The Comprehensive Analyses of Genomic Variations and Assessment of TMB and PD-L1 Expression in Chinese Lung Adenosquamous Carcinoma

EML4-ALK fusions drive lung adeno-to-squamous transition through JAK-STAT activation

Human lung adenosquamous cell carcinoma (LUAS), containing both adenomatous and squamous pathologies, exhibits strong cancer plasticity. We find that ALK rearrangement is detectable in 5.1-7.5% of human LUAS, and transgenic expression of EML4-ALK drives lung adenocarcinoma (LUAD) formation initially and squamous transition at late stage. We identify club cells as the main cell-of-origin for squamous transition. Through recapitulating lineage transition in organoid system, we identify JAK-STAT signaling, activated by EML4-ALK phase separation, significantly promotes squamous transition. Integrative study with scRNA-seq and immunostaining identify a plastic cell subpopulation in ALK-rearranged human LUAD showing squamous biomarker expression. Moreover, those relapsed ALK-rearranged LUAD show notable upregulation of squamous biomarkers. Consistently, mouse squamous tumors or LUAD with squamous signature display certain resistance to ALK inhibitor, which can be overcome by combined JAK1/2 inhibitor treatment. This study uncovers strong plasticity of ALK-rearranged tumors in orchestrating phenotypic transition and drug resistance and proposes a potentially effective therapeutic strategy.

Comprehensive analysis of clinicopathological profiles in adenosquamous carcinoma of the lung

OBJECTIVES

Adenosquamous carcinoma (ASC), an uncommon subtype within non-small cell lung cancer (NSCLC), manifests distinctive traits of aggressiveness, embodying a fusion of both adenocarcinoma (AC) and squamous cell carcinoma (SCC) components. The clinicopathological characteristics of distinct subtypes of ASC remain unclear.

METHODS

This retrospective study included 226 patients diagnosed with lung ASC who consecutively underwent surgical resection at Shanghai Pulmonary Hospital, Tongji University, between January 2015 and March 2021. Data regarding the clinical features and pathological features were collected.

RESULTS

Out of this study cohort, 125 patients exhibited AC-predominant ASC, while 81 had SCC-predominant ASC. No significant differences were observed between the two subgroups in terms of age, gender, smoking history, primary site, and T, N classification. AC-Predominant ASC displayed a higher susceptibility to genetic alterations compared to SCC-Predominant ASC (P=0.02). Additionally, we showed that irrespective of the predominant pathological subtype in ASC, when lymph node metastasis occurred, the lymph node biopsies were more likely to exhibit AC, and a chi-square test confirmed that the primary predominant pathological subtype was not associated with the lymph node metastasis subtype.

CONCLUSIONS

In conclusion, we describe an overview of ASC in the Chinese population, and upon stratifying into predominant pathological subgroups, we observed a higher frequency of driver gene mutations in AC-predominant ASC. We found that the AC component in ASC has a higher propensity for lymph node metastasis. These findings may suggest the predominant role of the AC component within the context of ASC.

Targeted therapy for rare lung cancers: Status, challenges, and prospects

Lung cancer causes the most cancer-related deaths worldwide. In recent years, molecular and immunohistochemical techniques have rapidly developed, further inaugurating an era of personalized medicine for lung cancer. The rare subset of lung cancers accounts for approximately 10%, each displaying distinct clinical characteristics. Treatments for rare lung cancers are mainly based on evidence from common counterparts, which may lead to unsolid clinical benefits considering intertumoral heterogeneity. The increasing knowledge of molecular profiling of rare lung cancers has made targeting genetic alterations and immune checkpoints a powerful strategy. Additionally, cellular therapy has emerged as a promising way to target tumor cells. In this review, we first discuss the current status of targeted therapy and preclinical models for rare lung cancers, as well as provide mutational profiles by integrating the results of existing cohorts. Finally, we point out the challenges and future directions for developing targeted agents for rare lung cancer.

[Correlation Analysis between Thyroid Function Abnormality and Efficacy in Patients with Advanced Non-small Cell Lung Cancer after Immunotherapy]

BACKGROUND

Thyroid function abnormality (TFA) is one of the common adverse reactions in patients with advanced non-small cell lung cancer (NSCLC) treated with immunotherapy, but the risk factors of TFA and its relationship with efficacy are not completely clear. The purpose of this study was to explore the risk factors of TFA and its relationship with efficacy in patients with advanced NSCLC after immunotherapy.

