Comparison of Clinicopathological Features and Prognosis between ALK Rearrangements and EGFR Mutations in Surgically Resected Early-stage Lung Adenocarcinoma

Prognostic implications, genomic and immune characteristics of lung adenocarcinoma with lepidic growth pattern

AIMS

Conflicting data were provided regarding the prognostic impact and genomic features of lung adenocarcinoma (LUAD) with lepidic growth pattern (LP+A). Delineation of the genomic and immune characteristics of LP+A could provide deeper insights into its prognostic implications and treatment determination.

METHODS

We conducted a search of articles in PubMed, EMBASE and the Cochrane Library from inception to January 2024. A domestic cohort consisting of 52 LUAD samples was subjected to whole-exome sequencing as internal validation. Data from The Cancer Genomic Atlas and the Gene Expression Omnibus datasets were obtained to characterise the genomic and immune profiles of LP+A. Pooled HRs and rates were calculated.

RESULTS

The pooled results indicated that lepidic growth pattern was either predominant (0.35, 95% CI 0.22 to 0.56, p<0.01) or minor (HR 0.50, 95% CI 0.36 to 0.70, p<0.01) histological subtype was associated with favourable disease-free survival. Pooled gene mutation rates suggested higher EGFR mutation (0.55, 95% CI 0.46 to 0.64, p<0.01) and lower KRAS mutation (0.14, 95% CI 0.02 to 0.25, p=0.02) in lepidic-predominant LUAD. Lepidic-predominant LUAD had lower tumour mutation burden and pooled positive rate of PD-L1 expression compared with other subtypes. LP+A was characterised by abundance in resting CD4+memory T cells, monocytes and γδ T cells, as well as scarcity of cancer-associated fibroblasts.

CONCLUSIONS

LP+A was a unique histological subtype with a higher EGFR mutation rate, lower tumour mutation burden and immune checkpoint expression levels. Our findings suggested potential benefits from targeted therapy over immunotherapy in LP+A.

Gene mutation, clinical characteristics and pathology in resectable lung adenocarcinoma

OBJECTIVE

With the wide use of CT scan in clinical practice, more lung cancer was diagnosed in resectable stage. Pathological examination and genetic testing have become a routine procedure for lung adenocarcinoma following radical resection. This study analyzed special pathological components and gene mutations to explore their relationship with clinical characteristics and overall survival.

METHODS

Clinical, pathological, and gene mutation data from 1,118 patients were collected. All patients underwent surgery at the Department of Thoracic Surgery, the Second Xiangya Hospital of Central South University. Patients were grouped based on pathological components and gene mutations. Differences in clinical features and overall survival were analyzed as well.

RESULTS

Patients with mucinous, neuroendocrine, and poor-differentiated components were presented with more prognostic risk factors, including pleural invasion, carcinothrombosis, STAS, and advanced stages, along with varying frequencies of gene mutations. These factors significantly shortened overall survival. ALK and KRAS mutations were also associated with risk factors such as solid nodules, pleural invasion, STAS, and later stages. However, a significant reduction in overall survival was observed only in patients with the KRAS mutation. Relationship between gene mutations and pathological components still requires further investigation.

CONCLUSION

Special pathological components (mucinous, neuroendocrine, and poor-differentiated) and gene mutations had an influence on biological behavior of tumors, resulting in different clinical characteristics and prognosis.

Risk Stratification and Adjuvant Chemotherapy for High-Risk Stage IA Lung Adenocarcinoma: The Unmet Needs

INTRODUCTION

To identify high-risk patients for recurrence in resected stage IA lung adenocarcinoma and evaluate the impact of adjuvant chemotherapy (ACT) on their prognosis, as well as explore potential novel adjuvant therapies.

METHODS

Consecutive stage IA patients with ≥ 5% solid or micropapillary subtypes were analyzed. A nomogram was developed using Cox proportional hazards regression to predict recurrence-free survival (RFS). In the high-risk group after stratification, RFS was compared between patients receiving ACT and those under observation, as well as between patients with and without driver gene alterations.

RESULTS

This real-world study included 1328 patients, with a 5-year RFS of 79.0%. T stage and predominant subtype were independent risk factors for RFS. Patients with T1c or solid/micropapillary-predominant tumors were stratified into a high-risk group (n = 483) using the nomogram. A significant difference in 5-year RFS was observed between the high- and low-risk groups (73.6% vs. 84.3%, p < 0.001). Among high-risk patients, sixty-seven (13.8%) received ACT; however, there was no improvement in 5-year RFS compared to observation alone (69.1% vs. 75.0%, p = 0.655). Testing rates for EGFR mutation and ALK fusion among high-risk patients were only 52.4% and 43.9%, respectively, while mutation rates reached up to 55.7% and 9.4%, respectively. These molecular alterations exhibited numerically worse 5-year RFS compared to wild-type (EGFR mutation, 70.6% vs. 87.8%, p = 0.108; ALK fusion, 66.3% vs. 73.6%, p = 0.404), though not significant.

CONCLUSIONS

ACT failed to meet the needs of stage IA patients with histological high-risk features. Further exploration of effective adjuvant target therapies is warranted for this patient subgroup.

Spatial whole exome sequencing reveals the genetic features of highly-aggressive components in lung adenocarcinoma

In invasive lung adenocarcinoma (LUAD), patients with micropapillary (MIP) or solid (SOL) components had a significantly poorer prognosis than those with only lepidic (LEP), acinar (ACI) or papillary (PAP) components. It is interesting to explore the genetic features of different histologic subtypes, especially the highly aggressive components. Based on a cohort of 5,933 patients, this study observed that in different tumor size groups, LUAD with MIP/SOL components showed a different prevalence, and patients with ALK alteration or TP53 mutations had a higher probability of developing MIP/SOL components. To control individual differences, this research used spatial whole-exome sequencing (WES) via laser-capture microdissection of five patients harboring these five coexistent components and identified genetic features among different histologic components of the same tumor. In tracing the evolution of components, we found that titin (TTN) mutation might serve as a crucial intratumor potential driver for MIP/SOL components, which was validated by a cohort of 146 LUAD patients undergoing bulk WES. Functional analysis revealed that TTN mutations enriched the complement and coagulation cascades, which correlated with the pathway of cell adhesion, migration, and proliferation. Collectively, the histologic subtypes of invasive LUAD were genetically different, and certain trunk genotypes might synergize with branching TTN mutation to develop highly aggressive components.

