Pulmonary Neuroendocrine Carcinoma Research Articles

EP.13D.11 Proportion and Characterization of Pulmonary Neuroendocrine Carcinoma via Synaptopysin IHC

EP.13D.11 Proportion and Characterization of Pulmonary Neuroendocrine Carcinoma via Synaptopysin IHC

Prognostic impact of interstitial lung disease on pulmonary high-grade neuroendocrine carcinoma

Pulmonary high-grade neuroendocrine carcinomas (HGNECs) have poor prognoses and require multimodal treatment, and interstitial lung disease (ILD) restricts sufficient treatment of patients with lung cancer. We aimed to clarify ILD’s prognostic impact on pulmonary HGNEC, which has previously gone unreported. We retrospectively analyzed 53 patients with HGNEC who underwent resections at our department between 2006 and 2021 and evaluated the clinicopathological prognostic features, including ILD. The patients’ mean age was 70 years; 46 (87%) were male, and all were smokers. Large-cell neuroendocrine and small-cell lung carcinomas were diagnosed in 36 (68%) and 17 (32%) patients, respectively. The pathological stages were stage I, II, and III in 31 (58%), 11 (21%), and 11 (21%) patients, respectively. Nine patients (17%) had ILD, which was a significant overall survival prognostic factor in a multivariate Cox proportional hazards regression analysis (p = 0.048), along with lymph node metastasis (p = 0.004) and non-administration of platinum-based adjuvant chemotherapy (p = 0.003). The 5 year survival rate of the ILD patients was 0%, significantly worse than that of patients without ILD (58.7%; p = 0.003). Patients with HGNEC and ILD had a poor prognosis owing to adjuvant therapy’s limited availability for recurrence and the development of acute exacerbations associated with ILD.

The prognostic analysis and a machine-learning based disease-specific survival state model in pulmonary large-cell neuroendocrine carcinomas.

Pulmonary large-cell neuroendocrine carcinoma (PLCNEC) is a rare and highly malignant lung cancer. Due to the paucity of data from clinical studies, its clinical characteristics and treatment remain controversial. The present study explored factors influencing the prognosis and survival outcomes of patients with PLCNEC and developed a dependable prognostic model using machine learning. The clinical data of PLCNEC patients were extracted from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2020. A total of 2,897 PLCNEC patients were enrolled and univariate and multivariate Cox regression analyses were performed to explore independent prognostic factors for disease-specific survival (DSS). Ten machine learning algorithms were utilized to predict the 2-year survival. The clinicopathological data collected from The First Affiliated Hospital of Sun Yat-sen University between 2010 and 2022 were used to test the trained machine. Sex [hazard ratio (HR) 1.168, 95% confidence interval (CI): 1.063-1.284], age (HR 1.262, 95% CI: 1.144-1.391), surgery (HR 0.481, 95% CI: 0.413-0.559), chemotherapy (HR 0.450, 95% CI: 0.404-0.501), bone metastasis (HR 1.284, 95% CI: 1.124-1.466), brain metastasis (HR 1.167, 95% CI: 1.023-1.331), liver metastasis (HR 1.223, 95% CI: 1.069-1.399), American Joint Committee on Cancer-Node (AJCC-N), and tumor stage were independent prognostic factors. The gradient boosting decision tree (GBDT) performed better than other models, with an F1-score of 0.791 and an area under the curve of 0.831. Male, age ≥65 years, distant metastasis to the bone, liver, and brain are associated with a worse prognosis in PLCNEC patients, while surgery and chemotherapy are associated with improved prognosis. GBDT showed promising performance in predicting 2-year survival, which can serve as a valuable reference for clinical diagnosis and treatment of PLCNEC.

Prognostic factors and nomogram for pulmonary resected high-grade neuroendocrine carcinomas: a 20-year single institutional real-world experience

BackgroundPulmonary high-grade neuroendocrine carcinomas(pHGNEC) encompassing small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC) are clinically aggressive tumors with poor prognosis. The role of surgery and prognostic factors guiding management remain unclear. We aimed to analyze prognosis following resection and identify predictive variables.MethodsThis retrospective study analyzed 259 patients undergoing pHGNEC resection from 2001–2023. Overall survival (OS) and disease-free survival (DFS) were evaluated using Kaplan–Meier curves. Prognostic factors were assessed with Cox regression and visualized using nomogram tools.ResultsMinimally invasive surgery was associated with better OS (p = 0.001) and DFS (p = 0.001). Higher T stage predicted worse OS (T2 p = 0.044, T4 p = 0.007) and DFS (T2 p = 0.020, T4 p = 0.004). Advanced TNM stage III (OS p = 0.018; DFS p = 0.015) and IV (OS p < 0.001; DFS p < 0.001) also correlated with poorer prognosis. In the SCLC subgroup, elevated preoperative CEA independently predicted worse OS (p = 0.012) and DFS (p = 0.004). T4 disease (OS p < 0.001; DFS p = 0.002) and advanced TNM staging (stage III OS p = 0.043; DFS p = 0.045; stage IV OS p < 0.001, DFS p < 0.001) were associated with worse outcomes. In LCNEC patients, VATS resection improved OS (p = 0.048) and DFS (p = 0.027) despite conversion. Prior malignancy predicted worse OS (p < 0.001). Advanced TNM disease (stage III OS p = 0.047; stage IV OS p = 0.003, DFS p = 0.005) were also negative prognostic factors. The prognostic nomogram incorporating above variables effectively stratified risk. Calibration plots revealed good correlation between predicted and actual survival.ConclusionsWe identified minimally invasive surgery, early TNM stage, younger age, and normal preoperative CEA as positive prognostic factors following pHGNEC resection. Our study provides an applicable prognostic nomogram to facilitate personalized pHGNEC management.