METHODS

The general clinical data of 200 patients with advanced NSCLC in The First Affiliated Hospital of Zhengzhou University from July 1, 2019 to June 31, 2021 were collected and analyzed retrospectively. χ² test and multivariate Logistic regression were used to explore the risk factors of TFA. Kaplan-Meier curve was drawn and Log-rank test was used for comparison between groups. Univariate and multivariate Cox analysis was used to explore the efficacy factors.

RESULTS

A total of 86 (43.0%) patients developed TFA. Logistic regression analysis showed that Eastern Cooperative Oncology Group Performance Status (ECOG PS), pleural effusion and lactic dehydrogenase (LDH) were factors influencing TFA (P<0.05). Compared with normal thyroid function group, the median progression-free survival (PFS) of patients in the TFA group was significantly longer (19.0 months vs 6.3 months, P<0.001), and the objective response rate (ORR) (65.1% vs 28.9%, P=0.020) and disease control rate (DCR) (100.0% vs 92.1%, P=0.020) of the TFA group were better than those of the normal thyroid function group. Cox regression analysis showed that ECOG PS, LDH, cytokeratin 19 fragment (CYFRA21-1) and TFA were factors influencing prognosis (P<0.05).

CONCLUSIONS

ECOG PS, pleural effusion and LDH may be risk factors affecting the occurrence of TFA and TFA may be a predictor of the efficacy of immunotherapy. Patients with advanced NSCLC who have TFA after immunotherapy may obtain better efficacy.

Comprehensive analyses of genomic features and mutational signatures in adenosquamous carcinoma of the lung

Adenosquamous carcinoma (ASC) of the lung is a relatively rare tumor with strong aggressiveness and poor prognosis. The analysis of mutational signatures is becoming routine in cancer genomics and has implications for pathogenesis, classification, and prognosis. However, the distribution of mutational signatures in ASC patients has not been evaluated. In this study, we sought to reveal the landscape of genomic mutations and mutational signatures in ASC. Next-generation sequencing (NGS) technology was used to retrieve genomic information for 124 ASC patients. TP53 and EGFR were the most prevalent somatic mutations observed, and were present in 66.9% and 54.8% of patients, respectively. CDKN2A (21%), TERT (21%), and LRP1B (18.5%) mutations were also observed. An analysis of gene fusion/rearrangement characteristics revealed a total of 64 gene fusions. The highest frequency of variants was determined for ALK fusions, with six ALK-EML4 classical and two intergenic ALK fusions, followed by three CD74-ROS1 fusions and one ROS1-SYN3 fusion. EGFR 19del (45.6%), and EGFR L858R (38.2%) and its amplification (29.4%) were the top three EGFR mutations. We extracted mutational signatures from NGS data and then performed a statistical analysis in order to search for genomic and clinical features that could be linked to mutation signatures. Amongst signatures cataloged at COSMIC, the most prevalent, high-frequency base changes were for C > T; and the five most frequent signatures, from highest to lowest, were 2, 3, 1, 30, and 13. Signatures 1 and 6 were determined to be associated with age and tumor stage, respectively, and Signatures 22 and 30 were significantly related to smoking. We additionally evaluated the correlation between tumor mutational burden (TMB) and genomic variations. We found that mutations ARID2, BRCA1, and KEAP1 were associated with high TMB. The homologous recombination repair (HRR) pathway-related gene mutation displayed a slightly higher TMB than those without mutations. Our study is the first to report comprehensive genomic features and mutational signatures in Chinese ASC patients. Results obtained from our study will help the scientific community better understand signature-related mutational processes in ASC.

Stepwise evolutionary genomics of early-stage lung adenocarcinoma manifesting as pure, heterogeneous and part-solid ground-glass nodules

BACKGROUND

This study was designed to unravel the genomic landscape and evolution of early-stage subsolid lung adenocarcinomas (SSN-LUADs) manifesting as pure ground-glass nodules (pGGNs), heterogeneous ground-glass nodules (HGGNs) and part-solid nodules (PSNs).

METHODS

Samples subjected to either broad-panel next-generation sequencing (NGS) or whole-exome sequencing (WES) were included. Clinicopathologic and genomic features were compared among pGGN, HGGN and PSN, while tumour evolutionary trajectories and mutational signatures were evaluated in the entire cohort.

