Genomic origin and EGFR-TKI treatments of pulmonary adenosquamous carcinoma

Case report: A patient with EGFR L861Q positive adenosquamous lung carcinoma transforming into large cell neuroendocrine cancer after treatment with Almonertinib

Almonertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor, is selective for both epidermal growth factor receptor tyrosine kinase inhibitor-sensitizing and T790M resistance mutations. However, resistance to the third-generation EGFR-TKIs is still inevitable. Econdary EGFR mutations, and bypass pathway activation have been reported with Almonertinib therapy. This article presents a rare case report of a patient with EGFR L861Q positive adenosquamous lung carcinoma who transformed into large cell neuroendocrine carcinoma following treatment with Almonertinib. The patient exhibited disease progression 8 months after initiating Almonertinib treatment, and a blood genetic test revealed mutations in EGFR L861Q and EGFR L858R. A subsequent lung biopsy after progression confirmed the diagnosis of large cell neuroendocrine carcinoma, and subsequently treatment with cisplatin and etoposide was effective. Transformation into neuroendocrine carcinoma is one of the mechanisms behind resistance to Almonertinib in adenosquamous lung carcinoma. EGFR mutations may persist even after transformation into neuroendocrine carcinoma. For non-small cell lung cancer patients undergoing Almonertinib therapy, this case report emphasizes the importance of performing a timely pathological biopsy upon the emergence of resistance.

Precise identification of somatic and germline variants in the absence of matched normal samples

Somatic variants play a crucial role in the occurrence and progression of cancer. However, in the absence of matched normal controls, distinguishing between germline and somatic variants becomes challenging in tumor samples. The existing tumor-only genomic analysis methods either suffer from limited performance or insufficient interpretability due to an excess of features. Therefore, there is an urgent need for an alternative approach that can address these issues and have practical implications. Here, we presented OncoTOP, a computational method for genomic analysis without matched normal samples, which can accurately distinguish somatic mutations from germline variants. Reference sample analysis revealed a 0% false positive rate and 99.7% reproducibility for variant calling. Assessing 2864 tumor samples across 18 cancer types yielded a 99.8% overall positive percent agreement and a 99.9% positive predictive value. OncoTOP can also accurately detect clinically actionable variants and subclonal mutations associated with drug resistance. For the prediction of mutation origins, the positive percent agreement stood at 97.4% for predicting somatic mutations and 95.7% for germline mutations. High consistency of tumor mutational burden (TMB) was observed between the results generated by OncoTOP and tumor-normal paired analysis. In a cohort of 97 lung cancer patients treated with immunotherapy, TMB-high patients had prolonged PFS (P = .02), proving the reliability of our approach in estimating TMB to predict therapy response. Furthermore, microsatellite instability status showed a strong concordance (97%) with polymerase chain reaction results, and leukocyte antigens class I subtypes and homozygosity achieved an impressive concordance rate of 99.3% and 99.9% respectively, compared to its tumor-normal paired analysis. Thus, OncoTOP exhibited high reliability in variant calling, mutation origin prediction, and biomarker estimation. Its application will promise substantial advantages for clinical genomic testing.

Clinicopathological Features and Survival Outcomes of Resected Lung Adenosquamous Carcinoma: Results From a Nationwide Japanese Registry Data

OBJECTIVES

The objective of this study was to clarify the clinicopathological features and prognostic factors of resected lung adenosquamous carcinoma (ASC) using a nationwide multi-institutional database.

METHODS

We retrospectively reviewed the records of 15,542 patients who underwent complete R0 resection for ASC (n = 326), adenocarcinoma (AC, n = 11,820), or squamous cell carcinoma (SC, n = 3396) from a Japanese lung cancer registry in 2010. To reduce the selection bias, an inverse probability of treatment weighting (IPTW) method using a propensity score was implemented.

RESULTS

The ASC group showed worse recurrence-free and overall survival (RFS and OS) than both the AC and SC groups (5-year OS: 57.5% in ASC, 83.9% in AC [< 0.001], and 62.3% in SC [P = .086]). In multivariate analyses, prognostic factors that affected OS for ASC included male, p-stage II-III, and postoperative complications within 30 days (grade ≥ 3 in the Clavien-Dindo classification). The sensitizing EGFR mutation was detected in 28 (21.5%) of 130 screened patients with ASC, but it did not affect either RFS, OS, or postrecurrence survival. Although more patients in the ASC group received adjuvant chemotherapy compared to the AC and SC groups, both multivariate and IPTW-adjusted analyses did not show positive impact of adjuvant chemotherapy on RFS and OS in ASC.

CONCLUSIONS

In this nationwide registry study, lung ASC was more aggressive than both AC and SC. No apparent survival impact of conventional adjuvant chemotherapy prompted us to investigate novel adjuvant strategies to optimize survival outcomes.

Efficacy of epidermal growth factor receptor-tyrosine kinase inhibitor for lung adenosquamous cell carcinoma harboring EGFR mutation: a retrospective study and pooled analysis

Objectives

To explore the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) on lung adenosquamous cell carcinoma (ASC) with EGFR mutation.

Methods

Efficacy of EGFR-TKIs in the treatment of advanced or recurrent lung ASC with EGFR mutations was assessed retrospectively in 44 patients. Pooled analysis of 74 patients using EGFR-TKIs, including 30 patients selected from 11 publications, was conducted.