Metastatic pulmonary neuroendocrine carcinoma associated with AVP deficiency and panhypopituitarism due to a hypothalamic metastasis

Metastatic pulmonary neuroendocrine carcinoma associated with AVP deficiency and panhypopituitarism due to a hypothalamic metastasis

Neoadjuvant immunochemotherapy for pulmonary large-cell neuroendocrine carcinoma: case report

BackgroundPulmonary large-cell neuroendocrine carcinoma (pLCNEC) represents a rare malignancy characterized by its aggressive behavior and a notably high recurrence rate. Remarkably, there is currently no established standard treatment protocol for this condition.Case descriptionIn this report, we present an intriguing case of pLCNEC diagnosed at clinical-stage IIB. This case involves a 64-year-old man with a smoking history spanning four decades. In our approach, we initiated a course of neoadjuvant chemotherapy in combination with pembrolizumab, administered for two cycles prior to surgical resection. This innovative treatment strategy resulted in a significant pathological response, culminating in a major pathological remission (MPR). As of the time of composing this report, the patient has been diligently monitored for 39 months post-surgery, exhibiting no indications of recurrence, and has demonstrated exceptional tolerance to the entire treatment regimen.ConclusionsWe have first reported a clinically successful case of neoadjuvant combination chemotherapy with pembrolizumab in the treatment of pLCNEC. This case offers promising clinical insights and suggests that this therapeutic approach could be a viable option for managing pLCNEC.

Patient-derived tumoroid models of pulmonary large-cell neuroendocrine carcinoma: a promising tool for personalized medicine and developing novel therapeutic strategies

Pulmonary large-cell neuroendocrine carcinoma (LCNEC), a disease with poor prognosis, is classified as pulmonary high-grade neuroendocrine carcinoma, along with small-cell lung cancer. However, given its infrequent occurrence, only a limited number of preclinical models have been established. Here, we established three LCNEC tumoroids for long-term culture. Whole-exome sequencing revealed that these tumoroids inherited genetic mutations from their parental tumors; two were classified as small-cell carcinoma (S-LCNEC) and one as non-small cell carcinoma (N-LCNEC). Xenografts from these tumoroids in immunodeficient mice mimicked the pathology of the parent LCNEC, and one reproduced the mixed-tissue types of combined LCNEC with a component of adenocarcinoma. Drug sensitivity tests using these LCNEC tumoroids enabled the evaluation of therapeutic agent efficacy. Based on translational research, we found that a CDK4/6 inhibitor might be effective for N-LCNEC and that Aurora A kinase inhibitors might be suitable for S-LCNEC or LCNEC with MYC amplification. These results highlight the value of preclinical tumoroid models in understanding the pathogenesis of rare cancers and developing treatments. LCNEC showed a high success rate in tumoroid establishment, indicating its potential application in personalized medicine.

Treatment of poorly differentiated neuroendocrine carcinomas of rectum and anus with chemoradiotherapy: a single-centre evaluation

PurposePoorly differentiated neuroendocrine carcinoma (PDNEC) of the rectum and anus is a rare disease exhibiting aggressive biological behaviour, even if diagnosed early. Currently, there are no agreed standard treatment approaches and management of locally advanced (LA) and metastatic PDNEC usually follows treatments used in pulmonary neuroendocrine carcinomas because of the similarities with small cell lung cancer. The role of surgery in PDNEC is still debated and the benefit of chemoradiotherapy (CRT) is unknown. This report summarises the experiences of CRT application in anorectal PDNEC in a single Danish institution.MethodsAll patients with PDNEC treated with concomitant CRT between May 2019 and January 2021 at a University hospital in Denmark were evaluated. Demographics, treatment and survival outcomes were collected and analysed.ResultsSix patients were identified. Five patients received radiotherapy with 50.4 Gy/28 fractions, and four were eligible for curative resection after the CRT. Distant metastasis was observed in four patients at diagnosis. Two patients with synchronous liver metastases were treated with RFA, and one received a liver resection. The treatment was well tolerated with limited side effects. The median follow-up time was 17 months (range 10–36 months), and the median duration of response was 11.2 months (range 8.1 to 24.2 months). One patient achieved a complete response.ConclusionA multimodal treatment approach with CRT in advanced stages of PDNEC in a highly selected patient group is well tolerated and with a high chance of achieving local control and, combined with surgery, even complete response in a single case.

