Elucidating the genomic architecture of Asian EGFR-mutant lung adenocarcinoma through multi-region exome sequencing

Metabolic heterogeneity in tumor cells impacts immunology in lung squamous cell carcinoma

Metabolic processes are crucial in immune regulation, yet the impact of metabolic heterogeneity on immunological functions remains unclear. Integrating metabolomics into immunology allows the exploration of the interactions of multilayered features in the biological system and the molecular regulatory mechanism of these features. To elucidate such insight in lung squamous cell carcinoma (LUSC), we analyzed 106 LUSC tumor tissues. We performed high-resolution matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) to obtain spatial metabolic profiles, and immunohistochemistry to detect tumor-infiltrating T lymphocytes (TILs). Unsupervised k-means clustering and Simpson's diversity index were employed to assess metabolic heterogeneity, identifying five distinct metabolic tumor subpopulations. Our findings revealed that TILs are specifically associated with metabolite distributions, not randomly distributed. Integrating a validation cohort, we found that heterogeneity-correlated metabolites interact with CD8+ TIL-associated genes, affecting survival. High metabolic heterogeneity was linked to worse survival and lower TIL levels. Pathway enrichment analyses highlighted distinct metabolic pathways in each subpopulation and their potential responses to chemotherapy. This study uncovers the significant impact of metabolic heterogeneity on immune functions in LUSC, providing a foundation for tailoring therapeutic strategies.

Clonal driver neoantigen loss under EGFR TKI and immune selection pressures

Neoantigen vaccines are under investigation for various cancers, including epidermal growth factor receptor (EGFR)-driven lung cancers1,2. We tracked the phylogenetic history of an EGFR mutant lung cancer treated with erlotinib, osimertinib, radiotherapy and a personalized neopeptide vaccine (NPV) targeting ten somatic mutations, including EGFR exon 19 deletion (ex19del). The ex19del mutation was clonal, but is likely to have appeared after a whole-genome doubling (WGD) event. Following osimertinib and NPV treatment, loss of the ex19del mutation was identified in a progressing small-cell-transformed liver metastasis. Circulating tumour DNA analyses tracking 467 somatic variants revealed the presence of this EGFR wild-type clone before vaccination and its expansion during osimertinib/NPV therapy. Despite systemic T cell reactivity to the vaccine-targeted ex19del neoantigen, the NPV failed to halt disease progression. The liver metastasis lost vaccine-targeted neoantigens through chromosomal instability and exhibited a hostile microenvironment, characterized by limited immune infiltration, low CXCL9 and elevated M2 macrophage levels. Neoantigens arising post-WGD were more likely to be absent in the progressing liver metastasis than those occurring pre-WGD, suggesting that prioritizing pre-WGD neoantigens may improve vaccine design. Data from the TRACERx 421 cohort3 provide evidence that pre-WGD mutations better represent clonal variants, and owing to their presence at multiple copy numbers, are less likely to be lost in metastatic transition. These data highlight the power of phylogenetic disease tracking and functional T cell profiling to understand mechanisms of immune escape during combination therapies.

Proteogenomic analysis reveals non-small cell lung cancer subtypes predicting chromosome instability, and tumor microenvironment

Non-small cell lung cancer (NSCLC) is histologically classified into lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LSCC). However, some tumors are histologically ambiguous and other pathophysiological features or microenvironmental factors may be more prominent. Here we report integrative multiomics analyses using data for 229 patients from a Korean NSCLC cohort and 462 patients from previous multiomics studies. Histological examination reveals five molecular subtypes, one of which is a NSCLC subtype with PI3K-Akt pathway upregulation, showing a high proportion of metastasis and poor survival outcomes regardless of any specific NSCLC histology. Proliferative subtypes are present in LUAD and LSCC, which show strong associations with whole genome doubling (WGD) events. Comprehensive characterization of the immune microenvironment reveals various immune cell compositions and neoantigen loads across molecular subtypes, which predicting different prognoses. Immunological subtypes exhibit a hot tumor-enriched state and a higher efficacy of adjuvant therapy.

Advancements in fourth-generation EGFR TKIs in EGFR-mutant NSCLC: Bridging biological insights and therapeutic development

Third-generation EGFR tyrosine kinase inhibitor (TKIs) have revolutionized the treatment landscape for patients with non-small cell lung cancer (NSCLC) harboring EGFR activating mutations, with improved long-term outcomes compared to first-generation TKIs. Nevertheless, disease progression inevitably occurs, limiting osimertinib long-term efficacy. Indeed, the molecular biology underlying acquired resistance to first-line osimertinib is multifaceted and includes the emergence of on-target and off-target alterations. EGFR-C797S mutation represents the most frequent mechanism of on-target resistance and hinders drug binding to the target site. EGFR-independent resistance includes the activation of alternative signaling pathways, such as MET amplification and HER2 mutations, and histological transformation. In this setting, chemotherapy is the current therapeutic option, with modest clinical outcomes. Therefore, the development of novel therapeutic strategies to overcome resistance to osimertinib is a major challenge. In this setting, fourth-generation TKIs are emerging as an interesting therapeutic option to overcome on-target resistance. Preclinical drug development has led to the discovery of thiazole-amid inhibitors, which activity is mediated by the allosteric inhibition of EGFR, resulting in high specificity towards mutant-EGFR. Early phase 1/2 clinical trials are ongoing to elucidate their activity also in the clinical setting. Aim of this review is to provide a state-of-the-art analysis on preclinical development of fourth-generation EGFR-TKIs and promising preliminary clinical data.

Super multiple primary lung cancers harbor high-frequency BRAF and low-frequency EGFR mutations in the MAPK pathway

The incidence of multiple primary lung cancer (MPLC) is increasing, with some of our surgical patients exhibiting numerous lesions. We defined lung cancer with five or more primary lesions as super MPLCs. Elucidating the genomic characteristics of this special MPLC subtype can help reduce disease burden and understand tumor evolution. In our cohort of synchronous super early-stage MPLCs (PUMCH-ssesMPLC), whole-exome sequencing on 130 resected malignant specimens from 18 patients provided comprehensive super-MPLC genomic landscapes. Mutations are enriched in PI3k-Akt and MAPK pathways. Their BRAF mutation frequency (31.5%) is significantly higher than MPLC with fewer lesions and early-stage single-lesion cancer, while EGFR mutations are significantly fewer (13.8%). As lesion counts increase, BRAF mutations gradually become dominant. Also, invasive lesions more tend to have classic super-MPLC mutation patterns. High-frequency BRAF mutations, especially Class II, and low-frequency EGFR mutations could be a reason for the limited effectiveness of targeted therapy in super-MPLC patients.

Multi-ancestry GWAS meta-analyses of lung cancer reveal susceptibility loci and elucidate smoking-independent genetic risk

Lung cancer remains the leading cause of cancer mortality, despite declining smoking rates. Previous lung cancer GWAS have identified numerous loci, but separating the genetic risks of lung cancer and smoking behavioral susceptibility remains challenging. Here, we perform multi-ancestry GWAS meta-analyses of lung cancer using the Million Veteran Program cohort (approximately 95% male cases) and a previous study of European-ancestry individuals, jointly comprising 42,102 cases and 181,270 controls, followed by replication in an independent cohort of 19,404 cases and 17,378 controls. We then carry out conditional meta-analyses on cigarettes per day and identify two novel, replicated loci, including the 19p13.11 pleiotropic cancer locus in squamous cell lung carcinoma. Overall, we report twelve novel risk loci for overall lung cancer, lung adenocarcinoma, and squamous cell lung carcinoma, nine of which are externally replicated. Finally, we perform PheWAS on polygenic risk scores for lung cancer, with and without conditioning on smoking. The unconditioned lung cancer polygenic risk score is associated with smoking status in controls, illustrating a reduced predictive utility in non-smokers. Additionally, our polygenic risk score demonstrates smoking-independent pleiotropy of lung cancer risk across neoplasms and metabolic traits.

Correcting for Observation Bias in Cancer Progression Modeling

Tumor progression is driven by the accumulation of genetic alterations, including both point mutations and copy number changes. Understanding the temporal sequence of these events is crucial for comprehending the disease but is not directly discernible from cross-sectional genomic data. Cancer progression models, including Mutual Hazard Networks (MHNs), aim to reconstruct the dynamics of tumor progression by learning the causal interactions between genetic events based on their co-occurrence patterns in cross-sectional data. Here, we highlight a commonly overlooked bias in cross-sectional datasets that can distort progression modeling. Tumors become clinically detectable when they cause symptoms or are identified through imaging or tests. Detection factors, such as size, inflammation (fever, fatigue), and elevated biochemical markers, are influenced by genomic alterations. Ignoring these effects leads to "conditioning on a collider" bias, where events making the tumor more observable appear anticorrelated, creating false suppressive effects or masking promoting effects among genetic events. We enhance MHNs by incorporating the effects of genetic progression events on the inclusion of a tumor in a dataset, thus correcting for collider bias. We derive an efficient tensor formula for the likelihood function and apply it to two datasets from the MSK-IMPACT study. In colon adenocarcinoma, we observe a significantly higher rate of clinical detection for TP53-positive tumors, while in lung adenocarcinoma, the same is true for EGFR-positive tumors. Compared to classical MHNs, this approach eliminates several spurious suppressive interactions and uncovers multiple promoting effects.

