer: results from the ADJUVANT-CTONG1104 trial.

Tumor response T cells, which have specific T cell receptor (TCR) rearrangements in tumor-infiltrating lymphocytes, determine their ability to interact with the mutation-derived neoantigens presented by antigen-presenting cells. Little is known about the genetic alterations related to specific TCR clones in non-small cell lung cancer (NSCLC) patients who have an epidermal growth factor receptor (EGFR) mutation. In this study, tumor tissues were collected from 101 patients with stage II/III resectable NSCLC with an EGFR mutation (57 patients were treated with gefitinib and 44 were treated with chemotherapy) in the ADJUVANT-CTONG1104 trial for high-throughput TCRß V region and exome sequencing. Ten clonal TCRs were associated with EGFR exon 19 deletion (del), EGFR exon 21 mutation (L858R), RB1 alteration, TP53 exon 4/5 missense mutation, TP53 nonsense mutation, or copy number gains in NKX2-1 and CDK4. Among the TCRs, there was frequent use of Vß20-1Jß2-3 specifically for EGFR exon 19 del or Vß9Jß2-1 specifically for EGFR exon 21 mutation (L858R), and these were significantly associated with favorable overall survival (OS) for NSCLC patients harboring EGFR exon 19 del or exon 21 L858R, particularly in the adjuvant gefitinib setting. Moreover, in comparison with the chemotherapy-preferable (CP) group, higher frequencies of Vß20-1Jß2-3 and Vß9Jß2-1 were found in the highly TKI-preferable (HTP) or TKI-preferable (TP) groups. Altogether, we identified ten TCR rearrangements specific for genetic alterations in NSCLC. Importantly, high abundance Vß20-1Jß2-3 or Vß9Jß2-1 may be an immune biomarker for guiding adjuvant gefitinib decisions for NSCLC patients harboring EGFR exon 19 del or EGFR exon 21 L858R.

The regularity of anatomical variations of dominant pulmonary segments in the right upper lobe.

BACKGROUND: Anatomical variations often pose challenges to pulmonary surgery. Previous studies have mainly described the frequencies of bronchovascular anatomical variations in pulmonary segments, but did not determine the differences between pulmonary segments and the regularity behind these anatomical variations. Here, we attempted to investigate the regularity of bronchovascular anatomical variations in different pulmonary segments. METHODS: Thin-slice enhanced computed tomography data of 800 cases from our center were included in this study. Digitalized three-dimensional virtual lung segmentation was done, the dominant and inferior lung segments of the right upper lobe were defined, and the regularity of anatomical variations was explored. RESULTS: The mean volume ratio of the anterior segment of the right upper lobe (39.6 ± 8.6%) was highest, and that of the posterior segment (28.6 ± 7.9%) was lowest. Therefore, the dominant-type segment (DS + SDS) was dominant in the anterior segment, accounting for 74.6% (597/800), and the inferior-type segment (SIS + IS) was dominant in the posterior segment of the right upper lobe, accounting for 71.5% of cases (573/800). During the transformation of dominant and inferior lung segments, the corresponding regularity of anatomical variations could be displayed. For example, with an increase in the volume of the anterior segment of the right upper lobe, the occurrence rate of the bifurcated type of bronchus (B1 + 2, B3), the "central vein type" and the involvement of the trunk inferior and ascending artery in the blood supply of anterior segment gradually increased. CONCLUSIONS: The existence of dominant segments will increase the diversity of anatomical variations and the complexity of pulmonary segmentectomy.

Investigation on the incidence and risk factors of lung cancer among Chinese hospital employees.

OBJECTIVE: In recent years, the lung cancer incidence has grown and the population is younger. We intend to find out the true detection rate of pulmonary nodules and the incidence of lung cancer in the population and search for the risk factors. METHOD: Hospital employees ≥40 years old who underwent low-dose computed tomography (CT) lung cancer screening from January 2019 to March 2022 were selected to record CT-imaging characteristics, pathology, staging, and questionnaires to investigate past history, smoking history, diet, mental health, etc. PM2.5 and radiation intake in radiation-related occupation received monitoring in hospital. RESULT: The detection rate of suspicious pulmonary nodules was 9.1% (233/2552), and the incidence rate of lung cancer (including adenocarcinoma in situ) was 4.0% (103/2552). Morbidity among doctors, nurses, technicians, administers, and logistics was no difference (p = 0.184), but higher in women than in men (4.7% vs 2.4% p = 0.002). The invasiveness increased with age and CT density of nodules (p = 0.018). The relationship between lung cancer morbidity and PM2.5 was not clear (p = 0.543); and no lung cancer has been found in employees related ionizing radiation. CONCLUSION: The high screening rate has brought about a high incidence of lung cancer. At present, the risk factor analysis of lung cancer based on small samples cannot find the direct cause. Most of the ground glass opacity (GGO)s detected by LDCT screening are indolent, but there are also rapidly progressive lung cancer. A predictive model to identify active and indolent GGO is necessary.

