Integrated molecular characterization reveals potential therapeutic strategies for pulmonary sarcomatoid carcinoma

MSigSeg: An R package for multiple signals segmentation

BACKGROUND AND OBJECTIVE

Identifying breakpoints in signals is crucial for uncovering important features in scientific data. In the biomedical field, the heterogeneity of signals leads to increased complexity in identifying breakpoints. While existing methods and software packages most focus on detecting breakpoints in individual signals, a significant challenge in this field is to detect common breakpoints of multiple signals. To address this challenge, a fast and optimal method has been developed and implemented in the R package MSigSeg as a practical tool.

METHODS

The proposed method utilizes an optimization approach with ℓ-0 norm penalty to efficiently and accurately detect the locations of common breakpoints in multiple signals. This article provides a detailed description of the mathematical problem, the fast optimization algorithm which is implemented in the package, and the usage of core functions along with example datasets.

RESULTS

To evaluate the performance of the proposed method, a simulation study is conducted, comparing it with other segmentation approaches. Real-world problems such as are also processed to demonstrate the practical value of the package. Substantial efficiency gain can be observed by our results.

CONCLUSIONS

Our R package MSigSeg implements an efficient and sensitive method for detecting common breakpoints across multiple signals, serving as a valuable resource for the analysis of intricate biomedical signals. The proposed package is available on the Comprehensive R Archive Network (CRAN) repository https://CRAN.R-project.org/package=MSigSeg.

Integrated molecular characterization reveals the pathogenesis and therapeutic strategies of pulmonary blastoma

Background

Pulmonary blastoma (PB) is a rare subtype of lung cancer. Currently, the underlying pathogenesis mechanisms of PB have not been fully illustrated, and the therapeutic approach for this entity is limited.

Methods

Whole-exome sequencing (WES), RNA sequencing, and DNA methylation profiling are applied to seven PB patients. Multi-omics data of pulmonary sarcomatoid carcinoma (PSC) and pituitary blastoma (PitB) from previous studies are invoked to illuminate the associations among PB and these malignacies.

Results

We portray the genomic alteration spectrum of PB and find that DICER1 is with the highest alteration rate (86 %). We uncover that DICER1 alterations, Wnt signaling pathway dysregulation and IGF2 imprinting dysregulation are the potential pathogenesis mechanisms of PB. Moreover, we reveal that the integrated molecular features of PB are distinct from PSC, and the molecular characteristics of PB are more similar to PitB than to PSC. Pancancer analysis show that the tumor mutation burden (TMB) and leukocyte fraction (LF) of PB are low, while some cases are positive for PD-L1 or have CD8-positive focal areas, implying the potential applicability of immunotherapy in selected PB patients.

Conclusion

This study depicts the integrated molecular characteristics of PB and offers novel insights into the pathogenesis and therapeutic strategies of PB.

Metastatic Pleomorphic Carcinoma of the Lung with Extensive Chromosomal Rearrangements: An Autopsy Case with a Literature Review

We herein report a 47-year-old man who presented with progressive paraparesis. Imaging revealed a right upper pulmonary nodule, massive bilateral adrenal metastases, thoracolumbar vertebral osteolysis, and subcutaneous nodules. A biopsy of the right buttock nodule revealed a poorly differentiated metastatic carcinoma with high programmed cell death-ligand 1 expression and extensive chromosomal rearrangements. The patient died 10 days after the initiation of pembrolizumab treatment. Autopsy findings confirmed pulmonary pleomorphic carcinoma with extensive metastases. Quantification of chromosomal rearrangements revealed a jump-up mutation from the normal karyotype, followed by a further incremental increase in the degree of deviation.

Clinical characteristics and survival outcomes in patients with pulmonary sarcomatoid carcinoma: a multicenter retrospective study

PURPOSE

The clinicopathologic features, mutational status, immunohistochemical markers, and prognosis of Pulmonary sarcomatoid carcinoma (PSC) remain uncertain.

METHODS

This study included 81 PSC and 337 lung adenocarcinomas (LUAD). Progression-free survival (PFS), overall survival (OS), and other clinical data were examined.

RESULTS

46% PSC patients harbored KRAS mutation and 23% harbored EGFR mutation. Univariable analysis identified type and cTNM stage as significant predictor of PFS (type: HR 0.216; 95% CI 0.133-0.349; P < 0.001, cTNM stage: HR 0.483; 95% CI 0.269-0.846; P = 0.014) and OS (type: HR 0.269; 95% CI 0.156-0.465; P < 0.001, cTNM stage: HR 0.435; 95% CI 0.219-0.865; P = 0.018). Multivariable analysis confirmed sex, type and cTNM stage as independent predictors of PFS (sex: HR 2.026; 95%CI 1.027-3.996; P = 0.042; type: HR0.140; 95% CI 0.083-0.238; P < 0.001, cTNM stage: HR0.305; 95% CI 0.165-0.564; P < 0.001) and OS (type: HR0.231; 95% CI 0.132-0.404; P < 0.001, cTNM stage: HR 0.394; 95% CI 0.194-0.797; P = 0.010). Significant differences in PFS (P < 0.0001) and OS (P = 0.022) were observed between PSC and LUAD, and for PC compared with SCC (PFS: P = 0.00036, OS: P = 0.0053). Additionally, PSC patients treated with immunotherapy showed significantly better OS (P = 0.0019) compared with those treated without immunotherapy.

CONCLUSIONS

PSC exhibits high KRAS and EGFR mutation rates, and spindle cell carcinoma has a worse prognosis. Immunotherapy shows potential as a treatment for advanced PSC.

Case report: A golden tail of immunotherapy: significant tail effect in a chemotherapy-resistant advanced pulmonary sarcomatoid carcinoma patient treated by Sintilimab combined with Anlotinib

Tail effect is a unique phenomenon in immunotherapy characterized by the prolonged maintenance of therapeutic efficacy. It can be observable even after treatment cessation. Immunotherapy has gradually become a vital regimen for the treatment of advanced lung cancer patients, among which immune-combined therapies based on immune checkpoint inhibitors (ICIs) have been applied clinically and demonstrates considerable clinical efficacy. In this case report, the patient was pathologically diagnosed with pulmonary sarcomatoid carcinoma (PSC), a rare and highly aggressive subtype of non-small cell lung cancer (NSCLC) known for its poor prognosis due to high invasiveness and metastatic potential. After developing resistance to chemotherapy, the patient was treated with a combined regimen of sintilimab and anlotinib, leading to initial clinical improvement. Following just three cycles of this regimen, treatment was discontinued, and the patient was discharged. Remarkably, over the subsequent months, the patient exhibited a significant tail effect, evidenced by sustained therapeutic stability, continuous tumor regression, stable low levels of serum carcinoembryonic antigen (CEA), and further improvement in clinical symptoms. Tail effect is a golden tail of immunotherapy. This case illustrates that the tail effect of immunotherapy can offer substantial survival benefits for patients with unresectable advanced lung cancer who have failed chemotherapy.