RESULTS

In total, 247 SSN-LUAD samples subjected to broad-panel NGS and 125 to WES were identified. Compared with PSNs, HGGNs had significantly lower tumour mutation count (P < 0.001), genomic alteration count (P < 0.001), and intra-tumour heterogeneity (P = 0.005). Statistically significant upward trends were observed in alterations involving driver mutations and oncogenic pathways from pGGNs to HGGNs to PSNs. EGFR mutation was proved to be a key early event in the progression of SSN-LUADs, with subsequently two evolutionary trajectories involving either RBM10 or TP53 mutation in the cancer-evolution models.

CONCLUSIONS

This study provided evidence for unravelling the previously unknown genomic underpinnings associated with SSN-LUAD evolution from pGGN to HGGN to PSN, proving that HGGN was an intermediate SSN form between pGGN and PSN genetically.

PD-L1 Over-Expression Varies in Different Subtypes of Lung Cancer: Will This Affect Future Therapies?

Programmed death-ligand (PD-L) 1 and 2 are ligands of programmed cell death 1 (PD-1) receptor. They are members of the B7/CD28 ligand-receptor family and the most investigated inhibitory immune checkpoints at present. PD-L1 is the main effector in PD-1-reliant immunosuppression, as the PD-1/PD-L pathway is a key regulator for T-cell activation. Activation of T-cells warrants the upregulation of PD-1 and production of cytokines which also upregulate PD-L1 expression, creating a positive feedback mechanism that has an important role in the prevention of tissue destruction and development of autoimmunity. In the context of inadequate immune response, the prolonged antigen stimulation leads to chronic PD-1 upregulation and T-cell exhaustion. In lung cancer patients, PD-L1 expression levels have been of special interest since patients with non-small cell lung cancer (NSCLC) demonstrate higher levels of expression and tend to respond more favorably to the evolving PD-1 and PD-L1 inhibitors. The Food and Drug Administration (FDA) has approved the PD-1 inhibitor, pembrolizumab, alone as front-line single-agent therapy instead of chemotherapy in patients with NSCLC and PD-L1 ≥1% expression and chemoimmunotherapy regimens are available for lower stage disease. The National Comprehensive Cancer Network (NCCN) guidelines also delineate treatment by low and high expression of PD-L1 in NSCLC. Thus, studying PD-L1 overexpression levels in the different histological subtypes of lung cancer can affect our approach to treating these patients. There is an evolving role of immunotherapy in the other sub-types of lung cancer, especially small cell lung cancer (SCLC). In addition, within the NSCLC category, squamous cell carcinomas and non-G12C KRAS mutant NSCLC have no specific targetable therapies to date. Therefore, assessment of the PD-L1 expression level among these subtypes of lung cancer is required, since lung cancer is one of the few malignances wherein PD-L1 expression levels is so crucial in determining the role of immunotherapy. In this study, we compared PD-L1 expression in lung cancer according to the histological subtype of the tumor.

Clinicopathological characteristics and prognosis of resectable lung adenosquamous carcinoma: a population-based study of the SEER database

OBJECTIVE

Adenosquamous carcinoma is a rare subtype of non-small cell lung cancer characterized by aggressive behavior, with combination of adenocarcinoma and squamous cell carcinoma components. The clinicopathological characteristics and prognosis of resectable adenosquamous carcinoma are incompletely understood and this study aimed to depict those in a large population.

METHODS

A total of 805 adenosquamous carcinoma, 7875 squamous cell carcinoma and 23 957 adenocarcinoma patients who underwent lobectomy or sublobectomy were queried from the Surveillance, Epidemiology, and End Results database (2010-17). Clinicopathological characteristics of adenosquamous carcinoma patients were compared with those of squamous cell carcinoma and adenocarcinoma patients. Prognostic factors were identified by univariable and multivariable Cox regression analyses. Propensity score matching was applied to reduce confounding effects.

RESULTS

Adenosquamous carcinoma was associated with higher pleural invasion incidence and poorer differentiation compared with squamous cell carcinoma or adenocarcinoma (P values < 0.001). The independent risk factors of cancer-specific survival of adenosquamous carcinoma patients were increasing age, male sex, invading through visceral pleura, poor differentiation and higher stage. Stage IB adenosquamous carcinoma patients whose tumor invaded through visceral pleura had significantly worse survival than those not (P = 0.003). Adenosquamous carcinoma patients had worse survival compared with squamous cell carcinoma (5-year-survival: 64.55 vs. 69.09%, P = 0.003) and adenocarcinoma (5-year-survival: 64.55 vs. 76.79%, P < 0.001) patients before match. And this difference persisted after match.