A validated model to predict spread through air space in lung adenocarcinoma

Background

Spread through air space (STAS) is currently considered to be a significant predictor of a poor outcome of pulmonary adenocarcinoma. Preoperative prediction of STAS is of great importance for treatment planning. The aim of the present study was to establish a nomogram based on computed tomography (CT) features for predicting STAS in lung adenocarcinoma and to assess the prognosis of the patients with STAS.

Methods

A retrospective cohort study was performed in Wuhan Union Hospital from December 2015 to March 2021. The sample was divided into training and testing cohorts. Clinicopathologic and radiologic variables were recorded. The independent risk factors for STAS were determined by stepwise regression and then incorporated into the nomogram. Receiver operating characteristic (ROC) curves and calibration curves analysed by the Hosmer-Lemeshow test were used to evaluate the performance of the model. Decision curve analysis (DCA) was conducted to determine the clinical value of the nomogram. The Kaplan-Meier method was used for survival analysis and the multivariable Cox proportional hazards regression model was used to identify independent predictors for recurrence-free survival (RFS) and overall survival (OS).

Results

The sample included 244 patients who underwent surgical resection for primary lung adenocarcinoma. The training cohort included 199 patients (68 STAS-positive and 131 STAS-negative patients), and the testing cohort included 45 patients (15 STAS-positive and 30 STAS-negative patients). The preoperative CT features associated with STAS were shape, ground-glass opacity (GGO) ratio and spicules. The nomogram including these three factors had good discriminative power, and the areas under the ROC curve were 0.875 and 0.922 for the training and testing data sets, respectively, with well-fitted calibration curves. DCA showed that the nomogram was clinically useful. STAS-positive patients had significantly worse OS and RFS than STAS-negative patients (both P<0.01). OS and RFS at 5-year for STAS-positive patients were 63.1% and 59.5%, respectively. Multivariate analysis showed that age [hazard ratio (HR), 1.1; 95% confidence interval (CI): 1.035-1.169; P=0.002], diameter (HR, 1.06; 95% CI: 1.04-1.11; P=0.03) and surgical margin (HR, 32.8; 95% CI: 6.8-158.3; P<0.001) were independent risk factors for OS. Adjuvant therapy (HR, 7.345; 95% CI: 2.52-21.41; P<0.001), N stage (N2) (HR, 0.239; 95% CI: 0.069-0.828; P=0.02) and surgical margin (HR, 15.6; 95% CI: 5.9-41.1; P<0.001) were found to be independent risk factors for RFS.

Conclusions

The outcome of STAS-positive patients was worse. The nomogram incorporating the identified CT features could be applied to facilitate individualized preoperative prediction of STAS and selection of rational therapy.

An eleven-gene risk model associated with lymph node metastasis predicts overall survival in lung adenocarcinoma

Lung adenocarcinoma (LUAD) occupies major causes of tumor death. Identifying potential prognostic risk genes is crucial to predict the overall survival of patients with LUAD. In this study, we constructed and proved an 11-gene risk signature. This prognostic signature divided LUAD patients into low- and high-risk groups. The model outperformed in prognostic accuracy at varying follow-up times (AUC for 3 years: 0.699, 5 years: 0.713, and 7 years: 0.716). Two GEO datasets also indicate the great accuracy of the risk signature (AUC = 782 and 771, respectively). Multivariate analysis identified 4 independent risk factors including stage N (HR 1.320, 95% CI 1.102-1.581, P = 0.003), stage T (HR 3.159, 95% CI 1.920-3.959, P < 0.001), tumor status (HR 5.688, 95% CI 3.883-8.334, P < 0.001), and the 11-gene risk model (HR 2.823, 95% CI 1.928-4.133, P < 0.001). The performance of the nomogram was good in the TCGA database (AUC = 0.806, 0.798, and 0.818 for 3-, 5- and 7-year survival). The subgroup analysis in different age, gender, tumor status, clinical stage, and recurrence stratifications indicated that the accuracy was high in different subgroups (all P < 0.05). Briefly, our work established an 11-gene risk model and a nomogram merging the model with clinicopathological characteristics to facilitate individual prediction of LUAD patients for clinicians.

EGFR T751_I759delinsN Mutation in Exon19 Detected by NGS but Not by Real-Time PCR in a Heavily-Treated Patient with NSCLC

The detection of driver gene mutations can determine appropriate treatment strategies for non-small cell lung cancer (NSCLC) by identifying the presence of an effective druggable target. Mutations in the gene encoding the epidermal growth factor receptor (EGFR) are common driver mutations in NSCLC that can be effectively targeted by the use of EGFR tyrosine kinase inhibitors (EGFR-TKIs). However, without the detection of driver mutations, appropriate therapeutic decisions cannot be made. The most commonly applied methods for detecting driver gene mutations are assays based on polymerase chain reaction (PCR). However, the underlying mechanism of PCR-based assays limits the detection of rare mutations. Therefore, patients harboring rare mutations may not receive optimal treatment. We report a heavily-treated patient with NSCLC who harbored a T751_I759delinsN mutation in exon 19 of EGFR that was not detected by real-time PCR but was successfully detected by next-generation sequencing (NGS). The detection of a driver mutation using NGS resulted in the administration of targeted therapy, leading to favorable progression-free survival for the patient. Our report highlights the importance and potential of routine NGS testing among NSCLC patients for whom traditional assays fail to detect driver mutations when determining treatment options.