Decision model for durable clinical benefit from front- or late-line immunotherapy alone or with chemotherapy in non-small cell lung cancer

BACKGROUND

Predictive biomarkers and models of immune checkpoint inhibitors (ICIs) have been extensively studied in non-small cell lung cancer (NSCLC). However, evidence for many biomarkers remains inconclusive, and the opaqueness of machine learning models hinders practicality. We aimed to provide compelling evidence for biomarkers and develop a transparent decision tree model.

METHODS

We consolidated data from 3,288 ICI-treated patients with NSCLC across real-world multicenter, public cohorts and the Choice-01 trial (ClinicalTrials.gov: NCT03856411). Over 50 features were examined for predicting durable clinical benefits (DCBs) from ICIs. Noteworthy biomarkers were identified to establish a decision tree model. Additionally, we explored the tumor microenvironment and peripheral CD8+ programmed death-1 (PD-1)+ T cell receptor (TCR) profiles.

FINDINGS

Multivariate logistic regression analysis identified tumor histology, PD-ligand 1 (PD-L1) expression, tumor mutational burden, line, and regimen of ICI treatment as significant factors. Mutation subtypes of EGFR, KRAS, KEAP1, STK11, and disruptive TP53 mutations were associated with DCB. The decision tree (DT10) model, using the ten clinicopathological and genomic markers, showed superior performance in predicting DCB in the training set (area under the curve [AUC] = 0.82) and consistently outperformed other models in test sets. DT10-predicted-DCB patients manifested longer survival, an enriched inflamed tumor immune phenotype (67%), and higher peripheral TCR diversity, whereas the DT10-predicted-NDB (non-durable benefit) group showed an enriched desert immune phenotype (86%) and higher peripheral TCR clonality.

CONCLUSIONS

The model effectively predicted DCB after front-/subsequent-line ICI treatment, with or without chemotherapy, for squamous and non-squamous lung cancer, offering clinicians valuable insights into efficacy prediction using cost-effective variables.

FUNDING

This study was supported by the National Key R&D Program of China.

Exploring the immune landscape and drug prediction of an M2 tumor-associated macrophage-related gene signature in EGFR-negative lung adenocarcinoma

BACKGROUND

Improving immunotherapy efficacy for EGFR-negative lung adenocarcinoma (LUAD) patients remains a critical challenge, and the therapeutic effect of immunotherapy is largely determined by the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are the top-ranked immune infiltrating cells in the TME, and M2-TAMs exert potent roles in tumor promotion and chemotherapy resistance. An M2-TAM-based prognostic signature was constructed by integrative analysis of single-cell RNA-seq (scRNA-seq) and bulk RNA-seq data to reveal the immune landscape and select drugs in EGFR-negative LUAD.

METHODS

M2-TAM-based biomarkers were obtained from the intersection of bulk RNA-seq data and scRNA-seq data. After consensus clustering of EGFR-negative LUAD into different clusters based on M2-TAM-based genes, we compared the prognosis, clinical features, estimate scores, immune infiltration, and checkpoint genes among the clusters. Next, we combined univariate Cox and LASSO regression analyses to establish an M2-TAM-based prognostic signature.

RESULTS

CCL20, HLA-DMA, HLA-DRB5, KLF4, and TMSB4X were verified as prognostic M2-like TAM-related genes by univariate Cox and LASSO regression analyses. IPS and TMB analyses revealed that the high-risk group responded better to common immunotherapy.

CONCLUSION

The study shows the potential of the M2-like TAM-related gene signature in EGFR-negative LUAD, explores the immune landscape based on M2-like TAM-related genes, and predict immunotherapy response of patients with EGFR-negative LUAD, providing a new insight for individualized treatment.

Modeling metastatic progression from cross-sectional cancer genomics data

MOTIVATION

Metastasis formation is a hallmark of cancer lethality. Yet, metastases are generally unobservable during their early stages of dissemination and spread to distant organs. Genomic datasets of matched primary tumors and metastases may offer insights into the underpinnings and the dynamics of metastasis formation.

RESULTS

We present metMHN, a cancer progression model designed to deduce the joint progression of primary tumors and metastases using cross-sectional cancer genomics data. The model elucidates the statistical dependencies among genomic events, the formation of metastasis, and the clinical emergence of both primary tumors and their metastatic counterparts. metMHN enables the chronological reconstruction of mutational sequences and facilitates estimation of the timing of metastatic seeding. In a study of nearly 5000 lung adenocarcinomas, metMHN pinpointed TP53 and EGFR as mediators of metastasis formation. Furthermore, the study revealed that post-seeding adaptation is predominantly influenced by frequent copy number alterations.

AVAILABILITY AND IMPLEMENTATION

All datasets and code are available on GitHub at https://github.com/cbg-ethz/metMHN.

Oncogene-Driven Non-Small Cell Lung Cancers in Patients with a History of Smoking Lack Smoking-Induced Mutations

Non-small cell lung cancers (NSCLC) in nonsmokers are mostly driven by mutations in the oncogenes EGFR, ERBB2, and MET and fusions involving ALK and RET. In addition to occurring in nonsmokers, alterations in these "nonsmoking-related oncogenes" (NSRO) also occur in smokers. To better understand the clonal architecture and genomic landscape of NSRO-driven tumors in smokers compared with typical-smoking NSCLCs, we investigated genomic and transcriptomic alterations in 173 tumor sectors from 48 NSCLC patients. NSRO-driven NSCLCs in smokers and nonsmokers had similar genomic landscapes. Surprisingly, even in patients with prominent smoking histories, the mutational signature caused by tobacco smoking was essentially absent in NSRO-driven NSCLCs, which was confirmed in two large NSCLC data sets from other geographic regions. However, NSRO-driven NSCLCs in smokers had higher transcriptomic activities related to the regulation of the cell cycle. These findings suggest that, whereas the genomic landscape is similar between NSRO-driven NSCLC in smokers and nonsmokers, smoking still affects the tumor phenotype independently of genomic alterations.

SIGNIFICANCE

Non-small cell lung cancers driven by nonsmoking-related oncogenes do not harbor genomic scars caused by smoking regardless of smoking history, indicating that the impact of smoking on these tumors is mainly nongenomic.

Whole-genome doubling is a double-edged sword: the heterogeneous role of whole-genome doubling in various cancer types

Whole-genome doubling (WGD), characterized by the duplication of an entire set of chromosomes, is commonly observed in various tumors, occurring in approximately 30-40% of patients with different cancer types. The effect of WGD on tumorigenesis varies depending on the context, either promoting or suppressing tumor progression. Recent advances in genomic technologies and large-scale clinical investigations have led to the identification of the complex patterns of genomic alterations underlying WGD and their functional consequences on tumorigenesis progression and prognosis. Our comprehensive review aims to summarize the causes and effects of WGD on tumorigenesis, highlighting its dualistic influence on cancer cells. We then introduce recent findings on WGD-associated molecular signatures and genetic aberrations and a novel subtype related to WGD. Finally, we discuss the clinical implications of WGD in cancer subtype classification and future therapeutic interventions. Overall, a comprehensive understanding of WGD in cancer biology is crucial to unraveling its complex role in tumorigenesis and identifying novel therapeutic strategies. [BMB Reports 2024; 57(3): 125-134].

Co-Occurring Alterations in Multiple Tumor Suppressor Genes Are Associated With Worse Outcomes in Patients With EGFR-Mutant Lung Cancer

INTRODUCTION

Patients with metastatic EGFR-mutant NSCLC inevitably have disease progression while on tyrosine kinase inhibitor (TKI) therapy. Co-occurring tumor suppressor gene (TSG) alterations have been associated with poor outcomes, however, detailed analyses of their impact on patient outcomes are limited.

METHODS

Patients with EGFR-mutant NSCLC treated with EGFR TKIs who had tumor genomic profiling were included. Alterations in TP53 and five additional TSGs (RB1, NF1, ARID1A, BRCA1, and PTEN) were used to stratify the cohort into the following three subgroups: patients with tumors harboring a TP53 mutation plus a mutation in at least one additional TSG (TP53mut/TSGmut), those having a TP53 mutation without additional TSG mutations (TP53mut/TSGwt), and those with TP53wt. Patient characteristics and clinical outcomes were assessed in two independent cohorts.

RESULTS

A total of 101 patients from the Yale Cancer Center and 182 patients from the American Association for Cancer Research Project GENIE database were included. In the Yale cohort, TP53 mutations were identified in 65 cases (64%), of which 23 were TP53mut/TSGmut and 42 were TP53mut/TSGwt. Although the presence of a TP53 mutation was associated with worse outcomes, the additional TSG alteration in TP53mut tumors identified a subset of patients associated with particularly aggressive disease and inferior clinical outcome in both the Yale and the GENIE cohorts. Specifically, in the Yale cohort for patients receiving first-line TKIs, those with TP53mut/TSGmut tumors had shorter progression-free survival (PFS) and overall survival (OS) than TP53mut/TSGwt (PFS: hazard ratio [HR] = 2.03, confidence interval [CI]: 1.12-3.69, p < 0.01, OS: HR = 1.58, CI: 0.82-3.04, p = 0.12) or TP53wt cases (PFS: HR 2.4, CI: 1.28-4.47, p < 0.001, OS: HR = 2.54, CI: 1.21-5.34, p < 0.005). Inferior outcomes in patients with TP53mut/TSGmut tumors were also found in those receiving osimertinib as second-line therapy. Similar findings were seen in patients in the GENIE cohort.