Histological transformation in lung adenocarcinoma: Insights of mechanisms and therapeutic windows

Histological transformation from lung adenocarcinoma (ADC) to small cell lung carcinoma (SCLC), large cell neuroendocrine carcinoma (LCNEC), squamous cell carcinoma (SCC), and sarcomatoid carcinoma (PSC) after targeted therapies is recognized as a mechanism of resistance in ADC treatments. Patients with transformed lung cancer typically experience a poor prognosis and short survival time. However, effective treatment options for these patients are currently lacking. Therefore, understanding the mechanisms underlying histological transformation is crucial for the development of effective therapies. Hypotheses including intratumoral heterogeneity, cancer stem cells, and alteration of suppressor genes have been proposed to explain the mechanism of histological transformation. In this review, we provide a comprehensive overview of the known molecular features and signaling pathways of transformed tumors, and summarized potential therapies based on previous findings.

Tracing Tumor Heterogeneity of Pleomorphic Carcinoma of the Lung

INTRODUCTION

Pulmonary pleomorphic carcinoma (PPC) is an aggressive and highly heterogeneous NSCLC whose underlying biology is still poorly understood.

METHODS

A total of 42 tumor areas from 20 patients with PPC were microdissected, including 39 primary tumors and three metastases, and the histologically distinct components were subjected to whole exome sequencing separately. We further performed in silico analysis of microdissected bulk RNA sequencing and methylation data of 28 samples from 14 patients with PPC. We validated our findings using immunohistochemistry.

RESULTS

The epithelial and the sarcomatoid components of PPCs shared a large number of genomic alterations. Most mutations in cancer driver genes were clonal and truncal between the two components of PPCs suggesting a common ancestor. The high number of alterations in the RTK-RAS pathway suggests that it plays an important role in the evolution of PPC. The metastases morphologically and genetically resembled the epithelial or the sarcomatoid components of the tumor. The transcriptomic and epigenetic profiles of the sarcomatoid components of PPCs with matched squamous-like or adenocarcinoma-like components differed from each other, and they shared more similarities to their matched epithelial components. NCAM1/CD56 was preferentially expressed in the sarcomatoid component of squamous-like PPCs, whereas CDH1/E-Cadherin expression was down-regulated in the sarcomatoid component of most PPCs.

CONCLUSION

Lung adenocarcinoma-like PPCs are mainly driven by RTK-RAS signaling, whereas epithelial-mesenchymal transition programs as highlighted by increased NCAM1 and decreased CDH1 expression govern the epithelial-sarcomatoid transition between the clonally related tumor components. Several alterations in PPCs pinpoint therapeutic opportunities.

Predicting MET exon 14 skipping mutation in pulmonary sarcomatoid carcinoma by whole-tumour texture analysis combined with clinical and conventional contrast-enhanced computed tomography features

Background

Pulmonary sarcomatoid carcinoma (PSC) is a rare, highly malignant type of non-small cell lung cancer (NSCLC) with a poor prognosis. Targeted drugs for MET exon 14 (METex14) skipping mutation can have considerable clinical benefits. This study aimed to predict METex14 skipping mutation in PSC patients by whole-tumour texture analysis combined with clinical and conventional contrast-enhanced computed tomography (CECT) features.

Methods

This retrospective study included 56 patients with PSC diagnosed by pathology. All patients underwent CECT before surgery or other treatment, and both targeted DNA- and RNA-based next-generation sequencing (NGS) were used to detect METex14 skipping mutation status. The patients were divided into two groups: METex14 skipping mutation and nonmutation groups. Overall, 1,316 texture features of the whole tumour were extracted. We also collected 12 clinical and 20 conventional CECT features. After dimensionality reduction and selection, predictive models were established by multivariate logistic regression analysis. Models were evaluated using the area under the curve (AUC), and the clinical utility of the model was assessed by decision curve analysis.

Results

METex14 skipping mutation was detected in 17.9% of PSCs. Mutations were found more frequently in those (I) who had smaller long- or short-axis diameters (P=0.02, P=0.01); (II) who had lower T stages (I, II) (P=0.02); and (III) with pseudocapsular or annular enhancement (P=0.03). The combined model based on the conventional and texture models yielded the best performance in predicting METex14 skipping mutation with the highest AUC (0.89). The conventional and texture models also had good performance (AUC =0.83 conventional; =0.88 texture).

Conclusions

Whole-tumour texture analysis combined with clinical and conventional CECT features may serve as a noninvasive tool to predict the METex14 skipping mutation status in PSC.

The potential contribution of aberrant cathepsin K expression to gastric cancer pathogenesis

The role of cathepsin K (CTSK) expression in the pathogenesis and progression of gastric cancer (GC) remains unclear. Hence, the primary objective of this study is to elucidate the precise expression and biological role of CTSK in GC by employing a combination of bioinformatics analysis and in vitro experiments. Our findings indicated a significant upregulation of CTSK in GC. The bioinformatics analysis revealed that GC patients with a high level of CTSK expression exhibited enrichment of hallmark gene sets associated with angiogenesis, epithelial-mesenchymal transition (EMT), inflammatory response, KRAS signaling up, TNFα signaling via KFκB, IL2-STAT5 signaling, and IL6-JAK-STAT3 signaling. Additionally, these patients demonstrated elevated levels of M2-macrophage infiltration, which was also correlated with a poorer prognosis. The results of in vitro experiments provided confirmation that the over-expression of CTSK leads to an increase in the proliferative and invasive abilities of GC cells. However, further evaluation was necessary to determine the impact of CTSK on the migration capability of these cells. Our findings suggested that CTSK has the potential to facilitate the initiation and progression of GC by augmenting the invasive capacity of GC cells, engaging in tumor-associated EMT, and fostering the establishment of an immunosuppressive tumor microenvironment (TME).

DNA Framework-Based Programmable Atom-Like Nanoparticles for Non-Coding RNA Recognition and Differentiation of Cancer Cells

The cooperative diagnosis of non-coding RNAs (ncRNAs) can accurately reflect the state of cell differentiation and classification, laying the foundation of precision medicine. However, there are still challenges in simultaneous analyses of multiple ncRNAs and the integration of biomarker data for cell typing. In this study, DNA framework-based programmable atom-like nanoparticles (PANs) are designed to develop molecular classifiers for intra-cellular imaging of multiple ncRNAs associated with cell differentiation. The PANs-based molecular classifier facilitates signal amplification through the catalytic hairpin assembly. The interaction between PAN reporters and ncRNAs enables high-fidelity conversion of ncRNAs expression level into binding events, and the assessment of in situ ncRNAs levels via measurement of the fluorescent signal changes of PAN reporters. Compared to non-amplified methods, the detection limits of PANs are reduced by four orders of magnitude. Using human gastric cancer cell lines as a model system, the PANs-based molecular classifier demonstrates its capacity to measure multiple ncRNAs in living cells and assesses the degree of cell differentiation. This approach can serve as a universal strategy for the classification of cancer cells during malignant transformation and tumor progression.

