Diagnostic criteria and evolving molecular characterisation of pulmonary neuroendocrine carcinomas.

Neuroendocrine carcinomas of the lung are currently classified into two categories: small-cell lung carcinoma and large-cell neuroendocrine carcinoma. Diagnostic criteria for small-cell and large-cell neuroendocrine carcinoma are based solely on tumour morphology; however, overlap in histologic and immunophenotypic features between the two types of carcinomas can potentially make their classification challenging. Accurate diagnosis of pulmonary neuroendocrine carcinomas is paramount for patient management, as clinical course and treatment differ between small-cell and large-cell neuroendocrine carcinoma. Molecular-genetic, transcriptomic, and proteomic data published over the past decade suggest that small-cell and large-cell neuroendocrine carcinomas are not homogeneous categories but rather comprise multiple groups of distinctive malignancies. Nuances in the susceptibility of small-cell lung carcinoma subtypes to different chemotherapeutic regimens and the discovery of targetable mutations in large-cell neuroendocrine carcinoma suggest that classification and treatment of neuroendocrine carcinomas may be informed by ancillary molecular and protein expression testing going forward. This review summarizes the current diagnostic criteria, prognostic and predictive correlates of classification, and evidence of previously unrecognised subtypes of small-cell and large-cell neuroendocrine carcinoma.

[Clinical and molecular pathological features of bronchopulmonary large cell neuroendocrine carcinoma].

Objective: To investigate the clinical manifestations, imaging, pathological and molecular features of bronchopulmonary large-cell neuroendocrine carcinoma (LCNEC). Methods: The clinical data of 216 LCNEC patients in the First Affiliated Hospital of Zhengzhou University from 2011 to 2021 were analyzed retrospectively. The clinical manifestations, tumor location and size, characteristics of CT images, immunohistochemical and molecular pathological features were analyzed and compared with 115 cases of mixed small cell carcinoma (M-SCLC) diagnosed in the same period. Results: Among the 216 LCNEC patients, there were 190 males and 26 females, with a median age of 65 years. The first symptoms of the patients were mainly cough (106 cases, 49.1%) and bloody sputum (48 cases, 22.2%). The median tumor length were 4.7cm, including 55 cases of nodular type (25.5%) and 161 cases of mass-forming type (74.5%). CT imaging results showed that LCNEC lesions had soft tissue density, and the proportion of slight enhancement lesions was significantly lower than that in M-SCLC group (52.3% vs 74.8%, P<0.001). In contrast, the proportion of necrosis (87.0% vs 58.3%, P<0.001) and calcification (26.9% vs 2.6%, P<0.001) in LCNEC patients was significantly higher than that in M-SCLC group. Immunohistochemical results showed that the positive rate of CK in LCNEC was significantly higher than that in M-SCLC (99.0 % vs 90.5%, P<0.05), while the positive rate of TTF-1 was significantly lower than that in M-SCLC (51.6% vs 67.0%, P<0.05). In LCNEC group, the proportion of patients with Ki-67 positive index between 50% and 80% was significantly higher than that of M-SCLC (41.2% vs 25.2%), while the proportion between 80% and 100% was lower than that of M-SCLC (51.9% vs 72.2%). There was no significant difference in the positive rates of CD56 (91.7% vs 94.6%, P=0.336), Syn (83.8% vs 84.7%, P=0.838) and CgA (54.8% vs 50.0%, P=0.632) in both tumor types. Molecular pathology results showed that frequent mutatios were TP53 (54.5%), RB1 (36.4%), KEAP1 (18.2%), MYC(18.2%), and PTEN (14.3%), and the rate of tumor mutation burden which is more than 25 mutation/Mb was 27.3%. Conclusions: LCNEC lacks specific clinical manifestations. CT imaging is powerful in distinguishing LCNEC from M-SCLC. LCNEC contains a specific mutation spectrum. Pathology combined with immunohistochemical staining is still the gold standard for LCNEC diagnosis, and the differentiation from M-SCLC mainly depends on cell size and nuclear chromatin pattern with light microscopy.

Pulmonary large cell carcinoma with neuroendocrine morphology shows genetic similarity to large cell neuroendocrine carcinoma.

