Tumor-associated macrophage infiltration is associated with a higher rate of tumor spread through air spaces in resected lung adenocarcinomas

STAS: New explorations and challenges for thoracic surgeons

Spread through air spaces (STAS) represents a relatively novel concept in the pathology of lung cancer, and it specifically refers to the dissemination of tumour cells into the parenchymal air spaces adjacent to the primary tumour. In 2015, the World Health Organization (WHO) classified STAS as a new invasive form of lung adenocarcinoma (LUAD). Many studies investigated the role of STAS and revealed its association with the prognosis of LUAD and its influence on the outcomes of other malignant pulmonary neoplasms. Additionally, the underlying mechanisms and predictive models of STAS have received considerable attention in recent years. This paper provides a comprehensive overview of the research advancements and prospects of STAS by examining it from multiple perspectives.

Overexpression of VEGFA mediated by HIF-1 is associated with higher rate of spread through air spaces in resected lung adenocarcinomas

BACKGROUND

Spread through air spaces (STAS), a newly identified pattern of invasion in lung adenocarcinomas (LACs), is an unfavorable prognostic factor for patients with LAC, but the molecular characteristics and mechanisms underlying STAS have not been adequately explored.

METHODS

In total, 650 pathologically confirmed invasive LAC patients who underwent curative resection between December 2019 and April 2020 were reviewed. Disease-free survival (DFS) and overall survival (OS) were analyzed using the log-rank test and the Cox proportional hazards model. A comparative deep sequencing analysis was conducted to explore the molecular characteristics underlying STAS. Vascular endothelial growth factor A (VEGFA) expression was evaluated by immunoblotting and immunohistochemical analysis using fresh tumor tissue and tissue microarray.

RESULTS

STAS was more prevalent in patients with a smoking history (p < 0.001), high pathological TNM stage (p < 0.001), lymphovascular invasion (p < 0.001), visceral pleural invasion (p < 0.001) and micropapillary/solid histological subtypes (p < 0.001). STAS-negative patients had better DFS (p < 0.001) and OS (p = 0.003) compared to STAS-positive patients with invasive LACs, especially in the lymph node-negative population (p < 0.001). After RNA-sequencing analysis, hypoxia-inducible factor-1 (HIF-1) signaling was enriched and appeared to be strongly correlated with STAS, and more STAS-positive individuals were detected in the higher VEGFA-expressing group (p = 0.042).

CONCLUSIONS

We demonstrated that STAS was an independent prognostic marker of poor clinical outcome, especially in lymph node-negative patients, and that higher VEGFA expression mediated by HIF-1 signaling was associated with an increased STAS rate.

Cellular crosstalk of macrophages and therapeutic implications in non-small cell lung cancer revealed by integrative inference of single-cell transcriptomics

Introduction: Non-small cell lung cancer (NSCLC) exhibits heterogeneity with diverse immune cell infiltration patterns that can influence tumor cell behavior and immunotherapy. A comprehensive characterization of the tumor microenvironment can guide precision medicine. Methods: Here, we generated a single-cell atlas of 398170 cells from 52 NSCLC patients, and investigated the imprinted genes and cellular crosstalk for macrophages. Subsequently, we evaluated the effect of tumor cells on macrophages and verified the expression of marker genes using co-culture experiments, flow cytometry and RT-qPCR assays. Results: Remarkable macrophage adaptability to NSCLC environment was observed, which contributed to generating tumor-associated macrophages (TAMs). We identified 5 distinct functional TAM subtypes, of which the majority were SELENOP-positive macrophages, with high levels of SLC40A1 and CCL13. The TAMs were also involved in mediating CD8+ T cell activity and form intercellular interaction with cancer cells, as indicated by receptor-ligand binding. Indirect coculture of tumor cells SPC-A1 and THP-1 monocytes, produced M2-like TAMs that highly expressed several markers of SELENOP-positive macrophages. The abundance of this type TAMs seemed to be associated with poorer overall survival rates [hazard ratio (HR) = 1.34, 95% confidence interval (CI) = 0.98-1.83, p = 0.068] based on deconvolution of TCGA-LUAD dataset. Discussion: In summary, we provided a high-resolution molecular resource of TAMs, and displayed the acquired properties in the tumor microenvironment. Dynamic crosstalk between TAMs and tumor cells via multiple ligand-receptor pairs were revealed, emphasizing its role in sustaining the pro-tumoral microenvironment and its implications for cancer therapy.

Retrospective analysis of the prognostic implications of tumor spread through air spaces in lung adenocarcinoma patients treated with surgery

Background

Tumor spread through air spaces (STAS) in lung adenocarcinoma is a novel mechanism of invasion. STAS has been proposed as an independent predictor of poor prognosis. The aim of this study was to evaluate the correlations between STAS status and other clinicopathologic variables and to assess the prognostic implications of STAS and the distance from the edge of the tumor to the farthest STAS in patients with resected lung adenocarcinoma.