[Consensus on Postoperative Recurrence Prediction of Non-small Cell Lung Cancer Based on Molecular Markers]

Significant progress has been made in lung cancer screening, surgery, chemoradiation, targeted therapy, and immunotherapy recently. Surgical resection is the most important treatment for localized non-small cell lung cancer (NSCLC) so far, but there are still many patients who develop local recurrence or distant metastases within 5 years of surgery. Currently, the risk factors of recurrence in patients with NSCLC are mainly based on clinical and pathological features, which hardly identify patients at high risk of recurrence accurately. With the development of new detection technologies, a number of molecular markers that may have a predictive risk of recurrence in NSCLC have been discovered over the years. In order to summarize the molecular markers related to postoperative recurrence in NSCLC patients, we have formulated a consensus on the prediction of postoperative recurrence of NSCLC based on molecular markers. This consensus mainly focuses on the early stage NSCLC patients, discusses and summarizes the risk factors of disease recurrence from the molecular level. It is hoped that more and more valuable information can be provided for the management of patients, so as to provide more guidance for the perioperative management of the patients with early stage NSCLC in the future.
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[Relationship between EGFR, ALK Gene Mutation and Imaging and Pathological Features in Invasive Lung Adenocarcinoma]

BACKGROUND

At present, the research progress of targeted therapy for epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) gene mutations in lung adenocarcinoma is very rapid, which brings new hope for the treatment of advanced lung adenocarcinoma patients. However, the specific imaging and pathological features of EGFR and ALK gene mutations in adenocarcinoma are still controversial. This study will further explore the correlation between EGFR, ALK gene mutations and imaging and pathological features in invasive lung adenocarcinoma.

METHODS

A total of 525 patients with lung adenocarcinoma who underwent surgery in our center from January 2018 to December 2019 were included. According to the results of postoperative gene detection, the patients were divided into EGFR gene mutation group, ALK gene mutation group and wild group, and the EGFR gene mutation group was divided into exon 19 and exon 21 subtypes. The pathological features of the mutation group and wild group, such as histological subtype, lymph node metastasis, visceral pleural invasion (VPI) and imaging features such as tumor diameter, consolidation tumor ratio (CTR), lobulation sign, spiculation sign, pleural retraction sign, air bronchus sign and vacuole sign were analyzed by univariate analysis and multivariate Logistic regression analysis to explore whether the gene mutation group had specific manifestations.

RESULTS

EGFR gene mutation group was common in women (OR=2.041, P=0.001), with more pleural traction sign (OR=1.506, P=0.042), and had little correlation with lymph node metastasis and VPI (P>0.05). Among them, exon 21 subtype was more common in older (OR=1.022, P=0.036), women (OR=2.010, P=0.007), and was associated with larger tumor diameter (OR=1.360, P=0.039) and pleural traction sign (OR=1.754, P=0.029). Exon 19 subtype was common in women (OR=2.230, P=0.009), with a high proportion of solid components (OR=1.589, P=0.047) and more lobulation sign (OR=2.762, P=0.026). ALK gene mutations were likely to occur in younger patients (OR=2.950, P=0.045), with somking history (OR=1.070, P=0.002), and there were more micropapillary components (OR=4.184, P=0.019) and VPI (OR=2.986, P=0.034) in pathology.

CONCLUSIONS

The EGFR and ALK genes mutated adenocarcinomas have specific imaging and clinicopathological features, and the mutations in exon 19 or exon 21 subtype have different imaging features, which is of great significance in guiding the clinical diagnosis and treatment of pulmonary nodules.

Molecular typing of lung adenocarcinoma with computed tomography and CT image-based radiomics: a narrative review of research progress and prospects

Objective

The purpose of this paper was to perform a narrative review of current research evidence on conventional computed tomography (CT) imaging features and CT image-based radiomic features for predicting gene mutations in lung adenocarcinoma and discuss how to translate the research findings to guide future practice.

Background

Lung cancer, especially lung adenocarcinoma, is the leading cause of cancer-related deaths. With advances in the diagnosis and treatment of lung adenocarcinoma with the emergence of molecular testing, the prediction of oncogenes and even drug resistance gene mutations have become key to individualized and precise clinical treatment in order to prolong survival and improve quality of life. The progress of imageological examination includes the development of CT and radiomics are promising quantitative methods for predicting different gene mutations in lung adenocarcinoma, especially common mutations, such as epidermal growth factor receptor (EGFR) mutation, anaplastic lymphoma kinase (ALK) mutation and Kirsten rat sarcoma viral oncogene (KRAS) mutation.

Methods

The PubMed electronic database was searched along with a set of terms specific to lung adenocarcinoma, radiomics (including texture analysis), CT, computed tomography, EGFR, ALK, KRAS, rearranging transfection (RET) rearrangement and c-ros oncogene 1 (ROS-1), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), and human epidermal growth factor receptor 2 (HER2) mutations et al. This review has been reported in compliance with the Narrative Review checklist guidelines. From each full-text article, information was extracted regarding a set of terms above.

Conclusions

Research on the application of conventional CT features and CT image-based radiomic features for predicting the gene mutation status of lung adenocarcinoma is still in a preliminary stage. Noninvasively determination of mutation status in lung adenocarcinoma before targeted therapy with conventional CT features and CT image-based radiomic features remains both hopes and challenges. Before radiomics could be applied in clinical practice, more work needs to be done.

Clinicopathologic Features and Molecular Biomarkers as Predictors of Epidermal Growth Factor Receptor Gene Mutation in Non-Small Cell Lung Cancer Patients

Lung cancer ranks first in the incidence and mortality of cancer in the world, of which more than 80% are non-small cell lung cancer (NSCLC). The majority of NSCLC patients are in stage IIIB~IV when they are admitted to hospital and have no opportunity for surgery. Compared with traditional chemotherapy, specific targeted therapy has a higher selectivity and fewer adverse reactions, providing a new treatment direction for advanced NSCLC patients. Tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR-TKIs) are the widely used targeted therapy for NSCLC patients. Their efficacy and prognosis are closely related to the mutation status of the EGFR gene. Clinically, detecting EGFR gene mutation is often limited by difficulty obtaining tissue specimens, limited detecting technology, and economic conditions, so it is of great clinical significance to find indicators to predict EGFR gene mutation status. Clinicopathological characteristics, tumor markers, liquid biopsy, and other predictors are less invasive, economical, and easier to obtain. They can be monitored in real-time, which is supposed to predict EGFR mutation status and provide guidance for the accurate, individualized diagnosis and therapy of NSCLC patients. This article reviewed the correlation between the clinical indicators and EGFR gene mutation status in NSCLC patients.