Integrative genomic and transcriptomic profiling of pulmonary sarcomatoid carcinoma identifies molecular subtypes associated with distinct immune features and clinical outcomes

Background

Pulmonary sarcomatoid carcinoma (PSC) is a rare and aggressive subtype of non-small cell lung cancer (NSCLC), characterized by the presence of epithelial and sarcoma-like components. The molecular and immune landscape of PSC has not been well defined.

Methods

Multiomics profiling of 21 pairs of PSCs with matched normal lung tissues was performed through targeted high-depth DNA panel, whole-exome, and RNA sequencing. We describe molecular and immune features that define subgroups of PSC with disparate genomic and immunogenic features as well as distinct clinical outcomes.

Results

In total, 27 canonical cancer gene mutations were identified, with TP53 the most frequently mutated gene, followed by KRAS. Interestingly, most TP53 and KRAS mutations were earlier genomic events mapped to the trunks of the tumors, suggesting branching evolution in most PSC tumors. We identified two distinct molecular subtypes of PSC, driven primarily by immune infiltration and signaling. The Immune High (IM-H) subtype was associated with superior survival, highlighting the impact of immune infiltration on the biological and clinical features of localized PSCs.

Conclusions

We provided detailed insight into the mutational landscape of PSC and identified two molecular subtypes associated with prognosis. IM-H tumors were associated with favorable recurrence-free survival and overall survival, highlighting the importance of tumor immune infiltration in the biological and clinical features of PSCs.

Comprehensive genomic profiling of pulmonary spindle cell carcinoma using tissue and plasma samples: insights from a real-world cohort analysis

Pulmonary spindle cell carcinoma (PSCC) is a rare and aggressive non-small cell lung cancer (NSCLC) subtype with a dismal prognosis. The molecular characteristics of PSCC are largely unknown due to its rarity, which limits the diagnosis and treatment of this historically poorly characterized malignancy. We present comprehensive genomic profiling results of baseline tumor samples from 22 patients histologically diagnosed with PSCC, representing the largest cohort to date. Somatic genetic variant detection was compared between paired plasma samples and primary tumors from 13 patients within our cohort. The associations among genomic features, treatment, and prognosis were also analyzed in representative patient cases. TP53 (54.5%), TERT (36.4%), CDKN2A (27.3%), and MET (22.7%) were most frequently mutated. Notably, 81.8% of patients had actionable targets in their baseline tumors, including MET (22.7%), ERBB2 (13.6%), EGFR (9.1%), KRAS (9.1%), ALK (9.1%), and ROS1 (4.5%). The median tumor mutation burden (TMB) for PSCC tumors was 5.5 mutations per megabase (muts/Mb). TMB-high tumors (>10 muts/Mb) exhibited a significantly higher mutation frequency in genes such as KRAS, ARID2, FOXL2, and LRP1B, as well as within the DNA mismatch repair pathway. The detection rates for single nucleotide variants and structural variants were comparable between matched tumor and plasma samples, with 48.6% of genetic variants being mutually identified in both sample types. Additionally, a patient with a high mutation load and positive PD-L1 expression demonstrated a 7-month survival benefit from chemoimmunotherapy. Furthermore, a patient with an ALK-rearranged tumor achieved a remarkable 3-year progression-free survival following crizotinib treatment. Overall, our findings deepen the understanding of the complex genomic landscape of PSCC, revealing actionable targets amenable to tailored treatment of this poorly characterized malignancy.

Genomic Landscape of Pulmonary Sarcomatoid Carcinoma

PURPOSE

Pulmonary sarcomatoid carcinoma (PSC) is a rare aggressive subtype of non-small cell lung cancer (NSCLC) with limited therapeutic strategies. We attempted to elucidate the evolutionary trajectories of PSC using multiregional and longitudinal tumor samples.

MATERIALS AND METHODS

A total of 31 patients were enrolled in this study and 11 longitudinal samples were available from them. Using whole exome sequencing data, we analyzed the mutational signatures in both carcinomatous and sarcomatous areas in primary tumors of the 31 patients and longitudinal samples obtained from 11 patients. Furthermore, digital droplet polymerase chain reaction (ddPCR), and programmed death-ligand 1 (PD-L1) immunohistochemistry using the Ventana SP263 assay were performed.

RESULTS

TP53 was identified as the most frequently altered gene in the primary (74%) and metastatic (73%) samples. MET exon 14 skipping mutations, confirmed by ddPCR, and TP53 mutations were mutually exclusive; whereas, MET exon 14 skipping mutations frequently co-occurred with MDM2 amplification. Metastatic tumors showed dissimilar genetic profiles from either primary component. During metastasis, the signatures of APOBEC decreased in metastatic lesions compared with that in primary lesions. PSC showed higher MET and KEAP1 mutations and stronger PD-L1 protein expression compared with that recorded in other NSCLCs.

CONCLUSION

Decreased APOBEC signatures and subclonal diversity were detected during malignant progression in PSC. Frequent MET mutations and strong PD-L1 expression distinguished PSC from other NSCLCs. The aggressiveness and therapeutic difficulties of PSC were possibly attributable to profound intratumoral and intertumoral genetic diversity. Next-generation sequencing could suggest the appropriate treatment strategy for PSC.

Biological characteristics and clinical treatment of pulmonary sarcomatoid carcinoma: a narrative review

Background and Objective

Pulmonary sarcomatoid carcinoma (PSC) is a subset of non-small cell lung cancer (NSCLC) with highly malignant, aggressive, and heterogeneous features. Patients with this disease account for approximately 0.1-0.4% of lung cancer cases. The absence of comprehensive summaries on the basic biology and clinical treatments for PSC means there is limited systematic awareness and understanding of this rare disease. This paper provides an overview of the biological characteristics of PSC and systematically summarizes various treatment strategies available for patients with this disease.

Methods

For this narrative review, we have searched literature related to the basic biology and clinical treatment approaches of PSC by searching the PubMed database for articles published from July 16, 1990 to August 29, 2023. The following keywords were used: "pulmonary sarcomatoid carcinoma", "genetic mutations", "immune microenvironment", "hypoxia", "angiogenesis", "overall survival", "surgery", "radiotherapy", "chemotherapy", and "immune checkpoint inhibitors".