BACKGROUND: Large cell neuroendocrine carcinoma (LCNEC) is a high-grade malignant pulmonary neuroendocrine tumour. The distinction of pulmonary large cell carcinoma (LCC) and LCNEC is based on the presence of neuroendocrine morphology and the expression of at least one neuroendocrine marker in at least 10% of tumour cells in the latter. According to the current classification, LCC with neuroendocrine morphology and without neuroendocrine marker expression is classified as LCC. This subgroup we have named LCNEC-null and aimed to analyze its characteristics. METHODS: 31 surgical samples resected in West China Hospital of Sichuan University between 2017 to 2021 were collected, including 7 traditional LCCs, 11 LCNEC-nulls and 13 LCNECs. Each case was conducted to immunohistochemistry and 425-panel-NGS. RESULTS: Compared to other LCCs, detailed analysis of LCNEC-nulls revealed biological features similar to those of LCNECs, especially for immunohistochemistry and molecular analysis: 1. diffusive, coarse granular and high expression of Pan-CK; 2. rare PD-L1 expression; 3. High rate of p53 expression and Rb deficiency 4. abundant genetic alterations are similar to LCNEC. All characteristics above deviated from traditional LCC, indicating they have the same origin as LCNEC. Furthermore, LCNEC could be genetically divided into two subtypes when we reclassified LCNEC-null as LCNEC, and the mutational type and prognosis differed significantly. CONCLUSIONS: We consider that LCNEC-null should be reclassified as LCNEC based on analysis above. In addition, two genetic types of LCNEC with different prognosis also indicate two mechanism of tumour formation.

Large cell neuroendocrine lung carcinoma: consensus statement from The British Thoracic Oncology Group and the Association of Pulmonary Pathologists.

Over the past 10 years, lung cancer clinical and translational research has been characterised by exponential progress, exemplified by the introduction of molecularly targeted therapies, immunotherapy and chemo-immunotherapy combinations to stage III and IV non-small cell lung cancer. Along with squamous and small cell lung cancers, large cell neuroendocrine carcinoma (LCNEC) now represents an area of unmet need, particularly hampered by the lack of an encompassing pathological definition that can facilitate real-world and clinical trial progress. The steps we have proposed in this article represent an iterative and rational path forward towards clinical breakthroughs that can be modelled on success in other lung cancer pathologies.

Genetic Polymorphisms in Activating Transcription Factor 3 Binding Site and the Prognosis of Early-Stage Non-Small Cell Lung Cancer.

BACKGROUND: Activating transcription factor 3 (ATF3) plays a significant role in cancer development and progression. We investigated the association between variants in expression quantitative trait loci (eQTLs) within ATF3 binding regions and the prognosis of non-small cell lung cancer (NSCLC) after surgery. METHODS: A total of 772 patients with NSCLC who underwent curative surgery were enrolled. Using a public database (http://galaxyproject.org), we selected 104 single nucleotide polymorphisms (SNPs) in eQTLs in the ATF3 binding regions. The association of those SNPs with disease-free survival (DFS) was evaluated. RESULTS: Among those SNPs, HAX1 rs11265425T>G was associated with significantly worse DFS (aHR = 1.30, 95% CI = 1.00-1.69, p = 0.05), and ME3 rs10400291C>A was associated with significantly better DFS (aHR = 0.66, 95% CI = 0.46-0.95, p = 0.03). Regarding HAX1 rs11265425T>G, the significant association remained only in adenocarcinoma, and the association was significant only in squamous cell carcinoma regarding ME3 rs10400291C>A. ChIP-qPCR assays showed that the two variants reside in active enhancers where H3K27Ac and ATF3 binding occurs. Promoter assays showed that rs11265425 G allele had significantly higher HAX1 promoter activity than T allele. HAX1 RNA expression was significantly higher in tumor than in normal lung, and higher in rs11265425 TG+GG genotypes than in TT genotype. Conversely, ME3 expression was significantly lower in tumor than in normal lung, and higher in rs10400291 AA genotype than in CC+CA genotypes. CONCLUSIONS: In conclusion, this study shows that the functional polymorphisms in ATF3 binding sites, HAX1 rs11265425T>G and ME3 rs10400291C>A are associated with the clinical outcomes of patients in surgically resected NSCLC.

miR-31 Displays Subtype Specificity in Lung Cancer.

miRNA rarely possess pan-oncogenic or tumor-suppressive properties. Most miRNAs function under tissue-specific contexts, acting as either tumor suppressors in one tissue, promoting oncogenesis in another, or having no apparent role in the regulation of processes associated with the hallmarks of cancer. What has been less clear is the role of miRNAs within cell types of the same tissue and the ability within each cell type to contribute to oncogenesis. In this study, we characterize the role of one such tissue-specific miRNA, miR-31, recently identified as the most oncogenic miRNA in lung adenocarcinoma, across the histologic spectrum of human lung cancer. Compared with normal lung tissue, miR-31 was overexpressed in patient lung adenocarcinoma, squamous cell carcinoma, and large-cell neuroendocrine carcinoma, but not small-cell carcinoma or carcinoids. miR-31 promoted tumor growth in mice of xenografted human adenocarcinoma and squamous cell carcinoma cell lines, but not in large- or small-cell carcinoma lines. While miR-31 did not promote primary tumor growth of large- and small-cell carcinoma, it did promote spontaneous metastasis. Mechanistically, miR-31 altered distinct cellular signaling programs within each histologic subtype, resulting in distinct phenotypic differences. This is the first report distinguishing diverse functional roles for this miRNA across the spectrum of lung cancers and suggests that miR-31 has broad clinical value in human lung malignancy. SIGNIFICANCE: These findings demonstrate the oncogenic properties of miR-31 in specific subtypes of lung cancer and highlight it as a potential therapeutic target in these subtypes. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/8/1942/F1.large.jpg.