CONCLUSIONS

Patients with TP53mut/TSGmut tumors represent a patient subgroup characterized by an aggressive disease phenotype and inferior outcomes on EGFR TKIs. This information is important for understanding the biological underpinnings of differential outcomes with TKI treatment and has implications for identifying patients who may benefit from additional therapeutic interventions beyond osimertinib monotherapy.

Perioperative Treatment Strategies in EGFR-Mutant Early-Stage NSCLC: Current Evidence and Future Challenges

Treatment with 3 years of adjuvant osimertinib is considered a new standard in patients with completely resected stage I to IIIA NSCLC harboring a common sensitizing EGFR mutation. This therapeutic approach significantly prolonged the disease-free survival and the overall survival versus placebo and revealed a significant role in preventing the occurrence of brain metastases. However, many unanswered questions remain, including the optimal duration of this therapy, whether all patients benefit from adjuvant osimertinib, and the role of adjuvant chemotherapy in this population. Indeed, there is a renewed interest in neoadjuvant strategies with targeted therapies in resectable NSCLC harboring oncogenic drivers. In light of these considerations, we discuss the past and current treatment options, and the clinical challenges that should be addressed to optimize the treatment outcomes in this patient population.

Structural Racism and Lung Cancer Risk: A Scoping Review

Importance

Structural racism is associated with persistent inequities in health and health outcomes in the US for racial and ethnic minority groups. This review summarizes how structural racism contributes to differential population-level exposure to lung cancer risk factors and thus disparate lung cancer risk across different racial and ethnic groups.

Observations

A scoping review was conducted focusing on structural racism and lung cancer risk for racial and ethnic minority groups. The domains of structural racism evaluated included housing and built environment, occupation and employment, health care, economic and educational opportunity, private industry, perceived stress and discrimination, and criminal justice involvement. The PubMed, Embase, and MedNar databases were searched for English-language studies in the US from January 1, 2010, through June 30, 2022. The review demonstrated that racial and ethnic minority groups are more likely to have environmental exposures to air pollution and known carcinogens due to segregation of neighborhoods and poor housing quality. In addition, racial and ethnic minority groups were more likely to have exposures to pesticides, silica, and asbestos secondary to higher employment in manual labor occupations. Furthermore, targeted marketing and advertisement of tobacco products by private industry were more likely to occur in neighborhoods with more racial and ethnic minority groups. In addition, poor access to primary care services and inequities in insurance status were associated with elevated lung cancer risk among racial and ethnic minority groups. Lastly, inequities in tobacco use and cessation services among individuals with criminal justice involvement had important implications for tobacco use among Black and Hispanic populations.

Conclusions and Relevance

The findings suggest that structural racism must be considered as a fundamental contributor to the unequal distribution of lung cancer risk factors and thus disparate lung cancer risk across different racial and ethnic groups. Additional research is needed to better identify mechanisms contributing to inequitable lung cancer risk and tailor preventive interventions.

Clinical Impact of Genomic and Pathway Alterations in Stage I EGFR-Mutant Lung Adenocarcinoma

PURPOSE

We investigated the clinical impact of genomic and pathway alterations in stage I epidermal growth factor receptor (EGFR)-mutant lung adenocarcinomas, which have a high recurrence rate despite complete surgical resection.

MATERIALS AND METHODS

Out of the initial cohort of 257 patients with completely resected stage I EGFR-mutant lung adenocarcinoma, tumor samples from 105 patients were subjected to analysis using large-panel next-generation sequencing. We analyzed 11 canonical oncogenic pathways and determined the number of pathway alterations (NPA). Survival analyses were performed based on co-occurring alterations and NPA in three patient groups: all patients, patients with International Association for the Study of Lung Cancer (IASLC) pathology grade 2, and patients with recurrent tumors treated with EGFR-tyrosine kinase inhibitor (TKI).

RESULTS

In the univariate analysis, pathological stage, IASLC grade, TP53 mutation, NPA, phosphoinositide 3-kinase pathway, p53 pathway, and cell cycle pathway exhibited significant associations with worse recurrence-free survival (RFS). Moreover, RPS6KB1 or EGFR amplifications were linked to a poorer RFS. Multivariate analysis revealed that pathologic stage, IASLC grade, and cell cycle pathway alteration were independent poor prognostic factors for RFS (p=0.002, p < 0.001, and p=0.006, respectively). In the grade 2 subgroup, higher NPA was independently associated with worse RFS (p=0.003). Additionally, in patients with recurrence treated with EGFR-TKIs, co-occurring TP53 mutations were linked to shorter progression-free survival (p=0.025).

CONCLUSION

Genomic and pathway alterations, particularly cell cycle alterations, high NPA, and TP53 mutations, were associated with worse clinical outcomes in stage I EGFR-mutant lung adenocarcinoma. These findings may have implications for risk stratification and the development of new therapeutic strategies in early-stage EGFR-mutant lung cancer patients.

CDK4/6 signaling attenuates the effect of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in EGFR-mutant non-small cell lung cancer

Background

Epidermal growth factor receptor (EGFR) mutations, such as exon 19 deletion and exon 21 L858R, are driver oncogenes of non-small cell lung cancer (NSCLC), with EGFR tyrosine kinase inhibitors (TKIs) being effective against EGFR-mutant NSCLC. However, the efficacy of EGFR-TKIs is transient and eventually leads to acquired resistance. Herein, we focused on the significance of cell cycle factors as a mechanism to attenuate the effect of EGFR-TKIs in EGFR-mutant NSCLC before the emergence of acquired resistance.

Methods

Using several EGFR-mutant cell lines, we investigated the significance of cell cycle factors to attenuate the effect of EGFR-TKIs in EGFR-mutant NSCLC.

Results

In several EGFR-mutant cell lines, certain cancer cells continued to proliferate without EGFR signaling, and the cell cycle regulator retinoblastoma protein (RB) was not completely dephosphorylated. Further inhibition of phosphorylated RB with cyclin-dependent kinase (CDK) 4/6 inhibitors, combined with the EGFR-TKI osimertinib, enhanced G0/G1 cell cycle accumulation and growth inhibition of the EGFR-mutant NSCLC in both in vitro and in vivo models. Furthermore, residual RB phosphorylation without EGFR signaling was maintained by extracellular signal-regulated kinase (ERK) signaling, and the ERK inhibition pathway showed further RB dephosphorylation.

Conclusions

Our study demonstrated that the CDK4/6-RB signal axis, maintained by the MAPK pathway, attenuates the efficacy of EGFR-TKIs in EGFR-mutant NSCLC, and targeting CDK4/6 enhances this efficacy. Thus, combining CDK4/6 inhibitors and EGFR-TKI could be a novel treatment strategy for TKI-naïve EGFR-mutant NSCLC.

Concordance of Abundance for Mutational EGFR and Co-Mutational TP53 with Efficacy of EGFR-TKI Treatment in Metastatic Patients with Non-Small-Cell Lung Cancer

The present study aimed to investigate the influence of the mutation abundance of the epidermal growth factor receptor (EGFR) and its co-mutation with TP53 on the therapeutic efficacy of tyrosine kinase inhibitor (TKI) treatment in patients with metastatic lung adenocarcinoma (LUAD). In total, 130 patients (January 2018-September 2022) with metastatic LUAD from the Second Affiliated Hospital of Zhejiang University were included. Kaplan-Meier analysis was performed to measure the duration of drug application (DDA) and the log-rank test was used to compare differences. Univariate and multivariate analyses of Cox proportional hazard regression models were used to evaluate the association between the relevant clinicopathological factors and DDA. Hazard ratios with 95% confidence intervals were also calculated. Among the 130 patients who were treated with first-generation EGFR-TKIs, 86 showed high-EGFR mutation abundance (>22.0%) and 44 showed low-EGFR mutation abundance (≤22.0%). Patients in the high-EGFR group had a greater DDA than those in the low-EGFR group (p < 0.05). The results of the subgroup analysis were consistent with those of the total mutation population (exon19: >18.5% vs. ≤18.5%, 14 months vs. 10 months, p = 0.049; exon21: >22.0% vs. ≤22.0%, 15 months vs. 9 months, p = 0.005). In addition, the mutation abundance of TP53 was negatively correlated with the DDA (p < 0.05). Patients in the combination group had a better DDA than those in the monotherapy group (p < 0.05). Subgroup analysis showed that, among the low mutation abundance of the EGFR exon 21 or 19 cohort, the combination group had a better DDA than the monotherapy group (p < 0.05). An EGFR mutation abundance greater than 22.0% was a positive predictor of DDA in patients with metastatic LUAD. However, a TP53 mutation abundance higher than 32.5% could reverse this situation. Finally, first-line treatment with EGFR-TKIs plus chemotherapy is a potential treatment strategy for patients with low-abundance EGFR mutations.

Mutant-allele dispersion correlates with prognosis risk in patients with advanced non-small cell lung cancer

BACKGROUND

Intra-tumor heterogeneity (ITH) contributes to lung cancer progression and resistance to therapy. To evaluate ITH and determine whether it may be employed as a predictive biomarker of prognosis in patients with advanced non-small cell lung cancer (NSCLC), we used a novel algorithm called mutant-allele dispersion (MAD).