Key Content and Findings

Classical PSC comprises epithelial and sarcomatoid components, with most studies suggesting a common origin. PSC exhibits a higher tumor mutational burden (TMB) and mutation frequency than other types of NSCLC. The tumor microenvironment (TME) of PSC is characterized by hypoxia, hypermetabolism, elevated programmed cell death protein 1/programmed cell death-ligand 1 expression, and high immune cell infiltration. Treatment strategies for advanced PSC are mainly based on traditional NSCLC treatments, but PSC exhibits resistance to chemotherapy and radiotherapy. The advancement of genome sequencing has introduced targeted therapies as an option for mutation-positive PSC cases. Moreover, due to the characteristics of the immune microenvironment of PSC, many patients positively respond to immunotherapy, demonstrating its potential for the management of PSC.

Conclusions

Although several studies have examined and assessed the TME of PSC, these are limited in quantity and quality, presenting challenges for research into the clinical treatment strategies for PSC. With the emergence of new technologies and the advancement of clinical research, for example, savolitinib's clinical study for MET exon 14 skipping mutations positive PSC patients have shown promising outcomes, more in-depth studies on PSC are eagerly anticipated.

Effectiveness and Safety of Immune Checkpoint Inhibitors Alone or in Combination With Chemotherapy in Pulmonary Sarcomatoid Carcinoma

Introduction

Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of lung cancer associated with poor prognosis and resistance to conventional chemotherapy. Immune checkpoint inhibitors (ICIs), alone or in combination with chemotherapy, were found to have clinical benefits in PSC in recent studies. Nevertheless, because these studies included a small number of patients owing to disease rarity, larger studies are needed to evaluate the effectiveness and safety of ICI-based therapy for PSC.

Methods

This multicenter retrospective study evaluated patients with ICI-naive advanced or metastatic PSC who were treated with ICI-based therapy at 25 hospitals in Japan.

Results

A total of 124 patients were evaluated. The overall response rate, median progression-free survival (PFS), and median overall survival (OS) were 59.0%, 10.5 months, and 32.8 months, respectively. The PFS and OS rates at 24 months were 35.3% and 51.5%, respectively. Programmed death-ligand 1 expression, concomitant chemotherapy, and the treatment line were not significantly associated with PFS or OS. Immune-related adverse events (irAEs) were observed in 70 patients (56.5%), including 30 (24.2%) with grade 3 to 5 events. Patients with mild irAEs (grades 1-2) had longer PFS and OS than did those with severe (grades 3-5) or no irAEs. In a multivariate analysis, any-grade irAEs and the absence of liver metastases were independently associated with PFS, whereas any-grade irAEs and Eastern Cooperative Oncology Group performance status less than or equal to 1 were independently associated with OS.

Conclusions

ICI-based therapy was found to have promising effectiveness in patients with advanced or metastatic PSC, regardless of programmed death-ligand 1 expression, concomitant chemotherapy, or treatment line.

Pembrolizumab combined with anlotinib improves therapeutic efficacy in pulmonary sarcomatoid carcinoma with TMB-H and PD-L1 expression: a case report and literature review

Background

Pulmonary sarcomatoid carcinoma (PSC) is a unique subtype of non-small cell lung cancer (NSCLC) with a high degree of malignancy and poor therapeutic effects. With the widespread use of immune checkpoint inhibitors (ICIs) in recent years, few studies have reported that immunotherapy is effective against PSC. As a multi-target anti-vascular targeting agent, anlotinib showed a better anti-tumor effect in various cancer species. The paper reported the therapeutic and side effects of pembrolizumab combined with anlotinib in a patient with advanced PSC.

Case presentation

This is a 73 year old female patient who underwent thoracoscopy right upper lobectomy and was diagnosed as locally advanced PSC. However, the patient experienced tumor recurrence and metastasis 7 weeks after surgery and was unable to tolerate chemoradiotherapy. Moreover, she detected TP53 mutation and found that tumor mutation burden (TMB) and PD-L1 were high expression. Therefore, the patient received pembrolizumab combined with anlotinib treatment. After 15 cycles of treatment, the tumor significantly shrank with no tumor activity. The evaluation of tumor efficacy is partial response (PR). During the treatment period, she experienced one-degree thyroid-stimulating hormone elevation and two-degree hand-foot syndrome. Pembrolizumab and anlotinib was continued for two years as a maintenance treatment. The patient had a good quality of life and no disease progression was observed. Currently, the patient is still alive without tumor progression and has overall survival exceeding 45 months and toxic side effects were tolerable.

Conclusions

Combining ICIs and anti-angiogenic targeted therapy has brought new hope in treating advanced PSC. Additionally, TMB and PD-L1 expression could be potential predictive biomarkers of the efficacy in advanced PSC with immunotherapy.

Anlotinib combined with pembrolizumab as first-line treatment for advanced pulmonary sarcomatoid carcinoma: a case report and literature review

Pulmonary sarcomatoid carcinoma (PSC) is an uncommon variant of non-small cell lung cancer (NSCLC), known for its unfavorable prognosis. Previous studies have elucidated that PSC generally exhibits a significant expression of programmed death-ligand 1 (PD-L1), an elevated tumor mutation burden, and marked vascular invasion. These factors imply the possible effectiveness of treatments like immunotherapy and anti-angiogenic therapy. The subject of this case was a 65-year-old male diagnosed with advanced PSC, characterized by high PD-L1 expression and devoid of known driver gene mutations. Owing to the restrictions imposed by the COVID-19 pandemic, the patient initially underwent home-based treatment with anlotinib, which led to symptomatic improvement after a single treatment cycle. Subsequent hospitalization allowed for the administration of anlotinib plus Pembrolizumab, resulting in a partial response. Radiotherapy was necessitated due to local disease progression. But after 15 cycles of treatment with Pembrolizumab, hyperprogression was observed. The patient's overall survival spanned 14 months, with no evident adverse reactions to the medications. Genomic analysis revealed potential associations between treatment efficacy and mutations in the TP53, NF1, and MET genes. This case underscores the effectiveness and safety of a first-line treatment regimen combining pan-target anti-angiogenic therapy (anlotinib) with anti-tumor immunotherapy.

Survival analysis and nomogram for pulmonary sarcomatoid carcinoma: an SEER analysis and external validation

OBJECTIVE

Uncommon and particularly deadly, pulmonary sarcomatoid carcinoma (PSC) is an aggressive type of lung cancer. This research aimed to create a risk categorisation and nomogram to forecast the overall survival (OS) of patients with PSC.

METHODS

To develop the model, 899 patients with PSC were taken from the Surveillance, Epidemiology, and End Results database from the USA. We also used an exterior verification sample of 34 individuals with PSC from Fujian Provincial Hospital in China. The Cox regression hazards model and stepwise regression analysis were done to screen factors in developing a nomogram. The nomogram's ability to discriminate was measured employing the area under a time-dependent receiver operating characteristic curve (AUC), the concordance index (C-index) and the calibration curve. Decision curve analysis (DCA) and integrated discrimination improvement (IDI) were used to evaluate the nomogram to the tumour-node-metastasis categorisation developed by the American Joint Committee on Cancer (AJCC-TNM), eighth edition, and an additional sample confirmed the nomogram's accuracy. We further developed a risk assessment system based on nomogram scores.