Comparative Efficacy of Systemic Agents for Brain Metastases From Non-Small-Cell Lung Cancer With an EGFR Mutation/ALK Rearrangement: A Systematic Review and Network Meta-Analysis

BACKGROUND

Brain metastases (BM) from non-small-cell lung cancer (NSCLC) are frequent and carry significant morbidity, and current management options include varying local and systemic therapies. Here, we performed a systematic review and network meta-analysis to determine the ideal treatment regimen for NSCLC BMs with targetable EGFR-mutations/ALK-rearrangements.

METHODS

We searched MEDLINE, EMBASE, Web of Science, ClinicalTrials.gov, CENTRAL and references of key studies for randomized controlled trials (RCTs) published from inception until June 2020. Comparative RCTs including ≥10 patients were selected. We used a frequentist random-effects model for network meta-analysis (NMA) and assessed the certainty of evidence using the GRADE approach. Our primary outcome of interest was intracranial progression-free survival (iPFS).

RESULTS

We included 24 studies representing 19 trials with 1623 total patients. Targeted tyrosine kinase inhibitors (TKIs) significantly improved iPFS, with second-and third- generation TKIs showing the greatest benefit (HR=0.25, 95%CI 0.15-0.40). Overall PFS was also improved compared to conventional chemotherapy (HR=0.47, 95%CI 0.36-0.61). In EGFR-mutant patients, osimertinib showed the greatest benefit in iPFS (HR=0.32, 95%CI 0.15-0.69) compared to conventional chemotherapy, while gefitinib + chemotherapy showed the greatest overall PFS benefit (HR=0.26, 95%CI 0.10-0.70). All ALKi improved overall PFS compared to conventional chemotherapy, with alectinib having the greatest benefit (HR=0.13, 95%CI 0.07-0.24).

CONCLUSIONS

In patients with NSCLC BMs and EGFR/ALK mutations, targeted TKIs improve intracranial and overall PFS compared to conventional modalities such as chemotherapy, with greater efficacy seen using newer generations of TKIs. This data is important for treatment selection and patient counseling, and highlights areas for future RCT research.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=179060.

Perioperative ctDNA-based Molecular Residual Disease Detection for Non-Small Cell Lung Cancer: A Prospective Multicenter Cohort Study (LUNGCA-1)

PURPOSE

We assessed whether perioperative circulating tumor DNA (ctDNA) could be a biomarker for early detection of molecular residual disease (MRD) and prediction of postoperative relapse in resected non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Based on our prospective, multicenter cohort on dynamic monitoring of ctDNA in lung cancer surgery patients (LUNGCA), we enrolled 950 plasma samples obtained at three perioperative time points (before surgery, 3-day and 1-month after surgery) of 330 stage I-III NSCLC patients (LUNGCA-1), as a part of LUNGCA cohort. Using a customized 769-gene panel, somatic mutations in tumor tissues and plasma samples were identified with next-generation sequencing and utilized for ctDNA-based MRD analysis.

RESULTS

Preoperative ctDNA positivity was associated with lower recurrence-free survival (RFS) (HR=4.2; P<0.001). The presence of MRD (ctDNA positivity at postoperative 3-day and/or 1-month) was a strong predictor for disease relapse (HR=11.1; P<0.001). ctDNA-based MRD had a higher relative contribution to RFS prediction than all clinicopathological variables such as the TNM stage. Furthermore, MRD-positive patients who received adjuvant therapies had improved RFS over those not receiving adjuvant therapy (HR=0.3; P=0.008), whereas MRD-negative patients receiving adjuvant therapies had lower RFS than their counterparts without adjuvant therapy (HR=3.1; P<0.001). After adjusting for clinicopathological variables, whether receiving adjuvant therapies remained an independent factor for RFS in the MRD-positive population (P=0.002) but not in the MRD-negative population (P=0.283).

CONCLUSIONS

Perioperative ctDNA analysis is effective in early detection of MRD and relapse risk stratification of NSCLC, and hence could benefit NSCLC patient management.

Pleural invasion, epidermal growth factor receptor mutation and carcinoembryonic antigen level affect pleural lavage cytology-positive status in non-small-cell lung cancer

OBJECTIVES

Pleural invasion (pl) is strongly associated with the pleural lavage cytology (PLC) status. We analysed tumours with pl and evaluated the relationship between the PLC status and pl.

METHODS

We retrospectively reviewed 428 surgically treated patients who had been diagnosed with non-small-cell lung cancer with pl and had their PLC status examined between 2000 and 2016. We investigated the influence of a PLC-positive status on the prognosis and searched for the factors predictive of a PLC-positive status.

RESULTS

Seventy-eight (18%) patients were PLC positive. The recurrence-free survival of PLC-positive patients was significantly worse than that of PLC-negative patients in pl1 and pl2, but not in pl3 (5-year recurrence-free survival rate, PLC positive versus PLC negative: pl1, 22.0% vs 60.0%, P = 0.002; pl2, 30.4% vs 59.7%, P = 0.015; pl3, 50.0% vs 59.6%, P = 0.427). A multivariable analysis showed that the degree of pl (pl2-3 versus pl1) [odds ratio (OR) 5.34, P < 0.001] was an independent predictive factor for PLC positivity. Epidermal growth factor receptor (EGFR) mutation positivity (OR 5.48, P = 0.042) and carcinoembryonic antigen (CEA) ≥5 ng/ml (OR 3.78, P = 0.042) were associated with a PLC-positive status in patients with pl2-3. We found that the PLC-positive rate in patients with pl2-3 was 35.6%; however, if the tumour was EGFR mutation positive and had CEA ≥5 ng/ml, the PLC-positive rate increased to 77%.