Clinicopathological significance of the expression of PD-L1 in non-small cell lung cancer.

INTRODUCTION: PD1/PD-L1 pathway targeting therapies are nowadays an established treatment option for patients with NSCLC. We assessed whether PD-L1 expression in NSCLC tumor cells was associated with specific clinical features or overall survival using four different clones. METHODS AND RESULTS: A retrospective study included formalin-fixed paraffin embedded (FFPE) surgical tumors from 482 patients. PD-L1 status was assessed with immunohistochemistry in tumor cells on tissue microarrays using clones 28-8, 22C3, SP263 and SP142. Associations with OS were assessed by Kaplan-Meier and multivariate Cox's regression analysis. Patients' median age: 68 years (39-86); histology: adenocarcinoma (AdCa) 61%, squamous-cell carcinoma (SqCC) 33%, and large cell carcinoma (LCC) 6%; p-stage: IA (46%), IB (30%), IIA (10%), IIB (11,4%), IIIA (1,2%), IIIB - IV (0,4%). PD-L1 positivity (≥1%) in NSCLC for clones 28-8, 22C3, SP263, SP142 was 41.5%, 34.2%, 42.7%, 10.4%, respectively (Pearson Chi-square p < 0.0001). PD-L1 expression was correlated with histology, tumor size and grading. Statistically significant association between PD-L1 expression and OS in NSCLC and Non-AdCa was observed with clone SP142 (log-rank p = 0.045 and p = 0.05, respectively). Statistically significant association between PD-L1 expression and OS in LCC was observed with clones 22C3 (log-rank p = 0.009) and SP263 (log-rank p = 0.050). CONCLUSIONS: Overexpression of the PD-L1 clone SP142 was associated with poor overall survival in NSCLC and Non-AdCa. Clones 22C3 and SP263 were associated with poor prognosis in LCC. PD-L1 status might serve as a prognostic marker in NSCLC.

Ki-67 Index of 55% Distinguishes Two Groups of Bronchopulmonary Pure and Composite Large Cell Neuroendocrine Carcinomas with Distinct Prognosis.

BACKGROUND: Little information is available concerning prognostic factors for bronchopulmonary large cell neuroendocrine carcinomas (BP-LCNECs) and even less is known about combined LCNECs (Co-LCNECs). We investigated whether an integrated morphological, immunohistochemical, and molecular approach could be used for their prognostic evaluation. METHODS: Morphological (including combined features), proliferative (mitotic count/Ki-67 index), immunohistochemical (napsin A, p40, TTF-1, CD44, OTP, SSTR2A, SSTR5, mASH1, p53, RB1, and MDM2), and genomic (TP53, RB1, ATM, JAK2, KRAS, and STK11) findings were analyzed in BP-LCNECs from 5 Italian centers, and correlated with overall survival (OS). The Ki-67 index was expressed as the percentage of positive cells in hot spots as indicated in the WHO 2019 Digestive System Tumors and, for Co-LCNECs, the Ki-67 index was evaluated only in the LCNEC component. RESULTS: A total of 111 LCNECs were distinguished into 70 pure LCNECs, 35 Co-LCNECs (27 with adenocarcinoma [ADC] and 8 with squamous cell carcinoma [SqCC]), and 6 LCNECs with only napsin A immunoreactivity. The Ki-67 index cutoff at 55% evaluated in the neuroendocrine component was the most powerful predictor of OS (log-rank p = 0.0001) in all LCNECs; 34 cases had a Ki-67 index <55% (LCNEC-A) and 77 had a Ki-67 index ≥55% (LCNEC-B). Statistically significant differences in OS (log-rank p = 0.0001) were also observed between pure and Co-LCNECs. A significant difference in OS was found between pure LCNECs-A and Co-LCNECs-A (p < 0.05) but not between pure LCNECs-B and Co-LCNECs-B. Co-LCNEC-ADC and LCNEC napsin A+ cases had longer OS than pure LCNEC and Co-LCNEC-SqCC cases (log-rank p = 0.0001). On multivariable analysis, tumor location, pure versus combined features, and napsin A, but no single gene mutation, were significantly associated with OS after adjustment for Ki-67 index and study center (p < 0.05). CONCLUSIONS: The Ki-67 proliferation index and the morphological characterization of combined features in LCNECs seem to be important tools for predicting clinical outcome in BP-LCNECs.