Results

In our retrospective research, patients treated with EGFR-TKI in ASC with EGFR mutations had objective response rate (ORR) of 54.5%, disease control rate (DCR) of 79.5%, median progression free survival (mPFS) of 8.8 months, and median overall survival (mOS) of 19.43 months, respectively. A pooled analysis reveals ORR, DCR, mPFS, and mOS are, respectively, 63.4%, 85.9%, 10.00 months, and 21.37 months for ASC patients. In patients with deletions in exon 19 and exon 21 L858R mutations, mPFS (11.0 versus 10.0 months, P=0.771) and mOS (23.67 versus 20.33 months, P=0.973) were similar. Erlotinib or gefitinib-treated patients had an overall survival trend that was superior to that of icotinib-treated patients.

Conclusions

ASC harboring EGFR mutations can be treated with EGFR-TKI in a similar manner to Adenocarcinoma (ADC) harboring EGFR mutations. There is still a need for further investigation to identify the separate roles of ASC's two components in treating EGFR.

TET2-STAT3-CXCL5 nexus promotes neutrophil lipid transfer to fuel lung adeno-to-squamous transition

Phenotypic plasticity is a rising cancer hallmark, and lung adeno-to-squamous transition (AST) triggered by LKB1 inactivation is significantly associated with drug resistance. Mechanistic insights into AST are urgently needed to identify therapeutic vulnerability in LKB1-deficient lung cancer. Here, we find that ten-eleven translocation (TET)-mediated DNA demethylation is elevated during AST in KrasLSL-G12D/+; Lkb1L/L (KL) mice, and knockout of individual Tet genes reveals that Tet2 is required for squamous transition. TET2 promotes neutrophil infiltration through STAT3-mediated CXCL5 expression. Targeting the STAT3-CXCL5 nexus effectively inhibits squamous transition through reducing neutrophil infiltration. Interestingly, tumor-infiltrating neutrophils are laden with triglycerides and can transfer the lipid to tumor cells to promote cell proliferation and squamous transition. Pharmacological inhibition of macropinocytosis dramatically inhibits neutrophil-to-cancer cell lipid transfer and blocks squamous transition. These data uncover an epigenetic mechanism orchestrating phenotypic plasticity through regulating immune microenvironment and metabolic communication, and identify therapeutic strategies to inhibit AST.

Postoperative ctDNA in indicating the recurrence risk and monitoring the effect of adjuvant therapy in surgical non-small cell lung cancer

BACKGROUND

Circulating tumor DNA (ctDNA) has emerged as a potential novel biomarker to predict molecular residual disease (MRD) in lung cancer after definitive treatment. Herein, we investigated the value of ctDNA in prognosing risk of relapse and monitoring the effect of adjuvant therapy in surgical non-small cell lung cancer (NSCLC).

METHODS

We enrolled 58 NSCLC patients in a real-world setting, and 58 tumor tissues and 325 plasma samples were analyzed. Tumor tissues and plasma samples were subjected to targeted next-generation sequencing (NGS) of 1021 cancer-related and ultra-deep targeted NGS covering 338 genes, respectively.

RESULTS

ctDNA was detected in 31.0% of cases at the first postoperative time, which was associated with advanced tumor stage, T stage and KEAP1 or GRIN2A mutations in tissues. ctDNA positivity at landmark and longitudinal indicated the shorter disease-free survival. For patients with ctDNA positivity at the first postoperative time, regardless of adjuvant therapy, all patients who were persistently ctDNA positive during postoperative surveillance had disease recurrence. Among the patients who were ctDNA negative, only two patients (15.4%, 2/13) receiving adjuvant therapy relapsed, while one patient (50.0%, 1/2) without adjuvant therapy relapsed. For the first postoperative ctDNA negative patients, the recurrence rate of patients with adjuvant therapy was and higher than without adjuvant therapy (22.6% [7/31] vs. 11.1% [1/9]). The patients who became ctDNA positive may also benefit from intervention therapy.

CONCLUSION

Postoperative ctDNA is a prognostic marker, and ctDNA-detection may facilitate personalized adjuvant therapy, and applying adjuvant therapy to the patients with detectable ctDNA could bring clinical benefits for them.

Genetic mutation profiling reveals biomarkers for targeted therapy efficacy and prognosis in non-small cell lung cancer

Introduction

The genetic heterogeneity of non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations may affect clinical responses and outcomes to EGFR tyrosine kinase inhibitors (EGFR-TKIs). This study aims to investigate the genomic factors that influence the efficacy and clinical outcomes of first-line, second-line and third-line treatments in NSCLC and explore the heterogeneity of resistance mechanisms.

Materials and methods

This real-world study comprised 65 patients with EGFR mutant NSCLC. Molecular alterations were detected using a customized DNA panel before and after administering targeted therapy. The efficacy and prognosis of each treatment line were evaluated.

Results

In first-generation EGFR-TKIs treatment, gefitinib showed favorable efficacy compared to icotinib and erlotinib, particularly in patients with EGFR L858R mutations. The resistance mechanisms to first-generation EGFR-TKIs varied among different EGFR mutation cohorts and different first-generation EGFR-TKIs. In second-line EGFR-TKIs treatment, EPH receptor A3 (EPHA3), IKAROS family zinc finger 1 (IKZF1), p21 (RAC1) activated kinase 5 (PAK5), DNA polymerase epsilon, catalytic subunit (POLE), RAD21 cohesin complex component (RAD21) and RNA binding motif protein 10 (RBM10) mutations were markedly associated with poorer progression-free survival (PFS). Notably, EPHA3, IKZF1 and RBM10 were identified as independent predictors of PFS. The mechanisms of osimertinib resistance exhibited heterogeneity, with a higher proportion of non-EGFR-dependent resistant mutations. In third-line treatments, the combination of osimertinib and anlotinib demonstrated superior efficacy compared to other regimens. Glutamate ionotropic receptor NMDA type subunit 2A (GRIN2A) mutation was an independent risk indicator of shorter OS following third-line treatments.