METHODS

In the study, 103 patients with advanced NSCLC were enrolled. Using a panel of 425 cancer-related genes, next-generation sequencing (NGS) was performed on tumor specimens that had been collected. From NGS data, we derived MAD values, and we next looked into their relationships with clinical variables and different mutation subtypes.

RESULTS

The median MAD among 103 NSCLC patients was 0.73. EGFR mutation, tyrosine kinase inhibitor (TKI) therapy, radiotherapy, and chemotherapy cycles were all substantially correlated with the MAD score. In patients with lung adenocarcinoma (LUAD), correlation analysis revealed that the MAD score was substantially linked with Notch pathway mutation (P = 0.021). A significant relationship between high MAD and shorter progression-free survival (PFS) was found (HR = 2.004, 95%CI 1.269-3.163, P = 0.003). In patients with advanced NSCLC, histological type (P = 0.004), SMARCA4 mutation (P = 0.038), and LRP1B mutation (P = 0.006) were all independently associated with prognosis. The disease control rate was considerably greater in the low MAD group compared to the high MAD group in 19 LUAD patients receiving immunotherapy (92.9% vs. 40%, P = 0.037). TKI-PFS was longer in 37 patients with low MAD who received first-line TKI therapy (P = 0.014).

CONCLUSION

Our findings suggested that MAD is a practical and simple algorithm for assessing ITH, and populations with high MAD values are more likely to have EGFR mutations. MAD can be used as a potential biomarker to predict not only the prognosis of NSCLC but also the efficacy of immunotherapy and TKI therapy in patients with advanced NSCLC.

Racial and Ethnic Disparities in Survival Among People With Second Primary Cancer in the US

Importance

Comprehensive data for racial and ethnic disparities after second primary cancers (SPCs) are lacking despite the growing burden of SPCs.

Objective

To quantify racial and ethnic disparities in survival among persons with SPCs.

Design, Setting, and Participants

This population-based, retrospective cohort study used data from 18 Surveillance, Epidemiology, and End Results registries in the US for persons diagnosed with the most common SPCs at age 20 years or older from January 1, 2000, to December 31, 2013 (with follow-up through December 31, 2018). Data were analyzed between January and April 2023.

Exposure

Race and ethnicity (Hispanic, non-Hispanic Asian or Pacific Islander, non-Hispanic Black, and non-Hispanic White).

Main Outcomes and Measures

The main outcomes were 5-year relative survival and cause-specific survival. Cause-specific hazard ratios (HRs) were calculated for death from cancer or cardiovascular disease (CVD) in each racial and ethnic minority population compared with the White population overall and stratified by SPC type, with adjustment for sex, year and age at SPC diagnosis, and prior cancer type and stage (baseline model) and additionally for county attributes (household income, urbanicity), SPC characteristics (stage, subtype), and treatment.

Results

Among 230 370 persons with SPCs (58.4% male), 4.5% were Asian or Pacific Islander, 9.6% were Black, 6.4% were Hispanic, and 79.5% were White. A total of 109 757 cancer-related deaths (47.6%) and 18 283 CVD-related deaths (7.9%) occurred during a median follow-up of 54 months (IQR, 12-93 months). In baseline models, compared with the White population, the risk of cancer-related death overall was higher in the Black (HR, 1.21; 95% CI, 1.18-1.23) and Hispanic (HR, 1.10; 95% CI, 1.07-1.13) populations but lower in the Asian or Pacific Islander population (HR, 0.93; 95% CI, 0.90-0.96). When stratified by 13 SPC types, the risk of cancer-related death was higher for 10 SPCs in the Black population, with the highest HR for uterine cancer (HR, 1.87; 95% CI, 1.63-2.15), and for 7 SPCs in the Hispanic population, most notably for melanoma (HR, 1.46; 95% CI, 1.21-1.76). For CVD-related death, the overall HR was higher in the Black population (HR, 1.41; 95% CI, 1.34-1.49), with elevated risks evident for 11 SPCs, but lower in the Asian or Pacific Islander (HR, 0.75; 95% CI, 0.69-0.81) and Hispanic (HR, 0.90; 95% CI, 0.84-0.96) populations than in the White population. After further adjustments for county attributes and SPC characteristics and treatment, HRs were reduced for cancer-related death and for CVD-related death and associations in the same direction remained.

Conclusions and Relevance

In this cohort study of SPC survivors, the Black population had the highest risk of both death from cancer and death from CVD, and the Hispanic population had a higher risk of death from cancer than the White population. Attenuations in HRs after adjustment for potentially modifiable factors highlight opportunities to reduce survival disparities among persons with multiple primary cancers.

Adjuvant Treatments for Surgically Resected Non-Small Cell Lung Cancer Harboring EGFR Mutations: A Review

Importance

The use of adjuvant chemotherapy for stage IB-IIIA resected non-small cell lung cancer (NSCLC) has limited benefit for improving cure rates. The proportion of epidermal growth factor receptor (EGFR) alterations among patients with resected NSCLC is comparable to that observed in patients with advanced disease, and the use of EGFR tyrosine kinase inhibitors (TKIs) has been demonstrated to prolong disease-free survival (DFS). With recent approval of osimertinib in this context, a focus on the rapidly evolving scenario and future perspective in clinical practice is needed and was the aim of the current review.

Observations

Randomized phase 3 clinical trials demonstrated DFS benefit with adjuvant EGFR TKI therapy in patients with resected EGFR mutation-positive NSCLC. The most recent trial (ADAURA) assessed 3-year adjuvant osimertinib and showed consistent DFS benefit and a significant role of the intervention in preventing the occurrence of brain metastasis. However, the role of adjuvant chemotherapy, the appropriate duration of treatment, the management of disease relapse, and the effective cure rate remain undetermined. A deeper investigation on molecular biomarkers, covariant patterns, and dynamic monitoring of postsurgical circulating DNA would be helpful for the implementation of future strategies to further improve survival rates after adjuvant therapy for EGFR mutation-positive NSCLC.

Conclusions and Relevance

Adjuvant osimertinib revolutionized the treatment algorithm for patients with stage IB-IIIA resected EGFR mutation-positive NSCLC. Further evidence driven by clinical issues will be key for further optimization of the goals of adjuvant treatment in these patients.

Early immune pressure initiated by tissue-resident memory T cells sculpts tumor evolution in non-small cell lung cancer

Tissue-resident memory T (TRM) cells provide immune defense against local infection and can inhibit cancer progression. However, it is unclear to what extent chronic inflammation impacts TRM activation and whether TRM cells existing in tissues before tumor onset influence cancer evolution in humans. We performed deep profiling of healthy lungs and lung cancers in never-smokers (NSs) and ever-smokers (ESs), finding evidence of enhanced immunosurveillance by cells with a TRM-like phenotype in ES lungs. In preclinical models, tumor-specific or bystander TRM-like cells present prior to tumor onset boosted immune cell recruitment, causing tumor immune evasion through loss of MHC class I protein expression and resistance to immune checkpoint inhibitors. In humans, only tumors arising in ES patients underwent clonal immune evasion, unrelated to tobacco-associated mutagenic signatures or oncogenic drivers. These data demonstrate that enhanced TRM-like activity prior to tumor development shapes the evolution of tumor immunogenicity and can impact immunotherapy outcomes.

Prognostic value of cell-free DNA in cerebrospinal fluid from lung cancer patients with brain metastases during radiotherapy

BACKGROUND

During the last decades, radiotherapy (RT) for non-small cell lung cancer (NSCLC) with brain metastases (BM) has been developed. However, the lack of predictive biomarkers for therapeutic responses has limited the precision treatment in NSCLC-BM.

PATIENTS AND METHODS

In order to find the predictive biomarkers for RT, we investigated the influence of RT on the cell-free DNA (cfDNA) from cerebrospinal fluid (CSF) and the frequency of T cell subsets of NSCLC patients with BM. A total of 19 patients diagnosed as NSCLC with BM were enrolled. The CSF from 19 patients and matched plasma samples from 11 patients were collected before RT, during RT, and after RT. The cfDNA from CSF and plasma were extracted, and the cerebrospinal fluid tumor mutation burden (cTMB) was calculated after through next-generation sequencing. The frequency of T cell subsets in peripheral blood was using flow cytometry.

RESULTS

The detection rate of cfDNA was higher in CSF compared to plasma in the matched samples. The mutation abundance of cfDNA in CSF was decreased after RT. However, no significant difference was observed in cTMB before and after RT. Although the median intracranial progression-free survival (iPFS) has not yet been reached in patients with decreased or undetectable cTMB, there was a trend that these patients possessed longer iPFS compared to those with stable or increased cTMB (HR 0.28, 95% CI 0.07-1.18, P = 0.067). The proportion of CD4⁺T cells in peripheral blood was decreased after RT.

CONCLUSION

Our study indicates that cTMB can serve as a prognostic biomarker in NSCLC patients with BMs.