TTF-1 and c-MYC-defined Phenotypes of Large Cell Neuroendocrine Carcinoma and Delta-like Protein 3 Expression for Treatment Selection.

The standard treatment regimen has not yet been established for advanced pulmonary large cell neuroendocrine carcinoma (LCNEC) because of its rarity. LCNEC can be subdivided into 2 mutually exclusive molecular subgroups: STK11/KEAP1 and TP53 mutated with high neuroendocrine expression and transcriptional profile of ASCL1high/DLL3high/NOTCHlow (non-small cell lung carcinoma, NSCLC-like) or RB1 and TP53 mutated with reduced neuroendocrine markers and transcriptional pattern of ASCL1low/DLL3low/NOTCHhigh (small cell lung cancer, SCLC-like). Model-based clustering shows that SCLC has subdivided into 2 major proteomic subsets defined by either TTF-1high/c-MYClow or TTF-1low/c-MYChigh, which may correspond to 2 mutually exclusive molecular subgroups: NSCLC-like or SCLC-like, respectively. We herein investigated whether TTF-1 and c-MYC could be applied to LCNEC to identify distinct subsets immunohistochemically and assessed DLL3 expression in these subsets. The protein expression profile may be useful to select patients for potential efficacy of targeted therapies including aurora kinase inhibitors for MYC alterations or anti-DLL3 antibody-drug conjugates. TTF-1 and c-MYC expression was mutually exclusive in 25 of 27 (93%) cases; TTF-1+/c-MYC- in 10, TTF-1-/c-MYC+ in 15, and TTF-1+/c-MYC+ in 2. DLL3 expression was seen in 15 of 27 cases (56%). All 12 TTF-1+ LCNEC cases were positive for DLL3. Three of 15 (20%) TTF-1-/c-MYC+ cases showed DLL3 positivity. LCNEC could be separated into 2 subsets proteomically defined by TTF-1 and c-MYC expression, which may be suitable to guide treatment selection including aurora kinase inhibitors for c-MYC+ cases. TTF-1 positivity can serve as a surrogate marker for DLL3, but caution is necessary as 20% of TTF-1- cases showed DLL3 positivity.

DLL3 expression is a predictive marker of sensitivity to adjuvant chemotherapy for pulmonary LCNEC.

BACKGROUND: The mammalian Notch family ligands delta-like 3 (DLL3) is reported to be a potential therapeutic target for large cell neuroendocrine carcinomas (LCNEC). The effect of DLL3 expression on LCNEC prognosis has not yet been elucidated. METHODS: We reviewed the medical records of 70 LCNEC patients undergoing surgical resection between 2001 and 2015 using a prospectively maintained database. We performed immunohistochemistry for DLL3 and investigated the correlation between the sensitivity of LCNEC to platinum-based adjuvant chemotherapy. RESULTS: DLL3 expression was positive in 26 (37.1%) LCNEC patients. A total of 23 patients (32.9%) received platinum-based adjuvant chemotherapy. Among patients with DLL3 expression-positive tumors, no difference was found in the five-year overall survival (OS) or recurrence-free survival (RFS) between patients with and without adjuvant chemotherapy (surgery + chemotherapy vs. surgery alone, five-year OS: 58.3% vs. 35.7% P = 0.36, five-year RFS: 41.7% vs. 35.7% P = 0.74). In contrast, among patients with DLL3-negative tumors, significantly greater five-year OS and RFS rates were observed for patients with adjuvant chemotherapy than for those without it (surgery + chemotherapy vs. surgery alone: five-year OS: 90.0% vs. 26.9% P<0.01, five-year RFS: 80.0% vs. 21.7% P < 0.01). A multivariate analysis for the RFS revealed that adjuvant chemotherapy was a significant independent prognostic factor among patients with DLL3-negative tumors (hazard ratio [HR]: 0.05, 95% confidence interval [CI]: 0.01-0.41, P < 0.01), although it was not a factor among patients with DLL3-positive tumors (HR: 0.73, 95% CI: 0.23-2.27, P = 0.58). CONCLUSIONS: Our results revealed that DLL3 is a predictive marker of sensitivity to platinum-based adjuvant chemotherapy for LCNEC. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: DLL3 was a predictive marker of sensitivity to platinum-based adjuvant chemotherapy for LCNEC. Among patients with DLL3 expression-negative LCNEC, platinum-based adjuvant chemotherapy significantly improved the OS and RFS, although it did not do so among patients with DLL3 expression-positive LCNEC. WHAT THIS STUDY ADDS: Our results suggest that DLL3 expression-positive LCNEC may be better treated with other types of adjuvant chemotherapy, such as the anti-DLL3 therapies if these effects are confirmed by ongoing clinical research.