Perioperative targeted therapy for oncogene-driven NSCLC.

Targeted therapy has stepped into the perioperative treatment arena and launched a radical revolution in the treatment of early-stage oncogene-driven non-small-cell lung cancer (NSCLC). A series of practice-changing clinical trials has enriched the therapeutic perspectives of potentially curable NSCLC. While the CTONG1104 trial took the first step in investigating the adjuvant gefitinib - a first-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), for the treatment of resected EGFR-mutated NSCLC - the subsequent ADAURA study marked adjuvant osimertinib as the standard of care for resected EGFR-mutant NSCLC. Other targeted agents matched for ALK, ROS1, NTRK, BRAF V600, and RET molecular alterations are also currently being evaluated in the adjuvant and neoadjuvant settings, and there is an urgent need to study biomarker selection, optimal duration, and paradigm making. All these efforts are intended to hit the same target, which is to treat patients on a more personalized level. We review herein the recent major breakthroughs in perioperative targeted therapy for oncogene-driven NSCLC, focusing especially on data from published clinical trials. We discuss challenges from surgical, pathological, and oncological perspectives, and provide recommended strategies for the clinical management of early-stage NSCLC patients.

Longitudinal Undetectable Molecular Residual Disease Defines Potentially Cured Population in Localized Non-Small Cell Lung Cancer.

The efficacy and potential limitations of molecular residual disease (MRD) detection urgently need to be fully elucidated in a larger population of non-small cell lung cancer (NSCLC). We enrolled 261 patients with stages I to III NSCLC who underwent definitive surgery, and 913 peripheral blood samples were successfully detected by MRD assay. Within the population, only six patients (3.2%) with longitudinal undetectable MRD recurred, resulting in a negative predictive value of 96.8%. Longitudinal undetectable MRD may define the patients who were cured. The peak risk of developing detectable MRD was approximately 18 months after landmark detection. Correspondingly, the positive predictive value of longitudinal detectable MRD was 89.1%, with a median lead time of 3.4 months. However, brain-only recurrence was less commonly detected by MRD (n = 1/5, 20%). Further subgroup analyses revealed that patients with undetectable MRD might not benefit from adjuvant therapy. Together, these results expound the value of MRD in NSCLC. SIGNIFICANCE: This study confirms the prognostic value of MRD detection in patients with NSCLC after definitive surgery, especially in those with longitudinal undetectable MRD, which might represent the potentially cured population regardless of stage and adjuvant therapy. Moreover, the risk of developing detectable MRD decreased stepwise after 18 months since landmark detection. This article is highlighted in the In This Issue feature, p. 1599.

Identification of heritable rare variants associated with early-stage lung adenocarcinoma risk.

Background: In East Asia, the number of patients with adenocarcinoma, especially those presenting with ground-glass nodules (GGNs), is gradually increasing. Family aggregation of pulmonary GGNs is not uncommon; however, genetic predisposition in these patients remains poorly understood and identification of genes involved in the cause of these early-stage lung cancers might contribute to understanding of the underlying mechanisms and potential prevention strategies. Methods: Fifty patients with early-stage lung adenocarcinoma (LUAD) presenting as GGNs and a first-degree family history of lung cancer (FHLC) from 34 independent families were enrolled into this study. Germline mutations of these patients were analyzed with whole exome sequencing (WES) and compared with age- and sex-matched 39 patients with sporadic lung cancer and 689 local healthy people. We used a stepwise variant filtering strategy, gene-based burden testing, and enrichment analysis to investigate rare but potentially pathogenic heritable mutations. Somatic tumor mutations were analyzed to consolidate germline findings. Results: In total, 1,571 single nucleotide variants (SNVs) and 238 frameshifts with a minor allele frequency (MAF) <0.01, which were rare, recurrent, and potentially damaging candidates, were finally identified through the filtering in the GGN cohort. Pathway analysis showed the extracellular matrix to be the top dysregulated pathway. Gene-based burden testing of these highly disruptive risk-conferring heritable variants showed that MSH5 [odds ratio (OR), 9.28, 95% confidence interval (CI): 2.49-35.87], MMP9 (OR, 8.11, 95% CI: 2.22-28.43), and CYP2D6 (OR, 8.09, 95% CI: 2.68-24.92) were significantly enriched in our cohort (P<0.05). The number of rare damaging germline variants in non-smoking patients was significantly higher than that of smoking-affected patients (Spearman's ρ=-0.39, P=0.02). Conclusions: Heritable, potentially deleterious, and rare candidate variants of MSH5, MMP9 and CYP2D6 were significantly associated with early-stage LUAD presenting with GGNs. Nonsmoking patients likely have a higher genetic predisposition to this type of cancer than smoking-affected patients. These results have extended our understanding of the underlying mechanisms of early-stage LUAD.

Intratumoral genetic and immune microenvironmental heterogeneity in T4N0M0 (diameter ≥ 7 cm) non-small cell lung cancers.