Conclusions

Comprehending the tumor evolution in NSCLC is advantageous for assessing the efficacy and prognosis at each stage of treatment, providing valuable insights to guide personalized treatment decisions for patients.

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.

A novel approach to evaluation of tumor response for advanced pulmonary adenocarcinoma using the intertumoral heterogeneity response score

Treatment response and prognosis estimation in advanced pulmonary adenocarcinoma are challenged by the significant heterogeneity of the disease. The current Response Evaluation Criteria in Solid Tumors (RECIST) criteria, despite providing a basis for solid tumor response evaluation, do not fully encompass this heterogeneity. To better represent these nuances, we introduce the intertumoral heterogeneity response score (THRscore), a measure built upon and expanding the RECIST criteria. This retrospective study included patients with 3-10 measurable advanced lung adenocarcinoma lesions who underwent first-line chemotherapy or targeted therapy. The THRscore, derived from the coefficient of variation in size for each measurable tumor before and 4-6 weeks posttreatment, unveiled a correlation with patient outcomes. Specifically, a high THRscore was associated with shorter progression-free survival, lower tumor response rate, and a higher tumor mutation burden. These associations were further validated in an external cohort, confirming THRscore's effectiveness in stratifying patients based on progression risk and treatment response, and enhancing the utility of RECIST in capturing complex tumor behaviors in lung adenocarcinoma. These findings affirm the promise of THRscore as an enhanced tool for tumor response assessment in advanced lung adenocarcinoma, extending the RECIST criteria's utility.

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

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

Adenosquamous carcinoma of the liver: The challenge of diagnosis

Adenosquamous carcinoma of the liver is extremely rare. We report a case of adenosquamous carcinoma in the intrahepatic bile duct of a 56-year-old woman who complained of persistent abdominal pain, shivering and hyperthermia. Computed tomography demonstrated a solid-cystic neoplasm in segment 5/6/8 of the liver with a gradual enhancement pattern in the solid area. However, postoperative pathological examination showed adenosquamous carcinoma of intrahepatic bile duct.

Radiomics and deep learning models to differentiate lung adenosquamous carcinoma: A multicenter trial

Adenosquamous carcinoma (ASC) is frequently misdiagnosed or overlooked in clinical practice due to its dual histological components and potential transformation from either adenocarcinoma (ADC) or squamous cell carcinoma (SCC). Our study aimed to differentiate ASC from ADC and SCC by incorporating features of enhanced CTs and clinical characteristics to build radiomics and deep learning models. The classification models were trained in Xiangya Hospital and validated in two other independent hospitals. The areas under the receiver operating characteristic curves (AUC), accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were used to estimate the performance. The optimal three-class classification model achieved a maximum AUC of 0.89 and accuracy of 0.81 in external validation sets, AUC of 0.99 and accuracy of 0.99 in the internal test set. These findings highlight the efficacy of our models in differentiating ASC, providing a non-invasive, timely, and accurate diagnostic approach before and during the treatment.

Clonal dynamics and Stereo-seq resolve origin and phenotypic plasticity of adenosquamous carcinoma

The genomic origin and development of the biphasic lung adenosquamous carcinoma (ASC) remain inconclusive. Here, we derived potential evolutionary trajectory of ASC through whole-exome sequencing, Stereo-seq, and patient-derived xenografts. We showed that EGFR and MET activating mutations were the main drivers in ASCs. Phylogenetically, these drivers and passenger mutations found in both components were trunk clonal events, confirming monoclonal origination. Comparison of multiple lesions also revealed closer genomic distance between lymph node metastases and the ASC component with the same phenotype. However, as mutational signatures of EGFR-positive lung squamous carcinomas (LUSCs) were more comparable to EGFR-positive ASCs than to wild-type LUSCs, we postulated different origination of these LUSCs, with ASC being the potential intermediate state of driver-positive LUSCs. Spatial transcriptomic profiling inferred transformation from adenocarcinoma to squamous cell carcinoma, which was then histologically captured in vivo. Together, our results explained the development of ASC and provided insights into future clinical decisions.

Case Report: Response to ALK-TKIs in a metastatic lung cancer patient with morphological heterogeneity and consistent molecular features

Lung adenosquamous carcinoma (ASC) is a rare heterogeneous tumor containing two distinct components of adenocarcinoma (ADC) and squamous cell carcinoma (SQCC). The limited biopsy sampling of the primary tumor might have overlooked either the ADC component or the SQCC component, resulting in a misdiagnosis of pure histology. Genotyping for driver mutations is now routinely performed in clinical settings to identify actionable oncogenic mutations and gene arrangements. Additionally, somatic mutations can potentially serve as a marker of clonal relationships. We report a rare case of ASC lung cancer, in which metastases were identified as ADC, while the primary was initially diagnosed as SQCC based on a fibrobronchoscope brush biopsy. The primary and metastatic tumors shared ALK rearrangement and other mutations support they were derived from a single clone origin. Our hypothesis is that the primary tumor contained a minor component of ADC that was not present in the histologic sections of lung biopsy. After sequential ALK-tyrosine kinase inhibitor (TKI) targeted therapy, both the patient's primary lung tumor and the site of metastatic subcutaneous nodules decreased in size, with the metastatic sites demonstrating more noticeable shrinkage. However, after 11 months of targeted therapy, the patient was found to be resistant to ALK-TKIs. Subsequently, the patient's respiratory status deteriorated rapidly, and a cycle of immunotherapy and chemotherapy did not show efficacy. To the best of our knowledge, this is a very rare case of lung ASC, disseminated metastasizing, with distinct morphology between the primary and metastases. Different therapeutic effects of ALK-TKIs were observed in two different morphological sites, with the metastatic cutaneous lesions shrinking more significantly than the primary lung lesions, though they both harbor the same EML4-ALK rearrangement. This case may provide diagnostic and therapeutic insights into lung 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.