Immunohistological expression of oestrogen receptor, progesterone receptor, mammaglobin, human epidermal growth factor receptor 2 and GATA-binding protein 3 in non-small-cell lung cancer.

AIMS: Non-small-cell lung cancer (NSCLC) and breast cancer are common entities. Staining for oestrogen receptor (ER), progesterone receptor (PgR), mammaglobin (MAMG) and GATA-binding protein 3 (GATA3) is frequently performed to confirm a mammary origin in the appropriate diagnostic setting. However, comprehensive data on the immunohistological expression of these markers in NSCLC are limited. Therefore, the aim of this study was to analyse a large cohort of NSCLCs and correlate the staining results with clinicopathological variables. METHODS AND RESULTS: A tissue microarray was stained for ER, PgR, MAMG, human epidermal growth factor receptor 2 (HER2), and GATA3, and included 636 adenocarcinomas (ADCs), 536 squamous cell carcinomas (SqCCs), 65 large-cell-carcinomas, 34 pleomorphic carcinomas, and 20 large-cell neuroendocrine carcinomas. HER2 status was determined for immunohistochemically positive cases with chromogenic in-situ hybridisation. Markers with a proportion of ≥5% positive cases in ADC and SqCC were considered for survival analysis. Among ADCs, 62 (10%), 17 (3%), one (<1%), seven (1%), and 49 (8%) cases were positive for ER, PgR, MAMG, HER2, and GATA3, respectively. Among SqCCs, 10 (2%), 14 (3%), two (<1%) and 109 (20%) cases were positive for ER, PgR, HER2, and GATA3, but none of the samples showed positivity for MAMG. ER positivity was associated with ADC, female sex, smaller tumour size, and lower clinical stage. None of the markers had an impact on survival. CONCLUSION: We report on ER, PgR, MAMG, HER2 and GATA3 expression in a large cohort of NSCLCs. Interpretation of these markers in the differential diagnostic setting should be based on a multimarker panel.

Osimertinib, a third-generation EGFR tyrosine kinase inhibitor: A retrospective multicenter study of its real-world efficacy and safety in advanced/recurrent non-small cell lung carcinoma.

BACKGROUND: Osimertinib is recommended for T790M mutation-positive advanced non-small cell lung cancer (NSCLC) resistant to first- and second-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs). Recently, some reports exist on the real-world use of osimertinib; however, reports involving third/later-line use are few. Hence, this study was conducted to evaluate the efficacy and safety of osimertinib used in various treatment lines for T790M-positive NSCLC patients. METHODS: This retrospective, observational, multicenter study included T790M-positive advanced/recurrent NSCLC patients treated with osimertinib from May 2016 to March 2018. The clinical characteristics, efficacy, and adverse events were retrospectively investigated. The Kaplan-Meier method was used to analyze progression-free survival (PFS) and overall survival (OS). PFS-associated clinical characteristics were evaluated using the Cox proportional hazards model. RESULTS: The objective response rate (ORR) and disease control rate (DCR) were 60.7% and 91.1%, respectively; the median PFS was 11.0 months. There were no significant differences in the median PFS for patients treated with osimertinib as second-line and third-/later-line (14.5 vs. 11.0 months respectively, P = 0.327). Analysis using the Cox proportional hazards model for clinical features affecting PFS also revealed no significant factors. Adverse events of grade ≥ 3 were reported in 15 patients (26.8%); the most common were anemia (n = 3) and cutaneous toxicity (n = 3). Grade 4 neutropenia was observed in one patient; any-grade pneumonitis was observed in six patients (10.7%), including one with grade 3 pneumonitis. CONCLUSIONS: Osimertinib demonstrated efficacy even when administered as third-/later-line treatment to NSCLC patients. Osimertinib-related pneumonitis was observed more frequently than previously reported. KEY POINTS: Significant findings of the study Osimertinib shows efficacy even as later-line treatment in T790M mutation-positive NSCLC patients previously treated with EGFR-TKIs. However, the incidence of ≥ grade 3 adverse events, especially pneumonitis, was higher than that previously reported by other studies. What this study adds Osimertinib was approved for previously EGFR-TKI-treated EGFR T790M-positive NSCLC. With the increasing frequency of its use as first-line treatment, this study provides valuable evidence for the efficacy and safety of osimertinib for previously EGFR-TKI-treated NSCLC.

Case Report: Therapeutic Response to Chemo-Immunotherapy in an Advanced Large Cell Lung Carcinoma Patient With Low Values of Multiple Predictive Biomarkers.