CONCLUSIONS

Resectable adenosquamous carcinoma patients had higher pleural invasion incidence, poorer differentiation and worse survival compared with squamous cell carcinoma and adenocarcinoma patients. Visceral pleural invasion status and differentiation grade were vital prognostic factors of adenosquamous carcinoma patients on the basis of stage.

Developing an Immune-Related Signature for Predicting Survival Rate and the Response to Immune Checkpoint Inhibitors in Patients With Glioma

Background: Glioma is one of the most aggressive cancer types affecting the central nerve system, with poor overall survival (OS) rates. The present study aimed to construct a novel immune-related signature to predict prognosis and the efficiency of immunotherapy in patients with glioma.

Methods: The mRNA expression data and other clinical information of patients with glioblastoma multiforme (GBM) and low grade glioma (LGG) were obtained from The Cancer Genome Atlas and Chinese Glioma Genome Atlas databases. The immune-related genes were obtained from the Immunology Database and Analysis Portal database. Subsequently, an immune-related signature was created following the results obtained from the Least Absolute Shrinkage and Selection Operator regression model. To validate the predictability of the signature, Kaplan-Meier survival curves and time-dependent receiver operating characteristic curves were created. Moreover, both univariate and multivariate analyses were carried out using the OS between this signature and other clinicopathologic factors, and a nomogram was constructed. In addition, the association between signature, immune cell infiltration, tumor mutation burden and immunophenoscore were determined.

Results: Results of the present study using 118 GBM and LGG samples uncovered 15 immune-related genes that were also differently expressed in glioma samples. These were subsequently used to construct the immune-related signature. This signature exhibits the ability to predict prognosis, the infiltration of immune cells in the tumor microenvironment and the response of patients with glioma to immunotherapy.

Conclusion: Results of the present study demonstrated that the aforementioned novel immune-related signature may accurately predict prognosis and the response of patients with glioma to immunotherapy.

Relationship between tumor mutational burden, gene mutation status, and clinical characteristics in 340 cases of lung adenocarcinoma

Tumor mutational burden (TMB) is an emerging predictive marker of response to immune checkpoint inhibitor therapies. We evaluated the correlation between clinical indicators and high-throughput sequencing results and TMB in lung adenocarcinoma patients, with the aim of finding simpler and more economical factors as surrogate markers for TMB. The medical records, next-generation sequencing data, and immunohistochemistry results of 340 lung adenocarcinoma patients who were admitted to the First Affiliated Hospital of Zhengzhou University between 2019 and 2020 were collected. The mutated genes were screened for, and the obtained mutated genes were subjected to functional enrichment analysis using R software. A protein-protein interaction (PPI) network was also constructed, and significant modules in the network were identified. Gene Ontology (GO) analyses were performed for the core genes. Univariate and multivariate correlation analyses were performed to judge the correlation between gene mutations and TMB. Genes with a junction mutation rate >1 were selected to construct PPI network and 13 high-connection core genes were screened. The results of GO enrichment analysis showed that the biological processes related to mutant core genes mainly included mitotic cell cycle and cell aging. Subsequently, ATM (p = 0.006) and PIK3CA (p = 0.008) mutation positivity were identified by univariate and multivariate correlation analysis, while TP53 (p = 0.003) and EGFR (p = 0.008) mutation negativity were significantly associated with elevated TMB. The results of this study demonstrate that ATM- and PIK3CA-positive and EGFR-negative mutation status are strongly associated with high levels of TMB and have the potential to be predictive biomarkers of response to immune checkpoint inhibitors in lung adenocarcinoma patients.

Association of thyroid function abnormality and prognosis in non-small-cell lung cancer patients treated with PD-1 inhibitors

Background: Thyroid function abnormality (TFA) is one of the most common toxicities in non-small-cell lung cancer (NSCLC) patients receiving immune checkpoint inhibitors. However, the risk factors related to TFA and the relationship between TFA and prognosis in NSCLC are not fully clarified. Methods: We conducted a retrospective study of patients with advanced NSCLC who were treated with PD-1 inhibitors in Huzhou Central Hospital. Thyroid function test was carried out using electrochemiluminescent bridging immunoassay. The association between TFA and clinical outcome was investigated. Results: A total of 273 patients were included in this study. Patients who experienced TFA had longer progression-free survival (21.9 vs 6.4 months; p < 0.001) and overall survival (44.6 vs 24.1 months; p = 0.02) than patients without TFA. After multivariate analysis, TFA was an independent prognostic factor for progression-free and overall survival (p < 0.05). Conclusion: TFA is associated with better outcome in NSCLC patients who receive immunotherapy.