RESULTS

Six independent variables, age, sex, primary tumour site, pathological group, tumour-node-metastasis (TNM) clinical stage and therapeutic technique, were chosen to form the nomogram's basis. The nomogram indicated good discriminative ability with the C-index (0.763 in the training cohort and 0.746 in the external validation cohort) and time-dependent AUC. Calibration plots demonstrated high congruence between the prediction model and real-world evidence in both the validation and training cohorts. Nomogram outperformed the AJCC-TNM eighth edition classification in both DCA and IDI. Patients were classified into subgroups according to their risk ratings, and significant differences in OS were observed between them (p<0.001).

CONCLUSION

We conducted a survival analysis and nomogram for PSC. This developed nomogram holds potential to serve as an efficient tool for clinicians in prognostic modelling.

Programmed Cell Death Protein 1 Inhibitors and MET Targeted Therapies in NSCLC With MET Exon 14 Skipping Mutations: Efficacy and Toxicity as Sequential Therapies

Introduction

NSCLC with MET exon 14 skipping mutation (METex14) is associated with poor outcomes. Integration of novel targeted therapies is challenging because of barriers in testing and drug access. We, therefore, sought to characterize the treatment patterns, outcomes, and emerging issues of treatment sequencing in patients with METex14-mutant NSCLC.

Methods

We reviewed all NSCLC cases with METex14 alterations between 2014 and 2020 across four Canadian cancer centers. Demographics, disease characteristics, systemic therapy, overall response rates (ORRs), survival, and toxicity were summarized.

Results

Among 64 patients with METex14-mutant NSCLC, the median overall survival was 23.1 months: 127.0 months in stage 1, 27.3 months in resected stage 2 and 3, and 16.6 months in unresectable stage 3 or 4 disease, respectively. In patients with advanced disease, 22% were too unwell for systemic treatment. MET tyrosine kinase inhibitors (TKIs) were administered to 28 patients with an ORR of 33%, median progression-free survival of 2.7 months, and 3.8 months for selective TKIs. Programmed cell death protein-1 (PD-1) inhibitors were given to 25 patients-the ORR was 44% and progression-free survival was 10.6 months. No responses were seen with subsequent MET TKIs after initial TKI treatment. Grade 3 or higher toxicities occurred in 64% of patients who received MET TKI after PD-1 inhibitors versus 8% in those who did not receive PD-1 inhibitors.

Conclusions

Many patients with advanced METex14 NSCLC were too unwell to receive treatment. PD-1 inhibitors seem effective as an initial treatment, although greater toxicity was seen with subsequent MET TKIs. Thus, timely testing for METex14 skipping and initial therapy are imperative to improving patient survival.

Primary Pulmonary Carcinomas with Spindle and/or Giant Cell Features: A Review with Emphasis in Classification and Pitfalls in Diagnosis

Primary carcinomas of the lung are vastly represented by the conventional types of adenocarcinomas or squamous cell carcinomas. However, there are other types of non-small cell carcinomas that although uncommon represent a meaningful group that often pose a problem not only in diagnosis but also in classification. Spindle cell and/or giant cell carcinomas, although uncommon represent an important group of primary lung carcinomas. Important to highlight is that current criteria are rather ambiguous and likely not up to date, which renders the classification of these tumors somewhat more obscure. In addition, with the daily use of immunohistochemical stains, the classification of these tumors may also pose a different problem in the proper allocation of these tumors. Proper classification is highly important in the selection process that takes place using such material for molecular analysis. The current molecular characteristics of these tumors are limited and lack more in-depth studies and analyses that can provide specific targets for the treatment of patients with these tumors. The current review attempts to highlight the shortcomings in the current classification and definitions of these neoplasms as well as the more current view regarding these tumors when the use of immunohistochemical stains is employed.

An advanced pulmonary sarcomatoid carcinoma patient harboring a BRAFV600E mutation responds to dabrafenib and trametinib: a case report and literature review

Background

The pulmonary sarcomatoid carcinoma (PSC) is a rare and aggressive subtype of NSCLC with rapid progression and poor prognosis, and is resistant to conventional chemotherapy. Most PSC cases have potential targetable genomic alterations. Approximately 7% of PSC patients have BRAF mutations, and the efficacy of dabrafenib and trametinib in BRAFV600E mutated PSC is unclear.

Case presentation

Our report describes a patient with mutated BRAFV600E PSC who underwent surgery and adjuvant chemotherapy early but quickly relapsed. Both chemotherapy and immunotherapy were ineffective for him, combined dabrafenib and trametinib produced a 6-month progression-free survival, and a partial response was observed in the tumor response evaluation. As a result of financial pressure, he stopped taking the targeted drugs, and his disease rapidly progressed.

Conclusion

Dabrafenib combined with trametinib provides partial remission in patients with advanced PSC with BRAFV600E mutations, and large-scale NGS panels could offer more options for PSC treatment.

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.

Integrated Clinical, Molecular and Immunological Characterization of Pulmonary Sarcomatoid Carcinomas Reveals an Immune Escape Mechanism That May Influence Therapeutic Strategies

Pulmonary sarcomatoid carcinoma (PSC) has highly aggressive biological behaviour and poor clinical outcomes, raising expectations for new therapeutic strategies. We characterized 179 PSC by immunohistochemistry, next-generation sequencing and in silico analysis using a deep learning algorithm with respect to clinical, immunological and molecular features. PSC was more common in men, older ages and smokers. Surgery was an independent factor (p < 0.01) of overall survival (OS). PD-L1 expression was detected in 82.1% of all patients. PSC patients displaying altered epitopes due to processing mutations showed another PD-L1-independent immune escape mechanism, which also significantly influenced OS (p < 0.02). The effect was also maintained when only advanced tumour stages were considered (p < 0.01). These patients also showed improved survival with a significant correlation for immunotherapy (p < 0.05) when few or no processing mutations were detected, although this should be interpreted with caution due to the small number of patients studied. Genomic alterations for which there are already approved drugs were present in 35.4% of patients. Met exon 14 skipping was found more frequently (13.7%) and EGFR mutations less frequently (1.7%) than in other NSCLC. In summary, in addition to the divergent genomic landscape of PSC, the specific immunological features of this prognostically poor subtype should be considered in therapy stratification.