Immune checkpoint inhibitors have revolutionized the treatments of lung cancers, and multiple predictive biomarkers alone or in combination help clinicians with the appropriate therapeutic selections. Recently, chemo-immunotherapy has been recommended for treating advanced non-small cell lung cancers in patients without driver mutations. However, the clinical relevance of predictive biomarkers and the treatment efficacy of chemo-immunotherapy in large cell lung carcinoma (LCLC) remain unclear. Here, we reported a rare case of LCLC with none driver gene mutations and low values of multiple predictive biomarkers. These biomarkers included a low PD-L1 expression of 5-10%, a low tumor mutational burden (TMB) of 2.5 muts/mb, a low CD8(+) tumor-infiltrating lymphocyte density of 147.91 psc/mm². After one-cycle chemotherapy, the patient progressed rapidly and then was switched to pembrolizumab combining paclitaxel plus cisplatin. Interestingly, he achieved a partial response after two cycles of chemo-immunotherapy, showing multiple lymph nodes obviously shrunk on CT scan, and other clinical symptoms were relieved when compared with the baseline findings. After five cycles of chemo-immunotherapy, this advanced patient still benefited and was changed to maintenance immunotherapy monotherapy. This case suggests that chemo-immunotherapy may provide an effective therapeutic option for those LCLC patients with low values of multiple predictive biomarkers, particularly for those who progressed from first-line classical treatments.

The diagnostic utility of zinc E-box 1 (ZEB1) transcription factor for identification of pulmonary sarcomatoid carcinoma in cytologic and surgical specimens.

OBJECTIVE: Although uncommon, pulmonary sarcomatoid carcinoma carries a worse prognosis due to poor chemotherapeutic response. Currently, a histologic spindle and/or giant cell component indicates sarcomatoid differentiation, with zinc E-box binding homeobox 1 (ZEB1) implicated in promoting epithelial-mesenchymal transition. However, diagnostic use of ZEB1 in limited specimens, including cell block (CB) preparations, remains unclear. MATERIALS AND METHODS: Pulmonary sarcomatoid (SARC, n = 15), typical (TC, n = 10) and atypical carcinoid (AC, n = 10), small cell (SCLC, n = 8) and large cell neuroendocrine carcinoma (LCNEC, n = 9), squamous cell carcinoma (SQ, n = 7), and adenocarcinoma (ADC, n = 7) CBs along with 69 SARCs, 20 TCs, 21 ACs, 9 SCLCs, 10 LCNECs, 71 SQs, 402 ADCs, 16 large cell carcinoma (LCC) and 17 other thoracic tumor (OT) surgical specimens between 2007 and 2018 were retrieved. ZEB1 (Sigma Aldrich, St. Louis, Mo and Novus Biological, Centennial, Colo) immunohistochemistry was graded 1+ to 3+, with ≥1+ and >5% staining considered positive. RESULTS: Nuclear ZEB1 was seen in 80% SARC (12/15), 0% TC (0/10), 0% AC (0/10), 12.5% SCLC (1/8) and 11.1% LCNEC (1/9), 0% SQ (0/7), and 0% ADC (0/7) CBs. In surgical specimens, 75.4% SARCs (52/69), 0% TCs (0/20), 0% ACs (0/21), 11.1% SCLCs (1/9), 30% LCNECs (3/10), 0% SQs (0/71), 0.2% ADCs (1/402), 12.5% LCCs (2/16), and 11.8% OTs (2/17) demonstrated ZEB1. ZEB1 sensitivity and specificity in cytology and surgical specimens were 80% and 96.1%, and 75.4% and 98.1%, respectively. CONCLUSIONS: ZEB1 is sensitive and highly specific for pulmonary sarcomatoid carcinoma in limited cytologic and surgical specimens. Diagnostic pitfalls include high-grade neuroendocrine tumors and large cell carcinoma, which are resolvable by morphologic considerations.

DLL3 expression in large cell neuroendocrine carcinoma (LCNEC) and association with molecular subtypes and neuroendocrine profile.