D-1553 (Garsorasib), a Potent and Selective Inhibitor of KRASG12C in Patients With NSCLC: Phase 1 Study Results

INTRODUCTION

D-1553 (garsorasib) is a potent and selective oral KRASG12C inhibitor. We report results from a phase I dose-escalation and dose-expansion study of D-1553 in patients with KRAS G12C-mutated NSCLC in multiple sites in the People's Republic of China.

METHODS

Patients with KRAS G12C-mutated NSCLC have administrated D-1553 600 mg orally once daily, 800 mg once daily, 1200 mg once daily, 400 mg twice a day, or 600 mg twice a day in dose escalation. In dose-expansion, all patients received 600 mg twice a day. The safety, pharmacokinetics, and efficacy of D-1553 were evaluated.

RESULTS

Among a total of 79 treated patients, 75 patients (94.9%) reported treatment-related adverse events with 30 patients experiencing grade 3 or 4 events (38.0%). Most of the adverse events were manageable and the patients tolerated the study treatment well. Among 74 patients assessable for efficacy analysis, 30 patients had a partial response and 38 had stable disease with a confirmed objective response rate (ORR) and disease control rate (DCR) of 40.5% and 91.9%, respectively. The median progression-free survival was 8.2 months, and the median duration of response was 7.1 months. Among 62 patients assessable for response at the recommended phase 2 dose, partial response occurred in 24 patients (ORR, 38.7%) and stable disease in 32 patients (DCR, 90.3%). The median progression-free survival and duration of response were 7.6 months and 6.9 months, respectively. In patients with brain metastasis, ORR and DCR were 17% and 100%, respectively.

CONCLUSIONS

D-1553 represents a promising therapeutic option for patients with KRAS G12C-mutated NSCLC with a well-tolerated safety profile and encouraging antitumor activity.

Oxidative stress-triggered Wnt signaling perturbation characterizes the tipping point of lung adeno-to-squamous transdifferentiation

Lkb1 deficiency confers the Kras-mutant lung cancer with strong plasticity and the potential for adeno-to-squamous transdifferentiation (AST). However, it remains largely unknown how Lkb1 deficiency dynamically regulates AST. Using the classical AST mouse model (Kras ^LSL-G12D/+;Lkb1^flox/flox, KL), we here comprehensively analyze the temporal transcriptomic dynamics of lung tumors at different stages by dynamic network biomarker (DNB) and identify the tipping point at which the Wnt signaling is abruptly suppressed by the excessive accumulation of reactive oxygen species (ROS) through its downstream effector FOXO3A. Bidirectional genetic perturbation of the Wnt pathway using two different Ctnnb1 conditional knockout mouse strains confirms its essential role in the negative regulation of AST. Importantly, pharmacological activation of the Wnt pathway before but not after the tipping point inhibits squamous transdifferentiation, highlighting the irreversibility of AST after crossing the tipping point. Through comparative transcriptomic analyses of mouse and human tumors, we find that the lineage-specific transcription factors (TFs) of adenocarcinoma and squamous cell carcinoma form a "Yin-Yang" counteracting network. Interestingly, inactivation of the Wnt pathway preferentially suppresses the adenomatous lineage TF network and thus disrupts the "Yin-Yang" homeostasis to lean towards the squamous lineage, whereas ectopic expression of NKX2-1, an adenomatous lineage TF, significantly dampens such phenotypic transition accelerated by the Wnt pathway inactivation. The negative correlation between the Wnt pathway and AST is further observed in a large cohort of human lung adenosquamous carcinoma. Collectively, our study identifies the tipping point of AST and highlights an essential role of the ROS-Wnt axis in dynamically orchestrating the homeostasis between adeno- and squamous-specific TF networks at the AST tipping point.

Case report: Dramatic response to alectinib in a lung adenosquamous carcinoma patient harbouring a novel CPE-ALK fusion

Lung Adenosquamous carcinoma (ASC) is a rare histological subtype of lung cancer accounting for 0.4%–4% of all lung cancers. ASC is generally considered to be an aggressive cancer with poor prognosis. There is no specific standard treatment for ASC, and current treatment of ASC is relied on the guideline for non-small cell lung cancer (NSCLC). To date, only sporadic canonical EML4-ALK fusions have been reported in ASC patients, and the efficiency of ALK-TKI is still unclear in non-canonical ALK fusion positive ASC patients. Here we describe the case of a stage IV ASC patient harboring a novel CPE-ALK fusion detected via 74 genes panel analysis. Interestingly, the TP53 was wild-type and no another somatic mutation was found within 74 genes. In addition, immunohistochemical staining (IHC) also supports an oncogenic role for the CPE-ALK fusion. Based on these findings, the patient received alectinib 600 mg twice daily. After 4 months on treatment the patients achieved a radiological partial response (PR) and his symptoms were significantly relieved. Imaging showed that lesions of the patient were reduced, and the clinical evaluation was partial response (PR). To the best of our knowledge, this is the first report of a dramatic tumor response to alectinib in a patient with ASC harboring a CPE-ALK fusion. In addition, targeted NGS analysis may improve detection of ALK fusion in routine practice.