Demographics and Clinicopathologic Profile of Pulmonary Sarcomatoid Carcinoma with Survival Analysis and Genomic Landscape

Background: Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of non-small cell lung cancer (NSCLC) with an aggressive clinical nature and poor prognosis. With novel targeted therapeutics being developed, new ways to effectively treat PSC are emerging. In this study, we analyze demographics, tumor characteristics, treatment modalities, and outcomes of PSC and genetic mutations in PSC. Methods: Data from the Surveillance, Epidemiology, and End Results (SEER) database were reviewed to analyze cases of pulmonary sarcomatoid carcinoma from 2000 to 2018. The molecular data with the most common mutations in PSC were extracted from the Catalogue Of Somatic Mutations in Cancer (COSMIC) database. Results: A total of 5259 patients with PSC were identified. Most patients were between 70 and 79 years of age (32.2%), male (59.1%), and Caucasian (83.7%). The male-to-female ratio was 1.45:1. Most tumors were between 1 and 7 cm in size (69.4%) and poorly differentiated (grade III) (72.9%). The overall 5-year survival was 15.6% (95% confidence interval (95% CI) = 14.4-16.9)), and the cause-specific 5-year survival was 19.7% (95% CI = 18.3-21.1). The five-year survival for those treated with each modality were as follows: chemotherapy, 19.9% (95% CI = 17.7-22.2); surgery, 41.7% (95% CI = 38.9-44.6); radiation, 19.1% (95% CI = 15.1-23.5); and multimodality therapy (surgery and chemoradiation), 24.8% (95% CI = 17.6-32.7). On multivariable analysis, age, male gender, distant stage, tumor size, bone metastasis, brain metastasis, and liver metastasis were associated with increased mortality, and chemotherapy and surgery were associated with reduced mortality (p < 0.001). The best survival outcomes were achieved with surgery. The most common mutations identified in COSMIC data were TP53 31%, ARID1A 23%, NF1 17%, SMARCA4 16%, and KMT2D 9%. Conclusions: PSC is a rare and aggressive subtype of NSCLC, usually affecting Caucasian males between 70 and 79. Male gender, older age, and distant spread were associated with poor clinical outcomes. Treatment with surgery was associated with better survival outcomes.

Complete response to chemoimmunotherapy with bevacizumab in synchronous multiple primary cancers: pulmonary adenocarcinoma and sarcomatoid carcinoma

A small percentage of patients have multiple synchronous primary cancers at presentation. In the last five years, many regimens associated with immunotherapy and chemotherapy were approved for first-line metastatic non-small-cell lung cancer (NSCLC) and other solid tumors, but the study of immunotherapy when multiple cancers are present in one patient remains incomplete. Next-generation sequencing biomarkers and immunotherapy markers including PD-L1 can be effectively utilized in the diagnosis and treatment plan for multiple synchronous primary cancers. Immune biomarkers and PD-L1 expression warrant individualized treatments in synchronous primary adenocarcinoma and pulmonary sarcomatoid carcinoma. We describe the case of a patient with pulmonary sarcomatoid carcinoma and lung adenocarcinoma, metastatic to brain de novo. The patient achieved a complete response after only three cycles of carboplatin, paclitaxel, bevacizumab, and atezolizumab and remains free of any evidence of disease after 18 mo of maintenance therapy.

Pulmonary Spindle Cell Carcinoma Presenting Anaplastic Lymphoma Kinase Rearrangement

Pulmonary spindle cell carcinoma is a subtype of pulmonary sarcomatoid carcinoma and a very rare tumor type with a poor prognosis. A few case reports have documented patients with pulmonary sarcomatoid carcinoma with anaplastic lymphoma kinase rearrangement, and the efficacy and outcomes of anaplastic lymphoma kinase inhibitors remain unclear. Herein, we present the case of a 60-year-old woman with stage IVB disease who was diagnosed with a metastatic brain tumor. This patient showed high levels of programmed cell death ligand 1 expression and anaplastic lymphoma kinase rearrangement and received pembrolizumab as the first-line treatment. Three weeks later, pembrolizumab failed to reduce the size of the primary pulmonary tumor, and the patient's general condition did not improve. The patient received alectinib as the second-line treatment. Two months later, multiple brain metastases were observed. Hence, whole-brain irradiation was performed as treatment for multiple brain metastases, while another anaplastic lymphoma kinase inhibitor was administered; however, both treatments remained ineffective. The patient eventually died 9 months after the initiation of first-line treatment. The present case report describes the therapeutic course of a patient with pulmonary spindle cell carcinoma with an anaplastic lymphoma kinase rearrangement.

Partial response to pralsetinib in an advanced pulmonary sarcomatoid carcinoma patient harboring a KIF5B-RET rearrangement: a case report

BACKGROUND

Pulmonary sarcomatoid carcinoma (PSC) is a rare and unconventional non-small-cell lung cancer (NSCLC) that appears to be aggressive, with a poor prognosis and response to conventional treatment. Approximately 30% of PSCs have potentially targetable genomic alterations, but few studies have involved RET gene fusions, and corresponding targeted therapies are lacking.

CASE PRESENTATION

In this report, we describe a patient with PSC harboring a KIF5B-RET gene fusion who was initially diagnosed with stage IVb lung cancer. Due to the poor performance status, the patient was unable to tolerate any radiotherapy or chemotherapy. Based on the next-generation sequencing (NGS) result of RET gene fusion, the patient was treated with pralsetinib. Two months after the treatment, the patient achieved a partial response.

CONCLUSIONS

Our case indicates that RET is one of the main driver oncogenes of PSC and provides useful information for precise RET inhibitor administration in the future. Thus, the use of comprehensive genomic profiling may provide important treatment options for PSC.

Targeting 4-1BB and PD-L1 induces potent and durable antitumor immunity in B-cell lymphoma

Introduction

Although PD-1/L1 mAb has demonstrated clinical benefits in certain cancer types, low response rate and resistance remain the main challenges for the application of these immune checkpoint inhibitors (ICIs). 4-1BB is a co-stimulator molecule expressed in T cells, which could enhance T cell proliferation and activation. Herein, the synergetic antitumor effect and underlying mechanism of 4-1BB agonist combined with PD-1/PD-L1 blockade were determined in B-cell lymphoma (BCL).

Methods

Subcutaneous transplantation BCL tumor models and metastasis models were established to evaluate the therapeutic effect of PD-L1 antibody and/or 4-1BB agonist in vivo. For the mechanistic study, RNA-seq was applied to analyze the tumor microenvironment and immune-related signal pathway after combination treatment. The level of IFN-γ, perforin, and granzyme B were determined by ELISA and Real-time PCR assays, while tumor-infiltrating T cells were measured by flow cytometry and immunohistochemical analysis. CD4/CD8 specific antibodies were employed to deplete the related T cells to investigate the role CD4+ and CD8+ T cells played in combination treatment.

Results

Our results showed that combining anti-PD-L1 ICI and 4-1BB agonists elicited regression of BCL and significantly extended the survival of mice compared to either monotherapy. Co-targeting PD-L1 and 4-1BB preferentially promoted intratumoral cytotoxic lymphocyte infiltration and remodeled their function. RNA-sequence analysis uncovered a series of up-regulated genes related to the activation and proliferation of cytotoxic T lymphocytes, further characterized by increased cytokines including IFN-γ, granzyme B, and perforin. Furthermore, depleting CD8+ T cells not CD4+ T cells totally abrogated the antitumor efficacy, indicating the crucial function of the CD8+ T cell subset in the combination therapy.