Material and methods

This is a single-institution retrospective observational study. We included all patients with resected lung adenocarcinoma from January 2017 to December 2018 at La Paz University Hospital. The cut-off for the distance from the edge of the tumor to the farthest STAS was 1.5 mm and was assessed by the area under the receiver operating characteristic curve.

Results

A total of 73 patients were included. STAS was found in 52 patients (71.2%). Histological grade 3 (P = 0.035) and absence of lepidic pattern (P = 0.022) were independently associated with the presence of STAS. The median recurrence-free survival (RFS) was 48.06 months [95% confidence interval (CI) 33.58 months to not reached]. STAS-positive patients had shorter median RFS [39.23 months (95% CI 29.34-49.12 months)] than STAS-negative patients (not reached) (P = 0.04). STAS-positive patients with a distance from the edge of the tumor to the farthest STAS ≥1.5 mm had an even shorter median RFS [37.63 months (95% CI 28.14-47.11 months)]. For every 1 mm increase in distance, the risk of mortality increased by 1.26 times (P = 0.04).

Conclusions

Histological grade 3 and absence of lepidic pattern were independently associated with the presence of STAS. STAS was associated with a higher risk of recurrence. The distance from the edge of the tumor to the farthest STAS also had an impact on overall survival.

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Lung adenocarcinoma patients with STAS had higher risk of recurrence.

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Patients with STAS and a distance from the edge of the tumor to the farthest STAS ≥1.5 mm had an even shorter RFS.

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The distance from the edge of the tumor to the farthest STAS also had an impact on overall survival.

Study on the Relationship between Lung Cancer Stromal Cells and Air Cavity Diffusion Based on an Image Acquisition System

Objective. The study aimed to investigate the role of tumor stromal cells in the pathogenesis of STAS, the relationship between air diffusion (STAS) and tumor stromal cells (TSCs) was studied, and the prognostic significance of TSC and STAS in patients with lung adenocarcinoma was evaluated. Methods. A total of 150 patients with lung cancer diagnosed in the Affiliated Hospital of Jiangsu Province were selected. From the perspective of pathology, medical information technology was used to assist the diagnosis. The data of multiple magnetic resonance images were analyzed by three-dimensional space convolution (CNN), fuzzy neural network (FNN), transfinite learning machine (ELM), and binarization. Result. After data fusion, the specificity and sensitivity of multiple magnetic resonance (MRI) data are significantly higher than those of single MRI data, and the more fusion times, the better the sensitivity and specificity. With the increase in the number of information and data fusion, the proportion of the significant effect and the comprehensive effective rate of patients are on the rise. Multiple MRI data fusion examination and analysis under medical information technology can improve the cure rate of patients, and the 1-year survival rate and the 3-year survival rate of patients have also gradually improved. Conclusion. The MRI data fusion diagnosis method under the application of information technology can improve the sensitivity and specificity of the diagnosis results and comprehensively improve the clinical cure rate and the survival rate at different times of prognosis. In the context of the current big data information age, this multifeature fusion analysis technology is playing a more and more important role in medical treatment. The application of this method and technology not only improves the quality of life of patients but also processes multiple types of data at one time only by using the proposed medical assistant diagnosis model, which can save the diagnosis time to a certain extent. It has effectively realized the medical management and medical service quality and has important promotion significance.

An individual nomogram can reliably predict tumor spread through air spaces in non-small-cell lung cancer

Background

Tumor spread through air spaces (STAS) has been shown to adversely affect the prognosis of lung cancer. The correlation between clinicopathological and genetic features and STAS remains unclear.

Method

We retrospectively reviewed 3075 NSCLC patients between2017-2019. We evaluated the relationship between STAS and patients’ clinicopathological and molecular features. The chi-square test was performed to compare categorical variables. Univariate analysis and multivariate logistic regression analysis were performed to investigate the association of clinical factors with STAS. A nomogram was formulated to predict the presence of STAS.

Results

STAS was identified in 617 of 3075 patients (20.07%). STAS was significantly related to sex (p < 0.001), smoking (p < 0.001), CEA (p < 0.001), differentiation (p < 0.001), histopathological type (p < 0.001), lymphatic vessel invasion (p < 0.001), pleural invasion (p < 0.001), T stage (p < 0.001), N stage (p < 0.001), M stage (p < 0.001), and TNM stage (p < 0.001). STAS was frequently found in tumors with wild-type EGFR (p < 0.001), KRAS mutations (p < 0.001), ALK rearrangements (p < 0.001) or ROS1 rearrangements (p < 0.001). For programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1), STAS was associated with PD-L1 expression level in tumor cells (p < 0.001) or stromal cells (p < 0.001), while PD-1 only in stromal cells (p < 0.001). Multivariable analyses demonstrated significant correlations between STAS and CEA level (p < 0.001), pathological grade (p < 0.001), lymphatic vessel invasion (p < 0.001), pleural invasion (p = 0.001), and TNM stage (p = 0.002). A nomogram was formulated based on the results of the multivariable analysis.