CONCLUSIONS

If a tumour was suspected of being pl2-3 and had EGFR mutation positivity and CEA ≥5 ng/ml, the PLC-positive rate was extremely high.

CLINICAL TRIAL REGISTRATION NUMBER

Hyogo Cancer Center, G-138.

Assessment of relationships among clinicopathological characteristics, morphological computer tomography features, and tumor cell proliferation in stage I lung adenocarcinoma

Background

Surgically resected stage I lung adenocarcinoma (ADC) has wide variation in prognosis. It is significant to identify high-risk patients and optimize therapeutic strategy. This study aimed to investigate the relationships among histological grade, serum tumor marker index (TMI), morphological computer tomography (CT) features, and a well-established prognosticator cell proliferation (Ki-67) in stage I ADC.

Methods

Preoperative CT was performed in 182 patients with stage I ADC confirmed by pathology. The Ki-67 expression was acquired by immunohistochemistry. TMI was the square root of standardized serum carcinoembryonic antigen (CEA) and cytokeratin 19 fragments (CYFRA 21-1) values. Tumor shadow disappearance rate (TDR) and other morphological CT features were interpreted by two radiologists. Histological grade, TMI, CT features were statistically evaluated to explore the associations with Ki-67 expression.

Results

In univariate analysis, gender, smoking history, pack-year, histological grade, TNM stage (IA and IB), serum CEA and CYFRA 21-1 status, TMI status, as well as TDR, long-axis diameter, short-axis diameter, lobulation, spiculation, attenuation types, vacuolation, vascular invasion, vascular convergence, thickened bronchovascular bundles, pleural attachment and peripheral fibrosis were significantly associated with Ki-67 expression (all P<0.05). Solid-predominant ADC had the highest Ki-67 expression, followed by micropapillary, papillary and acinar-predominant ADC, while lepidic-predominant ADC had the lowest Ki-67 expression (P<0.001). TDR was negatively correlated with Ki-67 (r =−0.478, P<0.001). Multivariate logistic regression analysis revealed that gender, histological grade, TDR and attenuation types were independent factors associated with Ki-67 expression.

Conclusions

Ki-67 expression differed distinctly according to ADC histological subtypes. High Ki-67 expression is independently associated with male patients of stage I ADC with worse differentiation, lower TDR and solid tumors, which might be of prognostic value for poor prognosis in stage I ADC.

Four long noncoding RNAs act as biomarkers in lung adenocarcinoma

Introduction

Lung adenocarcinoma (LUAD) is currently one of the most common malignant tumors worldwide. However, there is a lack of long noncoding RNA (lncRNA)-based effective markers for predicting the prognosis of LUAD patients. We identified four lncRNAs that can effectively predict the prognosis of LUAD patients.

Methods

We used data gene expression profile for 446 patients from The Cancer Genome Atlas database. The patients were randomly divided into a training set and a test set. Significant lncRNAs were identified by univariate regression. Then, multivariate regression was used to identify lncRNAs significantly associated with the survival rate. We constructed four-lncRNA risk formulas for LUAD patients and divided patients into high-risk and low-risk groups. Identified lncRNAs subsequently verified in the test set, and the clinical independence of the lncRNA model was evaluated by stratified analysis. Then mutated genes were identified in the high-risk and low-risk groups. Enrichment analysis was used to determine the relationships between lncRNAs and co-expressed genes. Finally, the accuracy of the model was verified using external database.

Results

A four-lncRNA signature (AC018629.1, AC122134.1, AC119424.1, and AL138789.1) has been verified in the training and test sets to be significantly associated with the overall survival of LUAD patients.

Conclusions

The present study demonstrated that identified four-lncRNA signature can be used as an independent prognostic biomarker for the prediction of survival of LUAD patients.

Targeted Sequencing Analysis of Predominant Histological Subtypes in Resected Stage I Invasive Lung Adenocarcinoma

Objective: Lung adenocarcinoma (LADC) is classified into five main histological subtypes with distinct clinicopathologic characteristics: lepidic-predominant adenocarcinoma (LPA), acinar-predominant adenocarcinoma (APA), papillary-predominant adenocarcinoma (PPA), micropapillary-predominant adenocarcinoma (MPA) and solid-predominant adenocarcinoma (SPA). However, the mutational profiles of predominant histological subtypes have not been well defined. In this study, we aimed to reveal the genomic landscape of 5 main histological subtypes. Patients and Methods: We performed next-generation sequencing (NGS) in a cohort of 86 stage I invasive adenocarcinoma (IAC) patients, using a customized panel including 168 cancer-associated genes. Results: Our analysis identified a total of 302 genomic alterations. Five subtypes showed different mutation profiles with LPA, APA, PPA, MPA and SPA had an average mutation rate of 1.95 (range: 0-5), 2.56 (range: 1-6), 3.5 (range: 1-7), 3.75 (range: 1-8) and 6.05 (range: 2-12), respectively (p=4.17e-06). Driver mutations occurred in 96.55% (83/86) of all patients. EGFR (73.3%), KRAS (9.3%), ALK (4.7%) and MET (4.7%) are the most commonly mutated lung cancer driver genes, TP53 is the top mutated tumor suppressor gene. SPA patients harbored more driver mutations and higher frequency of TP53 than LPA patients. Interestingly, LRP1B mutations, which has been reported to be associated with high tumor mutation burden and better response to immunotherapy, were only detected from 5 SPA patients (p=0.001). No patients from other four cohorts harbored LRP1B mutations. Conclusions: We revealed distinctive mutation landscape of the 5 major histological subtypes of LADC, evident by distinctive average mutation rate with SPA and LPA having the highest and lowest average mutation rate, respectively. SPA patients showed higher mutation rate of LRP1B and higher rates for PD-L1 positivity, indicating that SPA patients may have better response to immunotherapy.