Unraveling the Impact of Intratumoral Heterogeneity on EGFR Tyrosine Kinase Inhibitor Resistance in EGFR-Mutated NSCLC

The advent of tyrosine kinase inhibitors (TKIs) for treating epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) has been a game changer in lung cancer therapy. However, patients often develop resistance to the drugs within a few years. Despite numerous studies that have explored resistance mechanisms, particularly in regards to collateral signal pathway activation, the underlying biology of resistance remains largely unknown. This review focuses on the resistance mechanisms of EGFR-mutated NSCLC from the standpoint of intratumoral heterogeneity, as the biological mechanisms behind resistance are diverse and largely unclear. There exist various subclonal tumor populations in an individual tumor. For lung cancer patients, drug-tolerant persister (DTP) cell populations may have a pivotal role in accelerating the evolution of tumor resistance to treatment through neutral selection. Cancer cells undergo various changes to adapt to the new tumor microenvironment caused by drug exposure. DTP cells may play a crucial role in this adaptation and may be fundamental in mechanisms of resistance. Intratumoral heterogeneity may also be precipitated by DNA gains and losses through chromosomal instability, and the role of extrachromosomal DNA (ecDNA) may play an important role. Significantly, ecDNA can increase oncogene copy number alterations and enhance intratumoral heterogeneity more effectively than chromosomal instability. Additionally, advances in comprehensive genomic profiling have given us insights into various mutations and concurrent genetic alterations other than EGFR mutations, inducing primary resistance in the context of tumor heterogeneity. Understanding the mechanisms of resistance is clinically crucial since these molecular interlayers in cancer-resistance mechanisms may help to devise novel and individualized anticancer therapeutic approaches.

Why loss of Y? A pan-cancer genome analysis of tumors with loss of Y chromosome

Loss of the Y chromosome (LoY) is frequently observed in somatic cells of elderly men. However, LoY is highly increased in tumor tissue and correlates with an overall worse prognosis. The underlying causes and downstream effects of LoY are widely unknown. Therefore, we analyzed genomic and transcriptomic data of 13 cancer types (2375 patients) and classified tumors of male patients according to loss or retain of the Y chromosome (LoY or RoY, average LoY fraction: 0.46). The frequencies of LoY ranged from almost absence (glioblastoma, glioma, thyroid carcinoma) to 77% (kidney renal papillary cell carcinoma). Genomic instability, aneuploidy, and mutation burden were enriched in LoY tumors. In addition, we found more frequently in LoY tumors the gate keeping tumor suppressor gene TP53 mutated in three cancer types (colon adenocarcinoma, head and neck squamous carcinoma, lung adenocarcinoma) and oncogenes MET, CDK6, KRAS, and EGFR amplified in multiple cancer types. On the transcriptomic level, we observed MMP13, known to be involved in invasion, to be up-regulated in LoY of three adenocarcinomas and down-regulation of the tumor suppressor gene GPC5 in LoY of three cancer types. Furthermore, we found enrichment of a smoking-related mutation signature in LoY tumors of head and neck and lung cancer. Strikingly, we observed a correlation between cancer type-specific sex bias in incidence rates and frequencies of LoY, in line with the hypothesis that LoY increases cancer risk in males. Overall, LoY is a frequent phenomenon in cancer that is enriched in genomically unstable tumors. It correlates with genomic features beyond the Y chromosome and might contribute to higher incidence rates in males.

WMDS.net: a network control framework for identifying key players in transcriptome programs

MOTIVATION

Mammalian cells can be transcriptionally reprogramed to other cellular phenotypes. Controllability of such complex transitions in transcriptional networks underlying cellular phenotypes is an inherent biological characteristic. This network controllability can be interpreted by operating a few key regulators to guide the transcriptional program from one state to another. Finding the key regulators in the transcriptional program can provide key insights into the network state transition underlying cellular phenotypes.

RESULTS

To address this challenge, here, we proposed to identify the key regulators in the transcriptional co-expression network as a minimum dominating set (MDS) of driver nodes that can fully control the network state transition. Based on the theory of structural controllability, we developed a weighted MDS network model (WMDS.net) to find the driver nodes of differential gene co-expression networks. The weight of WMDS.net integrates the degree of nodes in the network and the significance of gene co-expression difference between two physiological states into the measurement of node controllability of the transcriptional network. To confirm its validity, we applied WMDS.net to the discovery of cancer driver genes in RNA-seq datasets from The Cancer Genome Atlas. WMDS.net is powerful among various cancer datasets and outperformed the other top-tier tools with a better balance between precision and recall.

AVAILABILITY AND IMPLEMENTATION

https://github.com/chaofen123/WMDS.net.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Integrated analysis reveals common DNA methylation patterns of alcohol-associated cancers: A pan-cancer analysis

Background: The role of alcohol in carcinogenesis has received increasing attention in recent years. Evidence shows its impacts on various aspects, including epigenetics alteration. The DNA methylation patterns underlying alcohol-associated cancers are not fully understood. Methods: We investigated the aberrant DNA methylation patterns in four alcohol-associated cancers based on the Illumina HumanMethylation450 BeadChip. Pearson coefficient correlations were identified between differential methylated CpG probes and annotated genes. Transcriptional factor motifs were enriched and clustered using MEME Suite, and a regulatory network was constructed. Results: In each cancer, differential methylated probes (DMPs) were identified, and 172 hypermethylated and 21 hypomethylated pan-cancer DMPs (PDMPs) were examined further. Annotated genes significantly regulated by PDMPs were investigated and enriched in transcriptional misregulation in cancers. The CpG island chr19:58220189-58220517 was hypermethylated in all four cancers and silenced in the transcription factor ZNF154. Various biological effects were exerted by 33 hypermethylated and seven hypomethylated transcriptional factor motifs grouped into five clusters. Eleven pan-cancer DMPs were identified to be associated with clinical outcomes in the four alcohol-associated cancers, which might provide a potential point of view for clinical outcome prediction. Conclusion: This study provides an integrated insight into DNA methylation patterns in alcohol-associated cancers and reveals the corresponding features, influences, and potential mechanisms.

Genomic features and its potential implication in bone oligometastatic NSCLC

OBJECTIVES

Emerging evidence have demonstrated that oligometastatic non-small cell lung cancer (NSCLC) can achieve clinical benefit from local consolidative therapy. Bone oligometastasis is common in advanced lung cancer, but little is known about its molecular features. The purpose of our study aimed to investigate the genomic landscape bone oligometastatic NSCLC.

METHODS

We collected paired blood and tissue samples from 31 bone oligometastatic NSCLC patients to make a comprehensive analysis of mutations by performing next-generation sequencing.

RESULTS

A total of 186 genomic mutations were detected from 105 distinct cancer-relevant genes, with a median number of 6 alterations per tumor. The most frequently mutated genes were EGFR (58%) and TP53 (55%), followed by KRAS (16%), CDKN2A (13%) and MET (13%). The signatures related to smoking, aging, homologous recombination deficiency and APOBEC were identified as the most important mutational processes in bone oligometastasis. The median tumor mutation burden was 4.4 mutations/Mb. Altogether, genetic alterations of bone oligometastasis are highly targetable that 74.19% of patients had at least one actionable alteration that was recommended for targeted therapy based on the OncoKB evidence. Of these patients, 16.13% had two actionable alterations that could potentially benefit from a different combination of targeted drugs to achieve better outcomes.

CONCLUSION

Our research comprehensively elucidates the genomic features of bone oligometastatic NSCLC patients, which may optimize individualized cancer treatment in the era of precision medicine.

Frequently mutated genes in predicting the relapse of stage I lung adenocarcinoma

PURPOSE

Approximately, 45-65% stage I non-small cell lung cancer (NSCLC) patients with surgical resection relapse within 5 years. Therefore, it is urgent to identify the predictors involved in the relapse of stage I NSCLC.

METHODS/PATIENTS

Targeted sequencing was used to examine the mutation of tumor tissues and matched adjacent normal tissues from 35 patients with stage I lung adenocarcinoma (LUAD). Then, tissue microarrays containing tumor tissues from 149 stage I LUAD patients were used to assess protein expression of frequently mutated genes by immunohistochemistry. COX regression model was used to evaluate the impacts of frequently mutated genes and their protein expression on relapse-free survival (RFS) in stage I LUAD.

RESULTS AND CONCLUSIONS

Three hundred and twenty-nine non-synonymous somatic variants were identified in 161 genes among these 35 patients. EGFR, TP53, LRP1B, RBM10, KRAS, NTRK3, RB1, ALK, APC, FAT2, KEAP1, MED12 and MLL3 were described as frequently mutated genes with prevalence more than 10%. Patients harboring KRAS mutation had more relapse in 1 year after surgical resection. For the expression of these frequently mutated genes in 149 stage I patients, multivariate Cox regression analyses showed that the expression of RBM10 was positively associated with RFS in all patients (HR 0.40, 95% CI 0.15-1.0, p = 0.052), and the expression of APC was negative associated with RFS in patients with EGFR mutations (HR 3.10, 95% CI 1.54-6.26, p = 0.002). Stage I LUAD patients with KRAS mutation or low RBM10 expression are inclined to receive more positive intervention rather than just disease surveillance.

Anlotinib combined with osimertinib reverses acquired osimertinib resistance in NSCLC by targeting the c-MET/MYC/AXL axis

Favorable clinical evidence suggests that the next trend in new treatments for advanced non-small cell lung cancer (NSCLC) will be combination therapies. However, inevitable epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) resistance greatly limits the clinical efficacy of patients carrying EGFR-activating mutants. In this study, we found a patient with clinical osimertinib resistance who regained a positive response after osimertinib plus anlotinib treatment. Two osimertinib-resistant cell lines were constructed, and AXL conferred resistance to osimertinib in NSCLC cell lines. The combined effects of anlotinib and osimertinib restored sensitivity to osimertinib in two osimertinib-resistant NSCLC cell lines and in xenografts. Moreover, anlotinib inhibits the phosphorylation of AXL in both resistant cell lines. Mechanistically, we confirmed that MYC binds to the promoter of AXL to promote its transcription in NSCLC cells, and we demonstrated that anlotinib combined with osimertinib treatment enhances the anti-tumor effect by inactivating the c-MET/MYC/AXL axis to reverse osimertinib resistance in NSCLC. In conclusion, our results provide strong support that this combination therapy may be effective in enhancing the efficacy of treatments in patients with advanced NSCLC.