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 characterization of genomic and radiologic features reveals distinct driver patterns of RTK/RAS pathway in ground-glass opacity pulmonary nodules

Ground-glass opacity (GGO)-associated pulmonary nodules have been known as a radiologic feature of early-stage lung cancers and exhibit an indolent biological behavior. However, the correlation between driver genes and radiologic features as well as the immune microenvironment remains poorly understood. We performed a custom 1021-gene panel sequencing of 334 resected pulmonary nodules presenting as GGO from 262 Chinese patients. A total of 130 multiple pulmonary nodules were sampled from 58 patients. Clinical-pathologic and radiologic parameters of these pulmonary nodules were collected. Immunohistochemistry (IHC) and multiplex immunofluorescent staining (mIF) were applied to analyze proliferation and immune cell markers of GGO-associated pulmonary nodules. Compared with pure GGO nodules, mixed GGO nodules were enriched for invasive adenocarcinoma (IAC) (182/216 vs 73/118, P &lt; .001). Eighty-eight percent (294/334) of GGO-associated nodules carried at least one mutation in EGFR/ERBB2/BRAF/KRAS/MAP2K1 of the RTK/RAS signaling pathway, and the alterations in these driver genes were mutually exclusive. The analysis of multifocal pulmonary nodules from the same patient revealed evidence of functional convergence on RTK/RAS pathways. Nodules with ERBB2/BRAF/MAP2K1 mutations tended to be more indolent than those with EGFR and KRAS mutations. IHC and mIF staining showed that KRAS-mutant GGO nodules displayed higher infiltration of CD4+ T cell and CD8+ T cell as well as stronger proliferation and immune inhibitory signals. Our study demonstrates a driver landscape of radiologically detectable GGO-associated pulmonary nodules in Chinese patients and supports that different driver patterns in RTK/RAS pathway are corresponding to different radiologic features.

EGFR mutations and high PD-L1 expression of lung squamous cell carcinoma patients achieving pCR following neoadjuvant immuno-chemotherapy: Case report

The treatment of lung cancer has fully entered the era of immunotherapy, which has significantly elevated the survival rate of patients with advanced non-small cell lung cancer (NSCLC), thus shedding light on resectable NSCLC. Previous clinical trial data suggested that neoadjuvant immuno-chemotherapy obtained a significant objective response rate (ORR) and disease control rate (DCR). Here, a case that achieved an excellent outcome following neoadjuvant immuno-chemotherapy was reported. The patient admitted to our hospital was 58 years old, female, with a rare case of stage IB lung squamous cell carcinoma (LUSC) harboring both epidermal growth factor receptor (EGFR) p.L858R mutations and high expression of programmed death ligand-1 (PD-L1) (tumor proportion score (TPS)=80%). Her tumor substantially shrunk following two cycles of neoadjuvant immuno-chemotherapy. The patient successively received single-port right upper thoracoscopic lobectomy + mediastinal lymph node dissection, which attained pathologic complete response (pCR). Additionally, the patient had grade 2 myelosuppression during the two cycles, which was treated with polyethylene glycol recombinant human granulocyte colony-stimulating factor (rhG-CSF). The patient was discharged uneventfully without any procedure-related complications. Two courses of adjuvant immuno-chemotherapy were administered postoperatively, leaving the patient in good physical condition at the 5-month follow-up visit. This case provided evidence for the feasibility and effectiveness of neoadjuvant immuno-chemotherapy in treating early-stage LUSC with EGFR mutations and high expression of PD-L1. However, randomized and multi-center controlled trials are required to validate the findings.

Case report: A case report and literature review about Pathological transformation of lung adenosquamous cell carcinoma

Background

Lung adenosquamous carcinoma is a relatively rare pathological type in lung cancer. The incidence of gene mutation is lower than that of lung adenocarcinoma. However, the cases of pathological transformation after targeted treatment of EGFR gene mutation are more rare.

Case introduction

A 55 year old female was diagnosed with lung cancer and underwent surgical treatment.The pathology suggested adenosquamous cell carcinoma. Genetic test was EGFR-L858R. After surgery, she was treated with gefitinib targeted therapy. After 2 years of surgery, she developed brain metastasis. surgery was performed again. The pathology suggested squamous cell carcinoma. She continued to take gefitinib targeted therapy orally. After one month later since brain metastasis, she was found to have heart cavity metastasis and surgery was performed for the third time. Besides, the pathology suggested adenosquamous cell carcinoma. Genetic test was EGFR-p E746_ A750del, T790M (-), and we replaced with the second-generation EGFR-TKI afatinib targeted therapy. Up to now, no recurrence or metastasis has been found.

Conclusion

We now report a rare case of lung adenosquamous carcinoma with pathological transformation during targeted therapy, which is intended to provide therapeutic ideas for the treatment of lung adenosquamous carcinoma in clinical practice. In addition, we reviewed previously reported tumor heterogeneity in the literature.

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.