Value of CT features for predicting EGFR mutations and ALK positivity in patients with lung adenocarcinoma

The aim of this study was to identify the relationships of epidermal growth factor receptor (EGFR) mutations and anaplastic large-cell lymphoma kinase (ALK) status with CT characteristics in adenocarcinoma using the largest patient cohort to date. In this study, preoperative chest CT findings prior to treatment were retrospectively evaluated in 827 surgically resected lung adenocarcinomas. All patients were tested for EGFR mutations and ALK status. EGFR mutations were found in 489 (59.1%) patients, and ALK positivity was found in 57 (7.0%). By logistic regression, the most significant independent prognostic factors of EGFR effective mutations were female sex, nonsmoker status, GGO air bronchograms and pleural retraction. For EGFR mutation prediction, receiver operating characteristic (ROC) curves yielded areas under the curve (AUCs) of 0.682 and 0.758 for clinical only or combined CT features, respectively, with a significant difference (p < 0.001). Furthermore, the exon 21 mutation rate in GGO was significantly higher than the exon 19 mutation rate(p = 0.029). The most significant independent prognostic factors of ALK positivity were age, solid-predominant-subtype tumours, mucinous lung adenocarcinoma, solid tumours and no air bronchograms on CT. ROC curve analysis showed that for predicting ALK positivity, the use of clinical variables combined with CT features (AUC = 0.739) was superior to the use of clinical variables alone (AUC = 0.657), with a significant difference (p = 0.0082). The use of CT features for patients may allow analyses of tumours and more accurately predict patient populations who will benefit from therapies targeting treatment.

An intergenic region ALK fusion identified by DNA sequencing and validated by IHC in an early-stage lung adenocarcinoma

Anaplastic Lymphoma Kinase (ALK) fusion is an important driver mutation and therapeutic target. At present, more than 20 fusion partners for ALK in NSCLC have been reported. However, ALK intergenic-breakpoint fusions confound fusion detection and target treatment. Here, we reported a 53-year-old early-stage lung adenocarcinoma patient with an MIR548AD-ALK intergenic fusion and was verified by immunohistochemical staining (IHC). In early-stage NSCLC, compared with other clinically relevant driver mutations, ALK fusions were associated with a trend toward poor disease outcomes. Our Next-generation sequencing (NGS) and IHC results may indicate the prognosis of the patient and provide an alternative treatment option for postoperative recurrence.

A population-based study of outcomes in patients with surgically resected non-small cell lung cancer with anaplastic lymphoma kinase-rearranged mutations: A matched-pair study

The present study aimed to evaluate clinical outcomes in patients with surgically resected non-small cell lung cancer (NSCLC) with anaplastic lymphoma kinase (ALK)-rearranged mutations. A matched-pair analysis in completely resected ALK-rearranged NSLC patients and those with neither ALK nor epidermal growth factor receptor (EGFR) mutations diagnosed at 11 institutes was performed between April 2008 and March 2019. A total of 51 patients with surgically resected ALK-rearranged NSCLC were included. Women constituted 68.6%, and smokers 29.4%. The median age was 65 years. In matched-pair analysis, disease-free survival and overall survival did not differ between patients with ALK-rearranged mutations and those without mutations. Post-recurrence survival in patients with ALK mutations was longer than that of patients with neither ALK nor epidermal growth factor receptor mutations. ALK genetic testing should be performed, even in elderly patients with NSCLC. Favorable prognosis might be expected after appropriate treatment for patients with recurrent ALK-mutated disease.

Prognostic effects of the expression of inhibitor of DNA-binding family members on patients with lung adenocarcinoma

The basic helix-loop-helix (bHLH) transcription factors are negatively regulated by inhibitor of DNA-binding (ID) proteins. Several studies have demonstrated that ID family proteins are dysregulated in a variety of cancer types, including in lung adenocarcinoma (LUAD). In current study, the prognostic value of ID family members was evaluated by investigating publicly accessible databases, including Oncomine, Kaplan-Meier plotter, UALCAN and the Human Protein Atlas. It was observed that the mRNA expression of all ID members was downregulated in LUAD tumor tissues compared with those in normal tissues according to the Oncomine and UALCAN databases. Additionally, increased mRNA expression levels of ID2 and ID1 were associated with improved and poorer survival time, respectively. Notably, ID3 and ID4 expression was not associated with survival in patients with LUAD. At the protein level, high ID2 significantly predicted an improved survival outcome while high ID1 is associated with shorter survival time. Thus, the results indicate that the ID proteins, particularly ID2, exhibit significant prognostic value in LUAD. More studies are required to elucidate the underlying molecular mechanisms behind the role of the ID family in the development of LUAD.

Distribution of EML4-ALK fusion variants and clinical outcomes in patients with resected non-small cell lung cancer

OBJECTIVES

The molecular profiles and prognosis of anaplastic lymphoma kinase (ALK) fusion and resectable non-small cell lung cancer (NSCLC) remain unclear. This study aimed to explore the distribution of ALK fusion variants and prognostic factors in patients with surgically resected NSCLC.

MATERIAL AND METHODS

Among the 93 ALK positive surgical patients screened by immunohistochemistry (IHC) or real-time polymerase chain reaction (RT-PCR), 63 patients were confirmed as ALK rearrangement by next-generation sequencing (NGS), including 55 cases of stage I-III and 8 cases of stage IV. Medical records were retrospectively reviewed, the distribution of ALK fusion variants and prognostic factors were analyzed.

RESULTS

All of the 55 early stage patients were histological adenocarcinoma. No other fusion types were found except for echinoderm microtubule-associated protein-like 4- anaplastic lymphoma kinase (EML4-ALK). EML4-ALK variant 1 (E13:A20; 25/55, 45.5 %) was the predominant variant type, followed by EML4-ALK variant 3 (E6:A20; 19/55, 34.5 %) and variant 2 (E20:A20; 8/55, 14.5 %). Concomitant mutations occurred in 22 patients (22/55, 40.0 %), which involved in 32 co-mutations from 12 kinds of mutated genes. TP53 mutations were most common in coexisting mutations (13/32, 40.6 %). TP53 mutations were less frequently occurred in variant 1 group (3/25, 12.0 %) than in non-variant 1 group (10/30, 33.3 %, P = 0.064). The median disease-free survival (DFS) of the 55 patients was 22.1 months, and the median overall survival (OS) was not mature at the time of analysis. Multivariable analysis showed that stage T3 and EML4-ALK variant 3 were independent prognostic factors for shorter DFS. Neither TP53 mutations nor any coexisting mutations were related to prognosis.