Predictive value of p53 and AXL immunostaining for the efficacy of immune checkpoint inhibitor-based therapy after osimertinib treatment in patients with epidermal growth factor-mutant non-small cell lung cancer

BACKGROUND

Current evidence indicates that immune checkpoint inhibitors (ICIs) have a limited efficacy in patients with lung cancer harboring epidermal growth factor receptor (EGFR) mutations. However, there is a lack of data on the efficacy of ICIs after osimertinib treatment, and the predictors of ICI efficacy are unclear.

METHODS

We retrospectively assessed consecutive patients with EGFR-mutant NSCLC who received ICI-based therapy after osimertinib treatment at 10 institutions in Japan, between March 2016 and March 2021. Immunohistochemical staining was used to evaluate the expression of p53 and AXL. The deletions of exon 19 and the exon 21 L858R point mutation in EGFR were defined as common mutations; other mutations were defined as uncommon mutations.

RESULTS

A total of 36 patients with advanced or recurrent EGFR-mutant NSCLC were analyzed. In multivariate analysis, p53 expression in tumors was an independent predictor of PFS after ICI-based therapy (p = 0.002). In patients with common EGFR mutations, high AXL expression was a predictor of shorter PFS and overall survival after ICI-based therapy (log-rank test; p = 0.04 and p = 0.02, respectively).

CONCLUSION

The levels of p53 in pretreatment tumors may be a predictor of ICI-based therapy outcomes in patients with EGFR-mutant NSCLC after osimertinib treatment. High levels of AXL in tumors may also be a predictor of ICI-based therapy outcomes, specifically for patients with common EGFR mutations. Further prospective large-scale investigations on the predictors of ICI efficacy following osimertinib treatment are warranted.

PD-L1 score as a prognostic biomarker in asian early-stage epidermal growth factor receptor-mutated lung cancer

AIM

To determine the prognostic value of programmed death-ligand 1 (PD-L1) score in early-stage epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC), contrasted against EGFR-wildtype NSCLC.

METHODS

Consecutive patients with Stage IA-IIIA NSCLC diagnosed 1st January 2010-31st December 2019 at National Cancer Centre Singapore with evaluable EGFR and PD-L1 status were included. Co-primary end-points were 2-year disease-free survival (DFS) and 5-year overall survival (OS) by Kaplan-Meier method.

RESULTS

455 patients were included (267 EGFR-mutated, EGFR-M+; 188 EGFR-wildtype, wt). Median age at diagnosis was 65 years, 52.3% (238/455) of patients were males, 62.9% (286/455) of patients were never-smokers and 92.5% (421/455) of patients had R0 resection. Stage IA comprised 42.4% (193/455) of patients, Stage IB comprised 23.1% (105/455) of patients, Stage IIA comprised 10.8% of patients (49/455), Stage IIB comprised 5.1% of patients (23/455) and Stage IIIA comprised 18.7% (85/455) of patients. Among EGFR-M+, 45.3% (121/267) were Ex19del and 41.9% (112/267) were L858R. PD-L1 ≥1% among EGFR-M+ and EGFR-wt was 45.3% (121/267) and 54.8% (103/188) respectively (p = 0.047). At median follow-up of 47 months, 178 patients had relapsed. Among EGFR-M+, 2-year DFS comparing PD-L1 <1% and PD-L1 ≥1% was 78.1% and 67.6% (p = 0.007) while 5-year OS was 59.5% and 42.8% (p = 0.001), respectively. Controlling for age, gender, lymphovascular invasion, adjuvant therapy and resection margin status, PD-L1 ≥1% (hazard ratio, HR 2.18, 95% CI 1.04-4.54, p = 0.038), stage IIB (HR 7.78, 95% CI 1.72-35.27, p = 0.008) and stage IIIA (HR 4.45, 95% CI 1.44-13.80, p = 0.01) emerged as independent predictors of inferior OS on multivariable analysis. In exploratory analysis, genomic analysis of 81 EGFR-M+ tumours was performed. PD-L1 ≥1% tumours had significantly higher rates of TP53 mutations (36.1% versus 15.6%, p = 0.04), with predominantly missense mutations.

CONCLUSION

PD-L1 ≥1% is an independent predictor of worse OS among early-stage EGFR-mutated NSCLC and is associated with inferior DFS regardless of EGFR status. PD-L1 score as a risk stratification factor should be evaluated in prospective adjuvant studies among EGFR-mutated NSCLC.

The surgical resection of the primary tumor increases survival in patients with EGFR-mutant advanced non-small cell lung cancer: a tertiary center cohort study

Tumor resection could increase treatment efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKI) in patients with advanced EGFR-mutant non-small cell lung cancer (NSCLC). This study aimed to retrospectively analyze patients with advanced EGFR-mutant NSCLC from a Taiwanese tertiary center and receiving EGFR-TKI treatment with or without tumor resection. A total of 349 patients were enrolled. After propensity score matching, 53 EGFR-TKI treated patients and 53 EGFR-TKI treated patients with tumor resection were analyzed. The tumor resection group showed improved progression-free survival (PFS) (52.0 vs. 9.8 months; hazard ratio [HR] = 0.19; p < 0.001) and overall survival (OS) (not reached vs. 30.6 months; HR = 0.14; p < 0.001) compared to the monotherapy group. In the subgroup analysis of patients with newly-diagnosed NSCLC, the tumor resection group showed longer PFS (52.0 vs. 9.9 months; HR = 0.14; p < 0.001) and OS (not reached vs. 32.6 months; HR = 0.12; p < 0.001) than the monotherapy group. In conclusion. the combination of EGFR-TKI and tumor resection provided better PFS and OS than EGFR-TKI alone, and patients who underwent tumor resection within six months had fewer co-existing genomic alterations and better PFS.

Characterization of driver mutations in Chinese non-small cell lung cancer patients using a novel targeted sequencing panel

Background

The identification of driver mutations has greatly promoted the precise diagnosis and treatment of non-small cell lung cancer (NSCLC), but there is lack of targeted sequencing panels specifically designed and applied to Chinese NSCLC patients. This study aimed to design and validate of a novel sequencing panel for comprehensive characterization of driver mutations in Chinese NSCLC patients, facilitating further exploration of downstream pathway alterations and therapeutic utility.

Methods

A novel target sequencing panel including 21 driver genes was designed and examined in a cohort of 260 Chinese NSCLC patients who underwent surgery in Peking Union Medical College Hospital (PUMCH). Genetic alterations were identified and further analyzed for driver mutations, downstream pathways and therapeutic utilities.

Results

The most frequently identified driver mutations in PUMCH NSCLC cohort were on genes TP53 (28%), EGFR (27%) and PIK3CA (19%) for lung adenocarcinoma (LUAD), and TP53 (41%), PIK3CA (14%) and CDKN2A (13%) for lung squamous cell carcinoma (LUSC), respectively. Downstream pathway analysis revealed common pathways like G1_AND_S1_PHASES pathway were shared not only between LUAD and LUSC patients, but also among three different NSCLC cohorts, while other pathways were subtype-specific, like the unique enrichment of SHC1_EVENT_IN_EGFR_SIGNALING pathway in LUAD patients, and P38_ALPHA_BETA_DOWNSTREAM pathway in LUSC patients, respectively. About 60% of both LUAD and LUSC patients harbored driver mutations as sensitive biomarkers for different targeted therapies, covering not only frequent mutations like EGFR L858R mutation, but also rare mutations like BRAF D594N mutation.

Conclusions

Our study provides a novel target sequencing panel suitable for Chinese NSCLC patients, which can effectively identify driver mutations, analyze downstream pathway alterations and predict therapeutic utility. Overall it is promising to further optimize and apply this panel in clinic with convenience and effectiveness.

Utility of cell-free DNA from bronchial washing fluid in diagnosis and genomic determination for radiology-suspected pulmonary nodules

BACKGROUND

Bronchial washing fluid (BWF) is a less-invasive specimen. Due to the limited sensitivity of BWF cellular component diagnosis, the aim of this study was to explore the potential role of BWF supernatant as a source of liquid biopsy of lung cancer.

METHODS

This prospective study enrolled 76 suspected and 5 progressed lung cancer patients. Transbronchial biopsy tissues, BWF supernatant (BWF_Sup) and BWF precipitant (BWF_Pre) were tested by a targeted panel of 1021 genes.

RESULTS

BWF_Sup cell-free DNA (cfDNA) was superior to tissue biopsy and BWF_Pre in determining mutational allele frequency, tumour mutational burden, and chromosomal instability. Moreover, BWF_Sup and BWF_Pre achieved comparable efficacy to tissue samples in differentiating malignant and benign patients, but only BWF_Sup persisted differentiated performance after excluding 55 malignancies pathologically diagnosed by bronchoscopic biopsy. Among 67 malignant patients, 82.1% and 71.6% of tumour-derived mutations (TDMs) were detected in BWF_Sup and BWF_Pre, respectively, and the detectability of TDMs in BWF_Sup was independent of the cytological examination of BWF. BWF_Sup outperformed BWF_Pre in providing more subclonal information and thus might yield advantage in tracking drug-resistant markers.