Heterogeneity of tumor immune microenvironment and real-world analysis of immunotherapy efficacy in lung adenosquamous carcinoma

Lung adenosquamous carcinoma (ASC) is an uncommon histological subtype. We aimed to characterize the tumor immune microenvironment (TIME) in lung ASC and estimate patient response to immune checkpoint inhibitors (ICIs), which have never been systematically investigated. In cohort I, we collected 30 ASCs from a single center for analysis of TIME characteristics, including immuno-phenotyping, tumor mutation burden (TMB), T-cell receptor (TCR) repertoires, tumor-infiltrating lymphocytes (TILs), and immune checkpoint expression. Twenty-two (73.3%) patients were EGFR-positive. The TIME was defined by immune-excluded (60%) and immune-desert phenotype (40%). Strikingly, programmed cell death-ligand 1 (PD-L1) and programmed cell death-1 (PD-1) were predominantly expressed in squamous cell carcinoma components (SCCCs) versus adenocarcinoma components (ACCs), where enhanced CD4⁺ FOXP3⁺ regulatory T cell and attenuated CD57⁺ natural killer cell infiltration were present, consistent with a landscape of fewer innate immune cells, more immunosuppressive cells. SCCCs had higher TMB, higher TCR clonality, and lower TCR diversity than ACC. In cohort III, the efficacy of ICI-based therapy was estimated using a real-world data of 46 ASCs from 11 centers. Majority of 46 patients were driver genes negative and unknown mutation status, 18 (39%) and 18 (39%), respectively. The overall objective response rate of 28%, median progression-free survival of 6.0 months (95% confidence interval [CI] 4.3–7.7), and median overall survival of 24.7 months (95% CI 7.2–42.2) were observed in the ICI-based treatment. This work ascertains suppressive TIME in lung ASC and genetic and immuno-heterogeneity between ACCs and SCCCs. Lung ASC patients have a moderate response to ICI-based immunotherapy.

Neoadjuvant ceritinib treatment in ALK-rearranged locally advanced adenosquamous carcinoma: A case report

Here, we first report a case of neoadjuvant ceritinib for locally advanced lung adenosquamous carcinoma. In this study, a locally advanced adenosquamous carcinoma (ASC) patient with EML4-ALK fusion who achieved a partial response with neoadjuvant ceritinib treatment after a cycle of neoadjuvant chemotherapy did not show significant efficacy. A complete surgical resection was performed with mild adhesions and a small amount of bleeding intraoperatively. The EML4-ALK fusion was detected by targeted next-generation sequencing (NGS) in both pretreatment biopsy and the postoperative tissue specimens with a dramatic decrease in the allele frequency (26.2% [pre]-2.3% [post]). Pathological examination of the postoperative specimens indicated a diagnosis of ASC but the proportions of adenocarcinoma and squamous cell carcinoma cells in the primary lung tumor and metastatic lymph node site were different, suggesting the various responses to ceritinib. Thus, with the case presented here, we provide the clinical evidence for ALK-positive locally advanced ASC patients benefiting from neoadjuvant ceritinib treatment with a tolerable safety profile, whereas further cohort studies of the efficacy and safety of neoadjuvant ceritinib in such patients are needed.

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

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

SIGNIFICANCE

This study confirms the prognostic value of MRD detection in patients with NSCLC after definitive surgery, especially in those with longitudinal undetectable MRD, which might represent the potentially cured population regardless of stage and adjuvant therapy. Moreover, the risk of developing detectable MRD decreased stepwise after 18 months since landmark detection. This article is highlighted in the In This Issue feature, p. 1599.

Case Report: Partial Response Following Nivolumab Plus Docetaxel in a Patient With EGFR Exon 20 Deletion/Insertion (p.N771delinsGF) Mutant Lung Adenocarcinoma Transdifferentiated From Squamous Cell Carcinoma

The histological transformation from lung squamous cell carcinoma (LUSC) to lung adenocarcinoma (LUAD) and p. N771delinsGF mutations in EGFR exon 20 (ex20) are exceedingly rare in non–small cell lung carcinoma (NSCLC). EGFR ex20 mutations are insensitive to EGFR tyrosine kinase inhibitors in NSCLC. Here, we present a 76-year-old male smoker harboring LUAD with a novel p. N771delinsGF deletion/insertion mutation in EGFR ex20 transdifferentiating from advanced LUSC after chemoradiotherapy. The patient presented reduced hydrothorax and relieved tightness with the treatment of nivolumab plus docetaxel and carboplatin after the failure of second-line chemotherapy. The case highlights the importance of rebiopsy and molecular retesting after the progression of lung cancer and supports the idea that the combination of immune checkpoint blockade and chemotherapy may be an attractive option for patients with EGFR ex20 mutations associated with LUSC–LUAD transformation.

Case Report: Detection of Double ROS1 Translocations, SDC4-ROS1 and ROS1-GK, in a Lung Adenocarcinoma Patient and Response to Crizotinib

ROS1 rearrangement, identified in ~2% of non-small cell lung cancer (NSCLC), has defined a distinctive molecular subtype. Patients with ROS1 fusion have been shown to be highly sensitive to treatment with crizotinib. However, the efficacy of crizotinib in NSCLC patients with double ROS1 fusions remains to be elucidated. Here, we report a 40-year-old male diagnosed with stage IIIA lung adenocarcinoma. Two ROS1 fusions [SDC4-ROS1 (EX2:EX32) and ROS1-GK (EX31:EX13)] were detected simultaneously in tumor tissue of this patient by next-generation sequencing. Crizotinib was administered, and the patient showed a partial response in lung lesions. Nevertheless, a brain lesion was found at 8 months after treatment. The slightly short duration of response may be related to the presence of ROS1-GK rearrangement. This case proved that patients with SDC4-ROS1 and ROS1-GK fusions may be sensitive to crizotinib, but short progression-free survival of this case showed that the presence of ROS1-GK rearrangement may affect the efficacy of crizotinib. A large-scale investigation on the efficacy of ROS1 inhibitors in patients with complex ROS1 fusions should be conducted in the future.