Conclusions

Tumor STAS was associated with several invasive clinicopathological features. A nomogram was established to predict the presence of STAS in patients with NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02002-1.

A Prognostic Risk Score Based on Hypoxia-, Immunity-, and Epithelialto-Mesenchymal Transition-Related Genes for the Prognosis and Immunotherapy Response of Lung Adenocarcinoma

Background: Lung adenocarcinoma (LUAD), the most common subtype of non-small cell lung cancer (NSCLC), is associated with poor prognosis. However, current stage-based clinical methods are insufficient for survival prediction and decision-making. This study aimed to establish a novel model for evaluating the risk of LUAD based on hypoxia, immunity, and epithelial-mesenchymal transition (EMT) gene signatures.

Methods: In this study, we used data from TCGA-LUAD for the training cohort and GSE68465 and GSE72094 for the validation cohorts. Immunotherapy datasets GSE135222, GSE126044, and IMvigor210 were obtained from a previous study. Using bioinformatic and machine algorithms, we established a risk model based on hypoxia, immune, and EMT gene signatures, which was then used to divide patients into the high and low risk groups. We analyzed differences in enriched pathways between the two groups, following which we investigated whether the risk score was correlated with stemness scores, genes related to m6A, m5C, m1A and m7G modification, the immune microenvironment, immunotherapy response, and multiple anti-cancer drug sensitivity.

Results: Overall survival differed significantly between the high-risk and low-risk groups (HR = 4.26). The AUCs for predicting 1-, 3-, and 5-year survival were 0.763, 0.766, and 0.728, respectively. In the GSE68465 dataset, the HR was 2.03, while the AUCs for predicting 1-, 3-, and 5-year survival were 0.69, 0.651, and 0.618, respectively. The corresponding values in the GSE72094 dataset were an HR of 2.36 and AUCs of 0.653, 0.662, and 0.749, respectively. The risk score model could independently predict OS in patients with LUAD, and highly correlated with stemness scores and numerous m6A, m5C, m1A and m7G modification-related genes. Furthermore, the risk model was significantly correlated with multiple immune microenvironment characteristics. In the GSE135222 dataset, the HR was 4.26 and the AUC was 0.702. Evaluation of the GSE126044 and IMvigor210 cohorts indicated that PD-1/PD-LI inhibitor treatment may be indicated in patients with low risk scores, while anti-cancer therapy with various drugs may be indicated in patients with high risk scores.

Conclusion: Our novel risk model developed based on hypoxia, immune, and EMT gene signatures can aid in predicting clinical prognosis and guiding treatment in patients with LUAD.

Tumor and Tumor-Associated Macrophage Programmed Death-Ligand 1 Expression Is Associated With Adjuvant Chemotherapy Benefit in Lung Adenocarcinoma

INTRODUCTION

Patients with stage II to III lung adenocarcinomas are treated with adjuvant chemotherapy (ACT) to target the premetastatic niche that persists after curative-intent resection. We hypothesized that the premetastatic niche is a scion of resected lung tumor microenvironment and that analysis of tumor microenvironment can stratify survival benefit from ACT.

METHODS

Using tumor and tumoral stroma from 475 treatment-naive patients with stage II to III lung adenocarcinomas, we constructed a tissue microarray and performed multiplex immunofluorescent staining for immune markers (programmed death-ligand 1 [PD-L1], tumor-associated macrophages [TAMs], and myeloid-derived suppressor cells) and derived myeloid-lymphoid ratio. The association between immune markers and survival was evaluated using Cox models adjusted for pathologic stage.

RESULTS

Patients with high PD-L1 expression on TAMs or tumor cells in resected tumors had improved survival with ACT (TAMs: hazard ratio [HR] = 1.79, 95% confidence interval [CI]: 1.12-2.85; tumor cells: HR = 3.02, 95% CI: 1.69-5.40). Among patients with high PD-L1 expression on TAMs alone or TAMs and tumor cells, ACT survival benefit is pronounced with high myeloid-lymphoid ratio (TAMs: HR = 3.87, 95% CI: 1.79-8.37; TAMs and tumor cells: HR = 2.19, 95% CI: 1.02-4.71) or with high stromal myeloid-derived suppressor cell ratio (TAMs: HR = 2.53, 95% CI: 1.29-4.96; TAMs and tumor cells: HR = 3.21, 95% CI: 1.23-8.35). Patients with low or no PD-L1 expression on TAMs or tumor cells had no survival benefit from ACT.

CONCLUSIONS

Our observation that PD-L1 expression on TAMs or tumor cells is associated with improved survival with ACT provides rationale for prospective investigation and developing chemoimmunotherapy strategies for patients with lung adenocarcinoma.