CONCLUSIONS

BWF_Sup cfDNA is a reliable medium for lung cancer diagnosis and genomic profiles and may provide important information for subsequent therapeutic regimens.

Comprehensive genomic analysis of primary malignant melanoma of the esophagus reveals similar genetic patterns compared with epithelium-associated melanomas

Primary malignant melanoma of the esophagus (PMME) is an exceedingly rare disease with a poor prognosis. The etiology of PMME remains largely unknown and genetic characteristics are yet to be clarified, essential for identifying potential therapeutic targets and defining treatment guidelines. Here, we performed whole-exome sequencing on 47 formalin-fixed paraffin-embedded specimens from 18 patients with PMME, including 23 tumor samples, 6 metastatic lymph nodes, and 18 tumor-adjacent normal tissues. The genomic features of PMME were comprehensively characterized, and comparative genomic analysis was further performed between these specimens and 398 skin cutaneous melanomas (SKCM), 67 non-esophagus mucosal melanomas (NEMM), and 79 uveal melanomas (UVM). In the PMME cohort, recurrently mutated driver genes, such as MUC16, RANBP2, NRAS, TP53, PTPRT, NF1, MUC4, KMT2C, and BRAF, were identified. All RANBP2 mutations were putatively deleterious, and most affected samples had multipoint mutations. Furthermore, RANBP2 showed parallel evolution by multiregional analysis. Whole-genome doubling was an early truncal event that occurred before most driver mutations, except for in TP53. An ultraviolet radiation-related mutational signature, SBS38, was identified as specific to epithelial melanomas and could predict inferior survival outcomes in both PMME and SKCM patients. Comparing the mutational and copy number landscapes between PMME and other subtypes of melanoma revealed that PMME has a similar genomic pattern and biological characteristics to SKCM. In summary, we comprehensively defined the key genomic aberrations and mutational processes driving PMME and suggested for the first time that PMME may share similar genomic patterns with SKCM; therefore, patients with rare melanomas, such as PMME, may benefit from the current treatment used for common cutaneous melanoma.

MET alterations in NSCLC—Current Perspectives and Future Challenges

Targeted therapies have revolutionized the treatment and improved the outcome for oncogene-driven NSCLC and an increasing number of oncogenic driver therapies have become available. For MET-dysregulated NSCLC (especially MET exon 14 skipping mutations and MET-amplifications, which is one of the most common bypass mechanisms of resistance in oncogene-addicted NSCLC), several anti-MET-targeted therapies have been approved recently (MET exon 14 skipping mutation) and multiple others are in development. In this narrative review, we summarize the role of MET as an oncogenic driver in NSCLC, discuss the different testing methods for exon 14 skipping mutations, gene amplification, and protein overexpression, and review the existing data and ongoing clinical trials regarding targeted therapies in MET-altered NSCLC. As immunotherapy with or without chemotherapy has become the standard of care for advanced NSCLC, immunotherapy data for MET-dysregulated NSCLC are put into perspective. Finally, we discuss future challenges in this rapidly evolving landscape.

Overview of the multifaceted resistances toward EGFR-TKIs and new chemotherapeutic strategies in non-small cell lung cancer

The role of epidermal growth factor receptor (EGFR) in non-small cell lung cancer (NSCLC) has been vastly studied over the last decade. This has led to the rapid development of many generations of EGFR tyrosine kinase inhibitors (EGFR-TKIs). However, patients treated with third-generation TKIs (osimertinib, avitinib and rociletinib) targeting the EGFR T790M mutation have shown emerging resistances and relapses. Therefore, further molecular understanding of NSCLC mutations, bypass signalling, tumour microenvironment and the existence of cancer stem cells to overcome such resistances is warranted. This will pave the way for designing novel and effective chemotherapies to improve patients' overall survival. In this review, we provide an overview of the multifaceted mechanism of resistances towards EGFR-TKIs, as well as the challenges and perspectives that should be addressed in strategising chemotherapeutic treatments to overcome the ever evolving and adaptive nature of NSCLC.

Clonal evolution characteristics and reduced dimension prognostic model for non-metastatic metachronous bilateral breast cancer

BACKGROUND

How to evaluate the prognosis and develop overall treatment strategies of metachronous bilateral breast cancer (MBBC) remains confused in clinical. Here, we investigated the correlation between clonal evolution and clinical characteristics of MBBC; we aim to establish a novel prognostic model in these patients.

METHODS

The data from Surveillance, Epidemiology, and End Results (SEER) database and the First Hospital of Jilin University were analyzed for breast cancer-specific cumulative mortality (BCCM) by competing risk model. Meanwhile, whole-exome sequencing was applied for 10 lesions acquired at spatial-temporal distinct regions of five patients from our own hospital to reconstruct clonal evolutionary characteristics of MBBC. Then, dimensional-reduction (DR) cumulative incidence function (CIF) curves of MBBC features were established on different point in diagnostic interval time, to build a novel DR nomogram.

RESULTS

Significant heterogeneity in genome and clinical features of MBBC was widespread. The mutational diversity of contralateral BC (CBC) was significantly higher than that in primary BC (PBC), and the most effective prognostic MATH ratio was significantly correlated with interval time (R 2 = 0.85, p< 0.05). In SEER cohort study (n = 13,304), the interval time was not only significantly affected the BCCM by multivariate analysis (p< 0.000) but determined the weight of clinical features (T/N stage, grade and ER status) on PBC and CBC in prognostic evaluation. Thus, clinical parameters after DR based on interval time were incorporated into the nomogram for prognostic predicting BCCM. Concordance index was 0.773 (95% CI, 0.769-0.776) in training cohort (n = 8,869), and 0.819 (95% CI, 0.813-0.826) in validation cohort (n = 4,435).

CONCLUSIONS

Bilateral heterogeneous characteristics and interval time were determinant prognostic factors of MBBC. The DR prognostic nomogram may help clinicians in prognostic evaluation and decision making.

The comparison of cancer gene mutation frequencies in Chinese and U.S. patient populations

Knowing the mutation frequency of cancer genes in China is crucial for reducing the global health burden. We integrate the tumor epidemiological statistics with cancer gene mutation rates identified in 11,948 cancer patients to determine their weighted proportions within a Chinese cancer patient cohort. TP53 (51.4%), LRP1B (13.4%), PIK3CA (11.6%), KRAS (11.1%), EGFR (10.6%), and APC (10.5%) are identified as the top mutated cancer genes in China. Additionally, 18 common cancer types from both China and U.S. cohorts are analyzed and classified into three patterns principally based upon TP53 mutation rates: TP53-Top, TP53-Plus, and Non-TP53. Next, corresponding similarities and prominent differences are identified upon comparing the mutational profiles from both cohorts. Finally, the potential population-specific and environmental risk factors underlying the disparities in cancer gene mutation rates between the U.S. and China are analyzed. Here, we show and compare the mutation rates of cancer genes in Chinese and U.S. population cohorts, for a better understanding of the associated etiological and epidemiological factors, which are important for cancer prevention and therapy.

Molecular Divergence upon EGFR-TKI Resistance Could Be Dependent on the Exon Location of the Original EGFR-Sensitizing Mutation

Tumor molecular profiling upon disease progression enables investigations of the tumor evolution. Next-generation sequencing (NGS) of liquid biopsies constitutes a noninvasive readily available source of tumor molecular information. In this study, 124 plasma samples from advanced EGFR-positive NSCLC patients, treated with a first-line EGFR tyrosine kinase inhibitor (EGFR-TKI) were collected upon disease progression. The circulating cell-free DNA (cfDNA) was sequenced using the Oncomine Pan-Cancer Cell-Free Assay™. Excluding EGFR mutations, the most frequently mutated gene was TP53 (57.3%), followed by APC (11.3%), FGFR3 (7.3%), and KRAS (5.6%). Different molecular alterations were observed upon disease progression depending on the location of the original EGFR-sensitizing mutation. Specifically, the detection of the p.T790M mutation was significantly associated with the presence of exon 19 mutations in EGFR (Fisher p-value: 0.028). All KRAS activating mutations (n = 8) were detected in tumors with EGFR mutations in exons 18 and 21 (Fisher p-value < 0.001). Similarly, mutations in NRAS and HRAS were more frequently detected in samples from tumors harboring mutations in exons 18 or 21 (Fisher p-value: 0.050 and Fisher p-value: 0.099, respectively). In conclusion, our data suggest that the mechanisms underlying EGFR-TKI resistance could be dependent on the exon location of the original EGFR-sensitizing mutation.

Targeted Therapy in Early Stage Non-small Cell Lung Cancer

OPINION STATEMENT

Tyrosine kinase inhibitors (TKIs) have dramatically improved tumor response rates and survival benefits in advanced oncogenic non-small-cell lung cancer (NSCLC). Given the impressive success, a renewed interest has been raised in the study of these agents in the perioperative setting. Preliminary data have shown dramatic effectiveness compared to conventional chemotherapy. Given the explicit need to induce durable responses and raise cure rates, we summarize the current progression, identify key challenges, and raise potential opportunities for perioperative targeted therapy that range from precise biomarkers to optimal adjuvant regimens for individual patients. As perioperative treatment indeed provides researchers with a unique platform to address the challenges mentioned above, investigators could obtain a comprehensive analysis of genomic profiling and trace resistance mechanisms. Multidisciplinary collaboration and adaptive clinical trial designs are warranted to integrate translational research into personalized perioperative TKI treatment paradigms.