CONCLUSIONS

This study illustrated the patterns of EML4-ALK fusion variants and gene profiles in patients with resected NSCLC. Advanced T stage and EML4-ALK variant 3 were associated with worse prognosis. The role of TP53 mutations in prognosis is worthy of further study.

CT features associated with EGFR mutations and ALK positivity in patients with multiple primary lung adenocarcinomas

Background

In multiple primary lung adenocarcinomas (MPLAs), the relationship between imaging and gene mutations remains unclear. This retrospective study aimed to identify the correlation of epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) status with CT characteristics in MPLA patients.

Methods

Sixty-seven patients (135 lesions) with MPLAs confirmed by pathology were selected from our institution. All subjects were tested for EGFR mutations and ALK status and underwent chest CT prior to any treatment. The criteria for MPLA definitions closely adhered to the comprehensive histologic assessment (CHA).

Results

Among MPLA patients, EGFR mutations were more common in females (p = 0.002), in those who had never smoked (p = 0.010), and in those with less lymph node metastasis (p < 0.001), and the tumours typically presented with ground-glass opacity (GGO) (p = 0.003), especially mixed GGO (p < 0.001), and with air bronchograms (p = 0.012). Logistics regression analysis showed that GGO (OR = 6.550, p = 0.010) was correlated with EGFR mutation, while air bronchograms were not correlated with EGFR mutation (OR = 3.527, p = 0.060). A receiver operating characteristic (ROC) curve yielded area under the curve (AUC) values of 0.647 and 0.712 for clinical-only or combined CT features, respectively, for prediction of EGFR mutations, and a significant difference was found between them (p = 0.0344). ALK-positive status was found most frequently in MPLA patients who were younger (p = 0.002) and had never smoked (p = 0.010). ALK positivity was associated with solid nodules or masses in MPLAs (p < 0.004) on CT scans. Logistics regression analysis showed that solid nodules (OR = 6.550, p = 0.010) were an independent factor predicting ALK positivity in MPLAs. For prediction of ALK positivity, the ROC curve yielded AUC values of 0.767 and 0.804 for clinical-only or combined CT features, respectively, but no significant difference was found between them (p = 0.2267).

Conclusion

Among MPLA patients, nonsmoking women with less lymph node metastasis and patients with lesions presenting GGO or mixed GGO and air bronchograms on CT were more likely to exhibit EGFR mutations. In nonsmoking patients, young patients with solid lesions on CT are recommended to undergo an ALK status test.

MUC5AC enhances tumor heterogeneity in lung adenocarcinoma with mucin production and is associated with poor prognosis

OBJECTIVE

The clinicopathological significance of Mucin5AC (MUC5AC) in lung adenocarcinoma with mucin production is still unclear. This study aimed to explore MUC5AC expression in lung adenocarcinoma with mucin production and its correlation with histological subtypes, common driver mutations and its impact on prognosis.

METHODS

MUC5AC and thyroid transcription factor 1 immunohistochemistry was performed on surgical samples from 90 patients with lung adenocarcinoma with mucin production. Common driver mutations including EGFR and KRAS mutations and ALK rearrangement were detected by established methods.

RESULTS

MUC5AC was significantly associated with lymphovascular invasion (P = 0.023) and tumors with intra-cytoplasmic mucin (P < 0.001). Moreover, MUC5AC was more significant in invasive mucinous adenocarcinoma (P < 0.001), as well as in tumors with KRAS mutations (P = 0.005) and a lack of thyroid transcription factor 1 expression (P < 0.001). Conversely, MUC5AC was less significantly detected in acinar predominant adenocarcinoma (P = 0.036) and tumors with EGFR mutations (P = 0.001). Notably, MUC5AC in non-pure mucinous subtype of lung adenocarcinoma with mucin production showed more aggressive behavior, distinct expression pattern and a lack of significant correlation with thyroid transcription factor 1 (P = 0.113) when compared with pure mucinous subtype. MUC5AC-positive tumors were significantly associated with a worse prognosis compared to MUC5AC-negative tumors (P < 0.001). A multivariate survival analysis showed that MUC5AC was an independent prognosis factor for poor prognosis (P = 0.006).

CONCLUSIONS

The clinicopathological features of non-pure mucinous subtype of lung adenocarcinoma with mucin production were distinct and should be distinguished from pure mucinous subtype. MUC5AC was associated with poor prognosis and could be a potential therapeutic target for this distinct type of lung adenocarcinoma that has few effective treatments.

Clinical, Conventional CT and Radiomic Feature-Based Machine Learning Models for Predicting ALK Rearrangement Status in Lung Adenocarcinoma Patients

Objectives: To predict the anaplastic lymphoma kinase (ALK) mutations in lung adenocarcinoma patients non-invasively with machine learning models that combine clinical, conventional CT and radiomic features.

Methods: This retrospective study included 335 lung adenocarcinoma patients who were randomly divided into a primary cohort (268 patients; 90 ALK-rearranged; and 178 ALK wild-type) and a test cohort (67 patients; 22 ALK-rearranged; and 45 ALK wild-type). One thousand two hundred and eighteen quantitative radiomic features were extracted from the semi-automatically delineated volume of interest (VOI) of the entire tumor using both the original and the pre-processed non-enhanced CT images. Twelve conventional CT features and seven clinical features were also collected. Normalized features were selected using a sequential of the F-test-based method, the density-based spatial clustering of applications with noise (DBSCAN) method, and the recursive feature elimination (RFE) method. Selected features were then used to build three predictive models (radiomic, radiological, and integrated models) for the ALK-rearranged phenotype by a soft voting classifier. Models were evaluated in the test cohort using the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity, and the performances of three models were compared using the DeLong test.