OBJECTIVES: For stage IV pulmonary large cell neuroendocrine carcinoma (LCNEC), the only therapeutic option is palliative chemotherapy. DLL3 is a new therapeutic target, which seems to be often expressed in SCLC and LCNEC. It has recently been reported that DLL3 mRNA expression is particularly upregulated in the LCNEC subgroup with STK11/KEAP1 and TP53 co-mutations, in contrast to lower expression levels in RB1 and TP53 co-mutated LCNEC. Our aim was to investigate DLL3 protein expression in stage IV LCNEC and correlate data with mutational profiles (i.e.STK11/KEAP1/RB1), immunostaining results (pRb, NE markers) and clinical characteristics. MATERIALS AND METHODS: Immunohistochemical analysis for DLL3 (SC16.65) and ASCL1 (SC72.201) was performed on 94 and 51 FFPE tissue sections, respectively, of pathologically reviewed stage IV LCNEC. DLL3 and ASCL1 were scored positive if ≥1% of the tumor cells showed cytoplasmic/membranous or dotlike (DLL3) or nuclear (ASCL1) immunostaining. Data were correlated with available sequencing (TP53, RB1, STK11, KEAP1), immunostaining (pRb, NE markers) and clinical data. RESULTS: DLL3 was expressed in 70/94 (74%) LCNEC, 56 (80%) of which showed cytoplasmic/membranous staining. Median H-score was 55 (interquartile range 0-160). DLL3 staining was not different in pRb immunohistochemistry negative and positive patients (DLL3+ in 53/70 (76%) vs. 14/21 (67%), p = 0.409) or RB1 mutated and wildtype patients (DLL3+ in 27/34 (79%) vs. 23/33 (70%), p = 0.361). Nevertheless, 6/6 (100%) STK11 mutated, 10/11 (91%) KEAP1 mutated and 9/9 (100%) TP53 wildtype tumors were DLL3+ . Furthermore, DLL3 expression was associated with expression of ASCL1 and at least 2 out of 3 neuroendocrine markers. CONCLUSION: The high percentage (74%) of DLL3 expression in stage IV LCNEC denotes the potential of DLL3 targeted therapy in this patient group.

Biliary tract large cell neuroendocrine carcinoma: current evidence.

BACKGROUND: Primary neuroendocrine carcinomas of the gallbladder and biliary tract are rare, with pure large cell neuroendocrine carcinomas (LCNEC) being exceedingly rare and with a particularly poor prognosis. METHODS: We performed a review of published data on biliary tract large cell neuroendocrine carcinomas in PubMed. RESULTS: Preliminary search revealed over 2000 results but we found only 12 cases of pure large cell neuroendocrine carcinomas of biliary tract noted in literature to date. Because it commonly presents with non-specific symptoms of abdominal pain and jaundice, diagnosis is made after resection with histo-pathological and immunohistochemical analysis. These cancers are particularly aggressive with high recurrence rates, most often presenting with metastasis to regional lymph nodes and/or the liver resulting in a poor prognosis. Overall, complete surgical excision with systemic chemotherapy is the treatment mainstay. If the cancer is unresectable due to multiple metastases, medical management with systemic chemotherapy is the primary treatment modality. CONCLUSION: The prognosis of hepatobiliary LCNEC remains poor with median survival of only 11 months from initial diagnosis. Studies focusing on high grade neuroendocrine carcinoma are needed to enhance our understanding of biology and therapeutics in this rare but aggressive cancer.

Neuroendocrine marker staining pattern categorization of small-sized pulmonary large cell neuroendocrine carcinoma.

BACKGROUND: The aim of this study was to identify subgroups with good or bad prognosis in patients with pulmonary large cell neuroendocrine carcinoma (LCNEC) based on immunostaining patterns with neuroendocrine markers and compare them with small cell lung carcinoma (SCLC). METHODS: From January 2001 to December 2017, of all patients with resected LCNEC and SCLC, we selected patients whose pathological tumor sizes were ≤30 mm in diameter (defined as small-sized tumors) and who underwent complete resection with lymphadenectomy. We classified patients with small-sized LCNEC (sLCNEC) into two subgroups based on immunostaining patterns with three neuroendocrine markers (chromogranin A, synaptophysin, and NCAM) and compared them to small-sized SCLC (sSCLC). RESULTS: A total of 48 patients with sLCNEC and 39 patients with sSCLC were enrolled. Of 48 patients with sLCNEC, 21 were categorized as the small-sized triple-positive group (sTP), whose patients were positive for the three neuroendocrine markers, and 27 patients were categorized as the small-sized nontriple-positive group (sNTP), whose patients were not positive for all three neuroendocrine markers. The percentage of lymph node metastasis was significantly lower in sNTP than in sTP and sSCLC. There was no significant difference in overall survival, but recurrence-free survival (RFS) and tumor-specific survival (TSS) were significantly poorer in sTP and sSCLC than in sNTP. Multivariate analysis revealed sTP and sSCLC were independent prognostic factors for poorer RFS and TSS than those of sNTP. CONCLUSIONS: The sNTP subgroup had a good prognosis and the sTP subgroup a poor prognosis. There were some similarities in clinicopathological features between sTP and sSCLC.

Expression Of Intracellular Components of the NF-κB Alternative Pathway (NF-κB2, RelB, NIK and Bcl3) is Associated With Clinical Outcome of NSCLC Patients.