EGFR-Mutated Squamous Cell Lung Cancer and Its Association With Outcomes

Background

The therapeutic efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in advanced EGFR-mutant lung squamous cell carcinoma (SCC) patients remains uncertain. Furthermore, the factors underlying the responsiveness have not been fully investigated. We therefore investigated the link between genomic profiles and EGFR-TKI efficacy.

Material and Methods

We consecutively enrolled stage IV, EGFR-mutant, and EGFR-TKI–treated patients with SCC. Patients with EGFR wild-type lung SCC and EGFR-mutant lung adenocarcinoma were consecutively enrolled as controls, and next-generation sequencing (NGS) was performed.

Results

In total, 28 EGFR-mutant lung SCC, 41 EGFR-mutant lung adenocarcinoma, and 40 EGFR wild-type lung SCC patients were included. Among the patients with EGFR mutations, shorter progression-free survival (PFS) was observed in SCC compared to adenocarcinoma (4.6 vs. 11.0 months, P<0.001). Comparison of the genomic profiles revealed that EGFR-mutant SCC patients had similar mutation characteristics to EGFR-mutant adenocarcinoma patients, but differed from those with EGFR wild-type SCC. Further exploration of EGFR-mutant SCC revealed that mutations in CREBBP (P = 0.005), ZNF217 (P = 0.016), and the Wnt (P = 0.027) pathway were negatively associated with PFS. Mutations in GRM8 (P = 0.025) were associated with improved PFS.

Conclusions

EGFR-mutant lung SCC has a worse prognosis than EGFR-mutant adenocarcinoma. Mutations in other genes, such as CREBBP, ZNF217, GRM8, or Wnt that had implications on PFS raise the possibility of understanding mechanisms of resistance to EGFR-TKI in lung SCC, which will aid identification of potential beneficial subgroups of patients with EGFR-mutant SCCs receiving EGFR-TKIs.

Molecular biomarker testing for non-small cell lung cancer: consensus statement of the Korean Cardiopulmonary Pathology Study Group

Molecular biomarker testing is the standard of care for non–small cell lung cancer (NSCLC) patients. In 2017, the Korean Cardiopulmonary Pathology Study Group and the Korean Molecular Pathology Study Group co-published a molecular testing guideline which contained almost all known genetic changes that aid in treatment decisions or predict prognosis in patients with NSCLC. Since then there have been significant changes in targeted therapies as well as molecular testing including newly approved targeted drugs and liquid biopsy. In order to reflect these changes, the Korean Cardiopulmonary Pathology Study Group developed a consensus statement on molecular biomarker testing. This consensus statement was crafted to provide guidance on what genes should be tested, as well as methodology, samples, patient selection, reporting and quality control.

Immune subgroup analysis for non-small cell lung cancer may be a good choice for evaluating therapeutic efficacy and prognosis

Due to its effectiveness, cancer immunotherapy has attracted widespread attention from clinicians and scientific researchers. Numerous studies have proven that effective stratification of cancer patients would promote the personalized application of immunotherapy. Therefore, we used the transcriptome data of nearly 1,000 patients with non-small cell lung cancer (NSCLC) to construct a new immune subgroup. We found that the new immune subgroup, named cluster 2, was a mixture of lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), and showed poor overall survival, which was further verified in the independent validation set. Immune infiltration correlation analysis showed that the Mast cell type and its status subdivisions had a predictive effect on the prognosis of NSCLC, especially in LUAD. Phenotypic analysis suggested that epithelial-mesenchymal transition (EMT) was positively correlated with immunosuppression, supporting the correlation between tumor phenotype and immune background. Although immune subtypes failed to significantly distinguish the progression-free survival (PFS) of immunotherapy patients, they showed the expected trend; the sample size needs to be further expanded for verification. In addition, some results indicated that the two cancer types, LUAD and LUSC, might require independent analyses.

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

The poor prognosis and fewer treatment option is a current clinical challenge for patients with lung adenosquamous carcinoma (ASC). The previous studies reported that tumor mutational burden (TMB, numbers of mutation per Megabase) is a predictor of clinical response in trials of multiple cancer types, while fewer studies assessed the relationship between TMB level and clinical features and outcomes of lung ASC. Herein, the present study enrolled Chinese patients with lung ASC. DNA was extracted from formalin-fixed paraffin-embedded tumor samples and subjected to next generation sequencing (NGS), and the 457 cancer related genes were evaluated. The results demonstrated that 95 unique genes with somatic variations were identified in the enrolled patients. The top three of high frequency gene mutations were TP53, EGFR, PIK3CA with rates of 62% (13 cases), 48% (10 cases), and 14% (3 cases), respectively. We identified TMB value was significantly correlated with pathological stages (p < 0.05) and invasion of lymph node (p < 0.05). However, TMB value was not significantly correlated to other clinicopathologic indexes, for examples, age, sex, smoking history, tumor size, as well as TP53 and EGFR mutations in lung ASC. Moreover, TMB value was associated with the overall survival (p < 0.01), but not with the relapse-free survival (p = 0.23). In conclusion, this study indicated that lung ASC with high TMB might be associated with the invasion of lymph node and short overall survival. Immunotherapy might be a promising treatment option for lung ASC patients with high TMB.