BACKGROUND: Starting with low metastatic capability, T4N0M0 (diameter ≥ 7 cm) non-small cell lung cancers (NSCLCs) constitute a unique tumor subset, as with a large tumor size but no regional or distant metastases. We systematically investigated intratumoral heterogeneity, clonal structure, chromosomal instability (CIN), and immune microenvironment in T4N0M0 (≥7 cm) NSCLCs. METHODS: Whole-exome sequencing, RNA sequencing, and multiplex immunohistochemistry (mIHC) staining were conducted to analyze 24 spatially segregated tumor samples from eight patients who were pathologically diagnosed with T4N0M0 (diameter ≥ 7 cm) NSCLCs. The adjacent normal tissues and peripheral blood served as controls. RESULTS: In total, 35.2% of mutations and 91.1% of somatic copy number alterations were classified as subclonal events, which exhibited widespread genetic intratumoral heterogeneity. In contrast, a low degree of CIN was observed. None of the patients had genome doubling. The burden of loss of heterozygosity, aneuploidy, and the genome instability index of these tumors were significantly lower than those in the TRACERx cohort. Expression profiles revealed significantly upregulated expression of cell division-related signals and the G2/M checkpoint pathway. In addition, a similar expression pattern of the immune microenvironment was observed in different regions of the tumor, which was confirmed by mIHC profiles. CONCLUSIONS: Our study indicates the presence of intratumoral genetic heterogeneity and immune microenvironmental heterogeneity features in T4N0M0 NSCLCs, and the low degree of CIN may be related to the low metastatic capability.

Prediction of unfavourable response to checkpoint blockade in lung cancer patients through an integrated tumour-immune expression score.

BACKGROUND: Treatment by immune checkpoint blockade (ICB) provides a remarkable survival benefit for multiple cancer types. However, disease aggravation occurs in a proportion of patients after the first couple of treatment cycles. METHODS: RNA sequencing data was retrospectively collected. 6 tumour-immune related features were extracted and combined to build a lung cancer-specific predictive model to distinguish responses as progression disease (PD) or non-PD. This model was trained by 3 public pan-cancer datasets and a lung cancer cohort from our institute, and generated a lung cancer-specific integrated gene expression score, which we call LITES. It was finally tested in another lung cancer dataset. RESULTS: LITES is a promising predictor for checkpoint blockade (area under the curve [AUC]=0.86), superior to traditional biomarkers. It is independent of PD-L1 expression and tumour mutation burden. The sensitivity and specificity of LITES was 85.7% and 70.6%, respectively. Progression free survival (PFS) was longer in high-score group than in low-score group (median PFS: 6.0 vs. 2.4 months, hazard ratio=0.45, P=0.01). The mean AUC of 6 features was 0.70 (range=0.61-0.75), lower than in LITES, indicating that the combination of features had synergistic effects. Among the genes identified in the features, patients with high expression of NRAS and PDPK1 tended to have a PD response (P=0.001 and 0.01, respectively). Our model also functioned well for patients with advanced melanoma and was specific for ICB therapy. CONCLUSIONS: LITES is a promising biomarker for predicting an impaired response in lung cancer patients and for clarifying the biological mechanism underlying ICB therapy.

MET amplification identified by next-generation sequencing and its clinical relevance for MET inhibitors.

BACKGROUND: MET amplification plays an important role in the development of non-small-cell lung cancer (NSCLC) either de novo or in resistance to epidermal growth factor receptor tyrosine-kinase inhibitor (EGFR-TKI) settings. Fluorescence in situ hybridization (FISH) is the standard method for MET amplification. With more and more discoveries of oncogenic driver genes, next-generation sequencing (NGS) plays a significant role in precision oncology. Meanwhile, the role of NGS in MET amplification remains uncertain. METHODS: Forty patients diagnosed with advanced NSCLC were included. FISH and NGS were conducted prior to MET inhibitors treatment. MET amplification by FISH was defined as a MET/CEP7 ratio of > 2.0 and/or copy number (CN) > 5. MET amplification by NGS was defined as gene copy number (GCN) ≥ 5. RESULTS: The concordance rate among FISH and NGS was 62.5% (25/40). MET amplification identified by FISH showed the optimal predictive value. The partial response (PR) rate was 68.0% (17/25 with MET amplification) vs. 6.7% (1/15 without MET amplification); the median progression-free survival (PFS) was 5.4 months versus 1.0 months (P < 0.001). MET amplification identified by NGS failed to distinguish significant clinical outcomes. The PR rate was 60.0% (6/10, with MET GCN ≥ 5) vs. 40.0% (12/30, with MET GCN < 5); the median PFS was 4.8 months vs. 2.2 months (P = 0.357). The PR rate was 68.8% (11/16) and the median PFS was 4.8 months in patients with focal amplification by NGS. CONCLUSIONS: MET amplification identified by FISH remains the optimal biomarker to identify suitable candidates for MET-TKI therapy. In comparison, amplification identified by NGS seems not as robust to be effective predictive biomarker. Further exploration is needed regarding the focal amplification by NGS in predicting the efficacy.