Results: Our results showed that the addition of clinical information and conventional CT features significantly enhanced the validation performance of the radiomic model in the primary cohort (AUC = 0.83–0.88, P = 0.01), but not in the test cohort (AUC = 0.80–0.88, P = 0.29). The majority of radiomic features associated with ALK mutations reflected information around and within the high-intensity voxels of lesions. The presence of the cavity and left lower lobe location were new imaging phenotypic patterns in association with ALK-rearranged tumors. Current smoking was strongly correlated with non-ALK-mutated lung adenocarcinoma.

Conclusions: Our study demonstrates that radiomics-derived machine learning models can potentially serve as a non-invasive tool to identify ALK mutation of lung adenocarcinoma.

Mucinous lung adenocarcinoma, particularly referring to EGFR-mutated mucinous adenocarcinoma

The current 2015 World Health Organization (WHO) classification of lung tumors does not adequately categorize mucinous lung adenocarcinoma. Thus far, only two variants of mucinous adenocarcinoma have been studied: invasive mucinous adenocarcinoma and colloid adenocarcinoma. Moreover, common types of invasive adenocarcinoma when they produce mucin are yet to be elucidated, particularly epidermal growth factor receptor (EGFR)-mutated mucinous adenocarcinoma. In this study, we extracted mucinous adenocarcinoma of both the common types and the two variants. Further, we immunohistochemically and molecular-biologically examined their clinicopathological characteristics, mutation patterns, and expressions of thyroid transcription factor-1 (TTF-1), hepatocyte nuclear factor-4 alpha (HNF-4a) and mucins, particularly referring to EGFR-mutated adenocarcinoma. Among 1159 surgically resected invasive adenocarcinomas, 189 mucinous adenocarcinomas (16%) were identified. Among these, 20%, 34% and 9.5% were EGFR mutated, KRAS mutated and ALK rearranged, respectively. Compared with EGFR-mutated nonmucinous adenocarcinoma, EGFR-mutated mucinous adenocarcinoma had no female predominance, lower grades of histological differentiation and lower TTF-1 and higher HNF-4a expressions. Moreover, for the first time, we indicated that mucin production was an independent prognostic factor for EGFR-mutated adenocarcinomas and the mucin-staining pattern of negative MUC5AC and positive MUC5B was characteristic in these adenocarcinomas. We suggest that EGFR-mutated mucinous adenocarcinoma has a different tumorigenic pathway than nonmucinous EGFR-mutated adenocarcinoma.

Expanding anaplastic lymphoma kinase therapeutic indication to early stage non-small cell lung cancer

Oncogene-addicted non-small cell lung cancer (NSCLC) patients have been witnessing overwhelming therapeutic improvements, especially in advanced disease management, due to the advent of more potent tyrosine kinase inhibitors (TKIs). However, the concrete chance to cure anaplastic lymphoma kinase (ALK)-rearranged patients remains prerogative of surgical and peri-operative medical approaches to early disease stage. Clinical investigations in the adjuvant setting of genotype-restricted lung cancers (i.e., EGFR+, ALK+, etc.) are under-represented owing to the need of large patients' enrollment and solid overall survival (OS) data, which solely can show real long-term impact of these therapeutic interventions. Current available radiological and molecular technologies will widely increase the number of surgical early stage patients, including ALK+, spurring the development of rational approaches aimed to prevent disease recurrence and prolong patients' survival. Ongoing clinical trials, evaluating crizotinib and alectinib as adjuvant treatments, will gauge the real impact of TKIs in terms of patients' disease free survival (DFS) and OS; other peri-operative investigations (e.g., neo-adjuvant strategies) will add information about ALK inhibitors' tumor growth restraint capacities and early adaptation mechanisms to ALK targeting. Nevertheless, multiple questions are and will remain unanswered: if should be treated indifferently all ALK+ patients or, alternatively, should be stratified in different risk groups based on the detectable residual disease [i.e., minimal residual disease (MRD) after surgery]; whether ALK inhibitors administration could facilitate the accumulations of persister cells driving resistance mechanisms to targeted therapies; if alternative strategies, as combined treatments targeting different molecular hubs, could enhance disease control and cancer eradication.

The incidence of lymph node metastasis in patients with different oncogenic driver mutations among T1 non-small-cell lung cancer

OBJECTIVE

To investigate the incidence and distribution of lymph node metastasis in patients with different gene mutations among pathological T1 non-small-cell lung cancers (NSCLC).

METHODS

NSCLC cases resected in our institution between 2016 and 2018 were included. Driver mutation testing was performed in all resected tumor tissues. These patients were grouped by the type of gene mutations. On the basis of protein that mutant-genes encoded involved in the molecular pathway, the genotypes were further classified into four distinct groups: upstream receptor mutant protein (EGFR, HER2 and MET); downstream regulator mutant protein (KRAS and BRAF); fusion mutant protein (ROS1, ALK and RET) and the wild type group. The incidence of lymph node metastasis was compared among different groups.

RESULTS

Of the 1052 patients enrolled, the frequency of positive mutations was 68.0%. The incidence of lymph node metastasis were as follows: wild type (19.3%), ROS1 (72.8%), BRAF (55.5%), ALK (44.7%), HER2 (40%), RET (23.1%), KRAS (15.3%), EGFR (15.3%) and MET mutation (0%) (P < 0.001). The incidence of lymph node metastasis was significantly higher in fusion mutant protein group (45.1%) compared with others (wild type 19.3%, downstream regulator mutant protein 19.1%, upstream receptor mutant protein 15.3%, all P < 0.001). Patients with fusion genes also showed higher proportion of vascular invasion and positive lymph node ratio of greater than 0.33 compared to others.

CONCLUSION

Different genotypes of NSCLC have different propensity to develop lymph node metastasis. Cases of fusion gene mutations had a higher risk and burden of lymph node metastasis than other genotypes, which may indicate that more intensive treatment or surveillance strategies should be applied for these patients.