A growing number of studies has shed light on the role of the NF-κΒ in non-small-cell lung cancer (NSCLC). To address the significance of major effectors of the NF-κΒ alternative pathway, we investigated the relationship between NF-κΒ2, RelB, NIK and Bcl3 expression (mRNA and protein) and the clinical outcome of NSCLC patients. NF-κΒ2, RelB, NIK and Bcl3 protein expression levels were assessed by immunohistochemistry in tissue samples from 151 NSCLC patients who had curative resection. mRNA levels were also evaluated in 69 patients using quantitative real-time PCR. Although all studied proteins were overexpressed in NSCLC (P < 0.001 for all), only RelB mRNA levels were strongly increased in cancerous specimens compared to tumor-adjacent non-neoplastic tissues (P = 0.009). Moreover, NF-κB2, RelB and Bcl3 expression was associated with overall survival (OS). In particular, cytoplasmic and mRNA expression of RelB was related to 5-year OS (P = 0.014 and P = 0.006, respectively). Multivariate analysis also showed that Bcl3 expression (nuclear and cytoplasmic) was associated with increased 5-year OS (P = 0.002 and P = 0.036, respectively). In addition, higher Bcl3 mRNA levels were associated with inferior OS in stages I & II and improved OS in stages III and IV after 5-year follow-up (P = 0.004 and P = 0.001, respectively). Furthermore, stage I patients with lower NF-κB2 mRNA levels had better 5-year survival in univariate and multivariate analysis (P = 0.031 and P = 0.028, respectively). Interestingly, RelB expression (cytoplasmic and mRNA) was inversely associated with relapse rates (P = 0.027 and P = 0.015, respectively), while low NIK cytoplasmic expression was associated with lower relapse rates (P = 0.019). Cytoplasmic NIK expression as well as NF-κB2/ Bcl3 detection was associated with lymph node infiltration (P = 0.039 and P = 0.014, respectively). The present study confirms the deregulation of the NF-κB alternative pathway in NSCLC and also demonstrates the importance of this pathway in prognosis, recurrence and infiltration of regional lymph nodes.

Therapeutic Targeting of Aldolase A Interactions Inhibits Lung Cancer Metastasis and Prolongs Survival.

Cancer metabolic reprogramming promotes tumorigenesis and metastasis; however, the underlying molecular mechanisms are still being uncovered. In this study, we show that the glycolytic enzyme aldolase A (ALDOA) is a key enzyme involved in lung cancer metabolic reprogramming and metastasis. Overexpression of ALDOA increased migration and invasion of lung cancer cell lines in vitro and formation of metastatic lung cancer foci in vivo. ALDOA promoted metastasis independent of its enzymatic activity. Immunoprecipitation and proteomic analyses revealed γ-actin binds to ALDOA; blocking this interaction using specific peptides decreased metastasis both in vitro and in vivo. Screening of clinically available drugs based on the crystal structure of ALDOA identified raltegravir, an antiretroviral agent that targets HIV integrase, as a pharmacologic inhibitor of ALDOA-γ-actin binding that produced antimetastatic and survival benefits in a xenograft model with no significant toxicity. In summary, ALDOA promotes lung cancer metastasis by interacting with γ-actin. Targeting this interaction provides a new therapeutic strategy to treat lung cancer metastasis. SIGNIFICANCE: This study demonstrates the role of aldolase A and its interaction with γ-actin in the metastasis of non-small lung cancer and that blocking this interaction could be an effective cancer treatment.

Identification of key modules and hub genes for small-cell lung carcinoma and large-cell neuroendocrine lung carcinoma by weighted gene co-expression network analysis of clinical tissue-proteomes.

Small-cell lung carcinoma (SCLC) and large-cell neuroendocrine lung carcinoma (LCNEC) are high-grade lung neuroendocrine tumors (NET). However, comparative protein expression within SCLC and LCNEC remains unclear. Here, protein expression profiles were obtained via mass spectrometry-based proteomic analysis. Weighted gene co-expression network analysis (WGCNA) identified co-expressed modules and hub genes. Of 34 identified modules, six were significant and selected for protein-protein interaction (PPI) network analysis and pathway enrichment. Within the six modules, the activation of cellular processes and complexes, such as alternative mRNA splicing, translation initiation, nucleosome remodeling and deacetylase (NuRD) complex, SWItch/Sucrose Non-Fermentable (SWI/SNF) superfamily-type complex, chromatin remodeling pathway, and mRNA metabolic processes, were significant to SCLC. Modules enriched in processes, including signal recognition particle (SRP)-dependent co-translational protein targeting to membrane, nuclear-transcribed mRNA catabolic process of nonsense-mediated decay (NMD), and cellular macromolecule catabolic process, were characteristically activated in LCNEC. Novel high-degree hub genes were identified for each module. Master and upstream regulators were predicted via causal network analysis. This study provides an understanding of the molecular differences in tumorigenesis and malignancy between SCLC and LCNEC and may help identify potential therapeutic targets.