Mutant-Allele Tumor Heterogeneity, a Favorable Biomarker to Assess Intra-Tumor Heterogeneity, in Advanced Lung Adenocarcinoma

Background

Intra-tumor heterogeneity (ITH) plays a vital role in drug resistance and recurrence of lung cancer. We used a mutant-allele tumor heterogeneity (MATH) algorithm to assess ITH and investigated its association with clinical and molecular features in advanced lung adenocarcinoma.

Methods

Tissues from 63 patients with advanced lung adenocarcinoma were analyzed by next-generation sequencing (NGS) using a panel targeting 520 cancer-relevant genes. We calculated the MATH values from NGS data and further investigated their correlation with clinical and molecular characteristics.

Results

Among the 63 patients with advanced lung adenocarcinoma, the median value of MATH was 33.06. Patients with EGFR mutation had higher level of MATH score than those with wild-type EGFR status (P = 0.008). Patients with stage IV disease showed a trend to have a higher MATH score than those with stage III (P = 0.052). MATH was higher in patients with disruptive TP53 mutations than in those with non-disruptive mutations (P = 0.036) or wild-type sequence (P = 0.023), but did not differ between tumors with non-disruptive mutations and wild-type TP53 (P = 0.867). High MATH is associated with mutations in mismatch repair (MMR) pathway (P = 0.026) and base excision repair (BER) pathway (P = 0.008). In addition, MATH was found to have a positive correlation with tumor mutational burden (TMB) (Spearman ρ = 0.354; P = 0.004). In 26 patients harboring EGFR mutation treated with first generation EGFR TKI as single-agent therapy, the objective response rate was higher in the Low-MATH group than in the High-MATH group (75% vs. 21%; P = 0.016) and Low-MATH group showed a significantly longer progression-free survival than High-MATH group (median PFS: 13.7 months vs. 10.1 months; P = 0.024).

Conclusions

For patients with advanced lung adenocarcinoma, MATH may serve as a clinically practical biomarker to assess intratumor heterogeneity.

A phylogenetic approach to study the evolution of somatic mutational processes in cancer

Cancer cell genomes change continuously due to mutations, and mutational processes change over time in patients, leaving dynamic signatures in the accumulated genomic variation in tumors. Many computational methods detect the relative activities of known mutation signatures. However, these methods may produce erroneous signatures when applied to individual branches in cancer cell phylogenies. Here, we show that the inference of branch-specific mutational signatures can be improved through a joint analysis of the collections of mutations mapped on proximal branches of the cancer cell phylogeny. This approach reduces the false-positive discovery rate of branch-specific signatures and can sometimes detect faint signatures. An analysis of empirical data from 61 lung cancer patients supports trends based on computer-simulated datasets for which the correct signatures are known. In lung cancer somatic variation, we detect a decreasing trend of smoking-related mutational processes over time and an increasing influence of APOBEC mutational processes as the tumor evolution progresses. These analyses also reveal patterns of conservation and divergence of mutational processes in cell lineages within patients.

Phasing analysis of lung cancer genomes using a long read sequencer

Chromosomal backgrounds of cancerous mutations still remain elusive. Here, we conduct the phasing analysis of non-small cell lung cancer specimens of 20 Japanese patients. By the combinatory use of short and long read sequencing data, we obtain long phased blocks of 834 kb in N50 length with >99% concordance rate. By analyzing the obtained phasing information, we reveal that several cancer genomes harbor regions in which mutations are unevenly distributed to either of two haplotypes. Large-scale chromosomal rearrangement events, which resemble chromothripsis events but have smaller scales, occur on only one chromosome, and these events account for the observed biased distributions. Interestingly, the events are characteristic of EGFR mutation-positive lung adenocarcinomas. Further integration of long read epigenomic and transcriptomic data reveal that haploid chromosomes are not always at equivalent transcriptomic/epigenomic conditions. Distinct chromosomal backgrounds are responsible for later cancerous aberrations in a haplotype-specific manner.

Whole-exome sequencing analysis of NSCLC reveals the pathogenic missense variants from cancer-associated genes

BACKGROUND

Non-small-cell lung cancer (NSCLC) is the most common type of lung cancer. NSCLC accounts for 84% of all lung cancer cases. In recent years, advances in pathway understanding, methods for discovering novel genetic biomarkers, and new drugs designed to inhibit the signaling cascades have enabled clinicians to personalize therapy for NSCLC.

OBJECTIVES

The primary aim of this study is to identify the genes associated with NSCLC that harbor pathogenic variants that could be causative for NSCLC. The second aim is to investigate their roles in different pathways that lead to NSCLC.

METHODS

We examined exome-sequencing datasets from 54 NSCLC patients to characterize the variants associated with NSCLC.

RESULTS

Our findings revealed that 17 variants in 14 genes were considered highly pathogenic, including CDKN2A, ERBB2, FOXP1, IDH1, JAK3, KMT2D, K-Ras, MSH3, MSH6, POLE, RNF43, TCF7L2, TP53, and TSC1. Gene set enrichment analysis revealed the involvement of transmembrane receptor protein tyrosine kinase activity, protein binding, ATP binding, phosphatidylinositol-4,5-bisphosphate 3-kinase, and Ras guanyl-nucleotide exchange factor activity. Pathway analysis of these genes yielded different cancer-related pathways, including colorectal, prostate, endometrial, pancreatic, PI3K-Akt signaling pathways, and signaling pathways regulating pluripotency of stem cells. Module 1 from protein-protein interactions (PPIs) identified genes that harbor pathogenic SNPs. Three of the most deleterious SNPs are ERBB2 (rs1196929947), K-Ras (rs121913529), and POLE (rs751425952). Interestingly, one patient has a pathogenic K-Ras variant (rs121913529) co-occurred with the missense variant (rs752054698) inTSC1 gene.

CONCLUSION

This study maps highly pathogenic variants associated with NSCLC and investigates their contributions to the pathogenesis of NSCLC. This study sheds light on the potential applications of precision medicine in patients with NSCLC.

Concurrent TP53 Mutations Facilitate Resistance Evolution in EGFR-Mutant Lung Adenocarcinoma

INTRODUCTION

Patients with EGFR-mutant NSCLC experience variable duration of benefit on EGFR tyrosine kinase inhibitors. The effect of concurrent genomic alterations on outcome has been incompletely described.

METHODS

In this retrospective study, targeted next-generation sequencing data were collected from patients with EGFR-mutant lung cancer treated at the Dana-Farber Cancer Institute. Clinical data were collected and correlated with somatic mutation data. Associations between TP53 mutation status, genomic features, and mutational processes were analyzed.

RESULTS

A total of 269 patients were identified for inclusion in the cohort. Among 185 response-assessable patients with pretreatment specimens, TP53 alterations were the most common event associated with decreased first-line progression-free survival and decreased overall survival, along with DNMT3A, KEAP1, and ASXL1 alterations. Reduced progression-free survival on later-line osimertinib in 33 patients was associated with MET, APC, and ERBB4 alterations. Further investigation of the effect of TP53 alterations revealed an association with worse outcomes even in patients with good initial radiographic response, and faster acquisition of T790M and other resistance mechanisms. TP53-mutated tumors had higher mutational burdens and increased mutagenesis with exposure to therapy and tobacco. Cell cycle alterations were not independently predictive, but portended worse OS in conjunction with TP53 alterations.

CONCLUSIONS

TP53 alterations associate with faster resistance evolution independent of mechanism in EGFR-mutant NSCLC and may cooperate with other genomic events to mediate acquisition of resistance mutations to EGFR tyrosine kinase inhibitors.

Deficiency of the splicing factor RBM10 limits EGFR inhibitor response in EGFR mutant lung cancer

Molecularly targeted cancer therapy has improved outcomes for patients with cancer with targetable oncoproteins, such as mutant EGFR in lung cancer. Yet, the long-term survival of these patients remains limited, because treatment responses are typically incomplete. One potential explanation for the lack of complete and durable responses is that oncogene-driven cancers with activating mutations of EGFR often harbor additional co-occurring genetic alterations. This hypothesis remains untested for most genetic alterations that co-occur with mutant EGFR. Here, we report the functional impact of inactivating genetic alterations of the mRNA splicing factor RNA-binding motif 10 (RBM10) that co-occur with mutant EGFR. RBM10 deficiency decreased EGFR inhibitor efficacy in patient-derived EGFR-mutant tumor models. RBM10 modulated mRNA alternative splicing of the mitochondrial apoptotic regulator Bcl-x to regulate tumor cell apoptosis during treatment. Genetic inactivation of RBM10 diminished EGFR inhibitor–mediated apoptosis by decreasing the ratio of (proapoptotic) Bcl-xS to (antiapoptotic) Bcl-xL isoforms of Bcl-x. RBM10 deficiency was a biomarker of poor response to EGFR inhibitor treatment in clinical samples. Coinhibition of Bcl-xL and mutant EGFR overcame the resistance induced by RBM10 deficiency. This study sheds light on the role of co-occurring genetic alterations and on the effect of splicing factor deficiency on the modulation of sensitivity to targeted kinase inhibitor cancer therapy.