Discussion

In summary, our findings demonstrated that 4-1BB agonistic antibody intensified the antitumor immunity of anti-PD-1/PD-L1 ICI via promoting CD8+ T cell infiltration and activation, providing a novel therapeutic strategy to BCL.

Immune checkpoint inhibitors plus chemotherapy in patients with locally advanced or metastatic pulmonary sarcomatoid carcinoma: a multicentric real-world study

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have demonstrated promising efficacy as monotherapy in patients with pulmonary sarcomatoid carcinoma (PSC). We performed the current multi-institutional, real-world study to assess the efficacy of ICIs plus chemotherapy in patients with PSC.

METHODS

All consecutive patients with locally advanced or metastatic PSC from three centers treated with ICIs between January 2018 and July 2021 were enrolled. Programmed death ligand 1 (PD-L1) expression was stained and evaluated using immunohistochemical with 22C3. Single-cell RNA sequencing (scRNA-seq) was performed in two patients with PSC and two patients with adenocarcinoma to understand the cell-type-specific transcriptome landscape of cancer cells and tumor microenvironment (TME) of PSC.

RESULTS

A cohort of 42 PSC patients was identified. In the overall population, the objective response rate (ORR) was 73.8%, median progression-free survival (mPFS) was 10.3 months and median overall survival was not reached and 2-year survival rate was 51.2%. For 34 treatment-naïve patients who received first-line ICIs plus chemotherapy, the ORR was 70.6%, mPFS was 10.3 months and 2-year survival rate was 57.8%. In patients with PD-L1 tumor proportion score (TPS) < 1%, 1-49%, and ⩾50%, the ORR was 33.3%, 72.7%, and 85.7% and mPFS was 6.0, 6.7, and 10.3 months, respectively. Notably, two patients with transformed PSC from lung adenocarcinoma after epidermal growth factor receptor-tyrosine kinase inhibitor treatment also responded well to ICIs plus chemotherapy. scRNA-seq revealed immune-cell-inflamed TME, lower intratumoral heterogeneity, and activated immune response pathway in PSC.

CONCLUSIONS

Our study demonstrated remarkable efficacy of ICIs plus chemotherapy as first-line therapy for patient with locally advanced or metastatic PSC.

Clinical analysis of 78 pulmonary sarcomatoid carcinomas with surgical treatment

OBJECTIVE

To evaluate clinical factors influencing the postoperative pulmonary sarcomatoid carcinoma (PSCs) prognosis.

METHODS

We retrospectively evaluated patients with PSCs treated from October 2012 to October 2017. Kaplan-Meier survival curves were calculated using univariable analysis (log-rank test). Univariable/multivariable Cox regression analysis was also performed.

RESULTS

Mixed PSCs were most common (64.10%). Pure PSCs occurred more often with large tumors compared with mixed PSCs. Patients with vs without pleural retraction, respectively, had significantly worse overall survival (OS; 16 vs 23 months) and disease-free survival (DFS; 11 vs 20 months), and patients with airway dissemination had significantly shorter OS (14 vs 21 months) and DFS (11 vs 20 months). Patients with PSC with an adenocarcinoma component had favorable OS. Airway dissemination, pleural retraction, metastatic mediastinal lymph node (LN) number, and pathological tumor-node-metastasis (pTNM) stage were risk factors for short OS. Neither adjuvant chemotherapy nor adjuvant radiotherapy provided a survival advantage. Airway dissemination was an independent prognostic factor (odds ratio, 1.87; 95% confidence interval, 1.04-3.36).

CONCLUSION

Pure PSCs were more likely with large tumors compared with mixed PSCs. Airway dissemination, pleural retraction, and metastatic mediastinal LN number were associated with OS. Airway dissemination was an independent prognostic factor.

Pten and p53 Loss in the Mouse Lung Causes Adenocarcinoma and Sarcomatoid Carcinoma

Simple Summary

Lung cancer is the world leading cause of cancer death. Therefore, a better understanding of the disease is needed to improve patient survival. In this work, we have deleted the tumor suppressor genes Pten and Trp53 in adult mouse lungs to analyze its impact on tumor formation. Double mutant mice develop Adenocarcinoma and Pulmonary Sarcomatoid Carcinoma, two different types of Non-Small Cell Carcinoma whose biological relationships are a matter of debate. The former is very common, with various models described and some therapeutic options. The latter is very rare with very poor prognosis, no effective treatment and lack of models reported so far. Interestingly, this study reports the first mouse model of pulmonary sarcomatoid carcinoma available for preclinical research.

Abstract

Lung cancer remains the leading cause of cancer deaths worldwide. Among the Non-Small Cell Carcinoma (NSCLC) category, Adenocarcinoma (ADC) represents the most common type, with different reported driver mutations, a bunch of models described and therapeutic options. Meanwhile, Pulmonary Sarcomatoid Carcinoma (PSC) is one of the rarest, with very poor outcomes, scarce availability of patient material, no effective therapies and no models available for preclinical research. Here, we describe that the combined deletion of Pten and Trp53 in the lungs of adult conditional mice leads to the development of both ADC and PSC irrespective of the lung targeted cell type after naphthalene induced airway epithelial regeneration. Although this model shows long latency periods and incomplete penetrance for tumor development, it is the first PSC mouse model reported so far, and sheds light on the relationships between ADC and PSC and their cells of origin. Moreover, human ADC show strong transcriptomic similarities to the mouse PSC, providing a link between both tumor types and the human ADC.

Molecular and expressional characterization of tumor heterogeneity in pulmonary carcinosarcoma

The genetic concordance and heterogeneity of the two components of pulmonary carcinosarcoma (PCS), carcinoma, and sarcoma, have not been fully elucidated because of its rare occurrence. We performed targeted sequencing of the carcinoma and sarcoma components of four PCSs to identify genetic similarities and differences. Formalin-fixed paraffin-embedded tissue samples were macroscopically or microscopically dissected. DNA was extracted from each component, and genetic alterations were analyzed separately. Moreover, we performed RNA-seq analysis on both components of one PCS to compare differences in gene expression profiles. The carcinoma part consisted of adenocarcinoma in two cases, squamous cell carcinoma in one, and adenosquamous carcinoma in the last. TP53 mutation was observed in three samples from the trunk, although it was detected only in the sarcoma part in one case. No specific driver gene mutation was observed; however, KRAS mutations were observed in one case in the trunk. RNA-seq analysis revealed that the rhabdomyosarcoma component expressed various genes related to muscle development, whereas the carcinoma component did not; and that gene expression overall was completely different between the two components. Our study revealed that the two different components of PCS shared common gene mutations in most cases. Although gene expression was different among components, if driver genes such as KRAS were detected in PCS, molecular targeted therapy could be beneficial even when the tumor contains a sarcoma component.