Genomic origin and intratumor heterogeneity revealed by sequencing on carcinomatous and sarcomatous components of pulmonary sarcomatoid carcinoma

Pulmonary sarcomatoid carcinoma (PSC) contains carcinomatous component (CaC) and sarcomatous component (SaC). Herein, we explored the genomic origin and intratumor heterogeneity (ITH) of PSC. We collected 31 resected PSC tumors and obtained CaC and SaC by laser capture microdissection for next-generation sequencing. The majority of PSCs (97%) had component-shared alterations. Driver mutations in EGFR, KRAS, MET, PIK3CA, and EML4-ALK fusion were mostly component-shared. Twenty-seven (87%) PSCs had component-private alterations. Compared with pure lung adenocarcinoma (LUAD), adenocarcinoma component of PSC showed lower EGFR incidence. Compared with other typical sarcomas, numerous genes of SaC exhibited significant differences. CaC and SaC had equivalent and proportional tumor mutation burden (TMB), as well as PD-L1 level. Compared with LUAD, SaC had significant higher TMB and more patients with high PD-L1 expression (tumor proportion score ≥50%). PSC with lower proportion of component-shared alterations (trunk-ratio) had a prolonged disease-free survival (DFS), regardless of the influence of clinical factors. We conclude that most PSCs originate from a monoclone accompanied by genomic ITH which is a potential independent prognostic factor, and more proportion of PSCs may be beneficial from immune checkpoint inhibitors.

Genetic heterogeneity and predictive biomarker for pulmonary sarcomatoid carcinomas

PURPOSE

The aim of this study is to investigate the genetic heterogeneity (carcinomatous vs. sarcomatous components) and predictive biomarkers in patients with pulmonary sarcomatoid carcinoma (PSC).

METHODS

Genetic alterations and biomarkers of immunotherapy were performed in a discovery set (n = 6) of PSC. Next-generation sequencing (NGS) on a pan-cancer gene panel was applied to detect the genetic alterations in each component, and the respective mutation profiling and tumor mutation burden (TMB) were compared as well. Immunohistochemistry (IHC) assay with SP263 antibody was used to detect the protein expression of programmed death-ligand 1 (PD-L1) in each component.

RESULTS

Comparative genetic analysis revealed that the separate carcinomatous and sarcomatous components shared strikingly common mutations. TP53 (4/6, 66.7%) was the most common genetic alteration in 6 PSC patients. MET exon 14 skipping was detected in one case, accounting for 16.7%. An EZR-ROS1 fusion (EZR: intron10-ROS1: intron32) was identified in one case. The TMB of the two components was similar. Nevertheless, significantly higher PD-L1 expression was found in carcinomatous components compared to sarcomatous components. MDM2 amplification was detected in 2/6 (33.3%) of cases and STK11 mutation in 1/6 (16.7%) of cases.

CONCLUSIONS

PSC containing carcinomatous and sarcomatous components had a mild heterogeneity; the two components may evolve from common ancestral cells. High PD-L1 expression suggests that immunotherapy could be used as a potential therapy for PSC patients, while patients with negative immune-responsive genes need to be screened out. Altogether, these findings further highlight that the detection of genetic alteration and PD-L1 expression plays an important role in treatment of patients with PSC.

Deciphering the clonal relationship between glandular and squamous components in adenosquamous carcinoma of the lung using whole exome sequencing

Adenosquamous carcinoma of the lung (ASC) is a rare subtype of non-small cell lung cancer, consisting of lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) components. ASC shows morphological characteristics of classic LUAD and LUSC but behaves more aggressively. Although ASC can serve as a model of lung cancer heterogeneity and transdifferentiation, its genomic background remains poorly understood. In this study, we sought to explore the genomic landscape of macrodissected LUAD and LUSC components of three ASC using whole exome sequencing (WES). Identified truncal mutations included the pan-cancer tumor-suppressor gene TP53 but also EGFR, BRAF, and MET, which are characteristic for LUAD but uncommon in LUSC. No truncal mutation of classical LUSC driver mutations were found. Both components showed unique driver mutations that did not overlap between the three ASC. Mutational signatures of truncal mutations differed from those of the branch mutations in their descendants LUAD and LUSC. Most common signatures were related to aging (1, 5) and smoking (4). Truncal chromosomal copy number aberrations shared by all three ASC included losses of 3p, 15q and 19p, and an amplified region in 5p. Furthermore, we detected loss of STK11 and SOX2 amplification in ASC, which has previously been shown to drive transdifferentiation from LUAD to LUSC in preclinical mouse models. Conclusively, this is the first study using WES to elucidate the clonal evolution of ASC. It provides strong evidence that the LUAD and LUSC components of ASC share a common origin and that the LUAD component appears to transform to LUSC.

Adenocarcinomatous-predominant subtype associated with a better prognosis in adenosquamous lung carcinoma

Background

According to the proportion of glandular and squamous pathological components, adenosquamous carcinoma (ASC) could be divided into adenocarcinoma (AC) and squamous cell carcinoma (SCC) predominant subtypes. Due to its rarity, no study investigating the impact of different subtypes on the clinical features, radiologic findings and prognosis characteristics of ASC has been reported.

Methods

Sixty eight patients who underwent surgical resection for lung adenosquamous carcinoma in our institute between January 2006 and March 2017 were retrospectively reviewed. Data regarding the clinical features, radiologic findings and prognosis characteristics were collected.

Results

Thirty nine patients of the study cohort were with AC-predominant ASC and 29 with SCC-predominant ASC. There was no significant difference between the two subgroups in age, gender, smoking history, serum carcinoembryonic antigen (CEA) level and T,N classification. Air bronchogram was found more frequently in AC-predominant ASC than in SCC-predominant ASC (P = 0.046). Multivariate analysis identified pathological subtype (P = 0.022) and CT findings of peripheral location (P = 0.009) to be independent prognostic factors.

Conclusions

AC-predominant ASC were more commonly presented with air bronchogram, and were with a better prognosis than SCC-predominant ASC.