PSC subtyping based on TTF-1 and p40 expression reveals distinct molecular characteristics and therapeutic strategies

Pulmonary sarcomatoid carcinoma (PSC) is a unique form of poorly differentiated non-small cell lung cancer (NSCLC) and is notorious for its highly malignant nature and dismal prognosis. To introduce effective treatment for PSC patients, precise subtyping of PSC is demanding. In our study, TTF-1 and P40 immunohistochemistry (IHC) staining were applied to 56 PSC patients with multi-omics data. According to IHC results, we categorized these patients into three subgroups and profiled their molecular contexture using bioinformatic skills. IHC results classified these patients into three subgroups: TTF-1 positive subgroup (n=27), P40 positive subgroup (n=15), and double-negative subgroup (n=14). Spindle cell samples accounted for 35.71% (5/14) of double-negative patients, higher than others (p=0.034). The three subgroups were heterogeneous in the genomic alteration spectrum, showing significant differences in the RTK/RAS pathway (p=0.004) and the cell cycle pathway (p=0.030). The methylation profile of the double-negative subgroup was between the other two subgroups. In similarity analysis, the TTF-1 and p40 subgroups were closely related to LUAD and LUSC, respectively. The TTF-1 positive subgroup had the highest leukocyte fraction (LF) among several cancer types, and the tumor mutation burden (TMB) of the p40 positive subgroup ranked third in the TMB list, suggesting the applicability of immunotherapy for PSC. The study established a new subtyping method of PSC based on IHC results and reveals 3 subgroups with distinct molecular features, providing evidence for refined stratification in the treatment of PSC. This article is protected by copyright. All rights reserved.

Genomic Variations and Immune-Related Features of TMB, PD-L1 Expression and CD8+ T Cell Infiltration in Chinese Pulmonary Sarcomatoid Carcinoma

Background

Pulmonary sarcomatoid carcinoma (PSC) is a rare and distinct subtype of lung cancer characterized by its aggressiveness and dismal prognosis. However, genomic landscape and immune contexture have not been fully elucidated among PSC patients.

Methods

In the present study, whole-exome-sequencing (WES) analyses were performed to depict genomic landscape of 38 independent PSC samples. Tumor mutation burden (TMB) was calculated with the total number of non-synonymous SNVs and indel variants per megabase of coding regions. PD-L1 expression and CD8⁺ T cell density were evaluated by immunohistochemistry in PSC samples. Their associations with genomic mutation were further assessed in genes with most frequent mutation. Overall survival (OS) of PSC patients with top mutated genes and high and low TMB, PD-L1 and CD8⁺ TIL expressions were further compared. Subgroup analyses of OS stratified by morphology and pathological type were conducted. Their correlation with TMB, PD-L1 and CD8⁺ T cell were further assessed.

Results

We identified a cohort of genomic and somatic mutation in PSC patients. Subgroup patients with distinct clinicopathological features were found to harbor different genomic mutations and immunologic features. Besides, genomic profiles influenced outcomes, with SARS mutation associated with worsened prognosis.

Conclusion

Through the mapping of genetic and immunologic landscape, we find the heterogeneity among the subgroups of PSC. Our findings may provide opportunities for therapeutic susceptibility among Chinese PSC patients.

Multimodality Treatment of Pulmonary Sarcomatoid Carcinoma: A Review of Current State of Art

Pulmonary sarcomatoid carcinoma (PSC) is an unconventional non-small-cell lung cancer (NSCLC) that is currently managed under guidelines used for conventional NSCLC and has poor survival. Surgery is the optimal choice for resectable PSC, and the prevalence of mutations in this type of tumor laid the foundation for novel systemic therapies such as targeted therapy and immunotherapy. PSC is resistant to chemotherapy and radiotherapy, and the effects of the 2 therapies are controversial. Targeted therapies have been reported to confer survival benefits, and savolitinib, an oral selective MET tyrosine-kinase inhibitor, has been approved in metastatic patients with MET exon 14 skipping mutations. Expression and positive rate of programmed death ligand 1 in PSC are high; our previous research has also revealed a high mutational burden and a T-cell-inflamed microenvironment of PSC. Correspondingly, immune checkpoint inhibitors have shown preliminary antitumor effects (overall response rates of 40.5% (15/37) and 31.6% (6/19) in two retrospective studies, respectively) in PSC patients. In summary, patients should receive operations at an early stage and multimodality treatments are needed to maximize the benefits of patients with advanced disease.

An immune-based risk-stratification system for predicting prognosis in pulmonary sarcomatoid carcinoma (PSC)

Pulmonary sarcomatoid carcinoma (PSC) is an uncommon subtype of lung cancer, and immune checkpoint blockade promises in clinical benefit. However, virtually nothing is known about the expression of common immune checkpoints in PSC. Here, we performed immunohistochemistry (IHC) to detect nine immune-related proteins in 97 PSC patients. Based on the univariable Cox regression, random forests were used to establish risk models for OS and DFS. Moreover, we used the GSEA, CIBERSORT, and ImmuCellAI to analyze the enriched pathways and microenvironment. Univariable analysis revealed that CD4 (P = 0.008), programmed cell death protein 1 (PD-1; P = 0.003), galectin-9 (Gal-9) on tumor cells (TCs; P = 0.021) were independent for DFS, while CD4 (P = 0.020), PD-1 (P = 0.004), Gal-9 (P = 0.033), and HLA on TILs (P = 0.031) were significant for OS. Meanwhile, the expression level of CD8 played a marginable role in DFS (P = 0.061), limited by the number of patients. The combination of Gal-9 on TC with CD4 and PD-1 on TILs demonstrated the most accurate prediction for DFS (AUC: 0.636-0.791, F1-score: 0.635–0.799), and a dramatic improvement to TNM-stage (P < 0.001 for F1-score of 1-y, 3-y, and 5-yDFS). A similar finding was also observed in the predictive ability of CD4 for OS (AUC: 0.602-0.678, F1-score: 0.635–0.679). CD4 was negatively associated with the infiltration of neutrophils (P = 0.015). PDCD1 (coding gene of PD-1) was positively correlated to the number of exhausted T cells (Texs; P = 0.020) and induced regulatory T cells (iTregs; P = 0.021), and LGALS9 (coding gene of Gal-9) was positively related to the level of dendritic cells (DCs; P = 0.021). Further, a higher combinational level of CD4, PDCD1 on TILs, and LAGLS9 on TCs were proved to be infiltrated with more M1-type macrophages (P < 0.05). We confirmed the expression status of nine immune-related proteins and established a TNM-Immune system for OS and DFS in PSC to assist clinical risk-stratification.