A prognostic nomogram based on least absolute shrinkage and selection operator Cox regression in patients with pulmonary large-cell neuroendocrine carcinoma.

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a rare subtype of breast cancer with a poor prognosis. Despite its rarity, it is important to gain a better understanding of the epidemiological, clinical, and prognostic features of pulmonary LCNEC. The purpose of this study was to design, construct, and validate a new nomogram for predicting overall survival (OS) in patients with pulmonary LCNEC. In total, the data of 1,864 LCNEC patients were extracted from the Surveillance, Epidemiology, and End Results (SEER) database, which is maintained by the National Cancer Institute in the United States and serves as a comprehensive source of cancer-related information. Of these patients, 556 served as the validation group and 1,308 served as the training cohort. We constructed a new nomogram with the training cohort that included the independent factors for OS as identified by least absolute shrinkage and selection operator Cox regression. Five independent factors were ultimately selected by the stepwise regression. Every factor of the Cox regression was included in the nomogram. Analyses of the calibration curve, decision curve, area under the curve, and concordance index (C-index) values were performed to assess the effectiveness and discriminative ability of the nomogram. Five optimal predictive factors for OS were selected and merged to construct a 3- and 5-year OS nomogram. The nomogram had C-index values of 0.716 and 0.708 in the training cohort and validation cohort, respectively. The actual OS rates and the calibration curves showing the predictions of the nomogram were in good agreement. The prognostic nomogram may be very helpful in estimating the OS of patients with pulmonary LCNEC.

Real-world efficacy of PD-1/PD-L1 inhibitors in patients with advanced pulmonary neuroendocrine carcinoma: a single-center analysis.

Immunotherapy blocking programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) has revolutionized the treatment of extensive-stage small-cell lung cancer (SCLC), but only with limited real-world efficacy data; evidence from immunotherapy for other pulmonary neuroendocrine carcinoma (PNEC) is scarce. The purpose of this study is to evaluate the efficacy of receiving PD-1/PD-L1 inhibitors in patients with advanced PNEC and explore factors related to survival prognosis, providing clues for treatment for patients with advanced PNEC. In all, 203 patients with advanced PNEC who received PD-1/PD-L1 inhibitors between January 2019 and December 2021 were retrospectively analyzed. Kaplan-Meier curves were constructed for progression-free survival (PFS) and overall survival (OS). For the 203 patients, the objective response rate (ORR) was 48.3%, the disease control rate (DCR) was 83.3%, the median PFS (mPFS) was 6.0 months, and the median OS (mOS) was 13.1 months. Among them, the histology was 166 SCLC, 13 large-cell neuroendocrine carcinoma, and 24 other unspecified PNEC. Histologically, no significant difference was observed in PFS (p = 0.240) or OS (p = 0.845). In first-line (1L) treatment (N = 125), patients received chemoimmunotherapy and had an ORR of 64.8%, DCR of 92.0%, mPFS of 6.6 months, and mOS of 14.9 months. In second-line (2L) or later-line setting, the ORR, DCR, mPFS, and mOS were 21.8%, 69.2%, 4.4, and 9.4 months; immunotherapy plus small-molecule antiangiogenic agents showed significantly greater PFS than immunotherapy monotherapy or chemoimmunotherapy (6.4 vs 1.4 vs 3.7 months, p = 0.041). Patients without liver metastasis had superior PFS (7.0 vs 5.1 months, p < 0.001) and OS (19.2 vs 9.6 months, p < 0.001) than those with liver metastasis. In clinical practice, PD-1/PD-L1 inhibitors are effective in patients with advanced PNEC, regardless of the pathological histology. The efficacy of 1L immunochemotherapy is worthy of recognition, and the addition of small-molecule antiangiogenic agents to immunotherapy in 2L or later-line treatment provides a better survival trend. Retrospective study.

The outcomes of different regimens depend on the molecular subtypes of pulmonary large-cell neuroendocrine carcinoma: A retrospective study in China.

The optimal systemic treatment for pulmonary large-cell neuroendocrine carcinoma (LCNEC) remains controversial, and recent advances in LCNEC molecular subtype classification have provided potential strategies for assisting in treatment decisions. Our study aimed to investigate the impact of treatment regimens, molecular subtypes and their concordance on clinical outcomes of patients diagnosed with LCNEC. All patients diagnosed with advanced pulmonary LCNEC in Peking Union Medical College Hospital (PUMCH) between January 2000 and October 2021 were enrolled in this retrospective study. The tumor samples were collected and sequenced using a tumor-specific gene panel, while clinical information was retrieved from the medical records system. The survival and therapeutic response were analyzed and compared between different subgroups classified by treatment regimen (SCLC or NSCLC-based), molecular subtype (type I or II) or the combination. In univariate subgroup analysis categorized only by treatment regimen or molecular subtype, there were no differences identified in DCR, ORR, PFS, or OS. Nevertheless, the group with consistent treatment regimen and molecular subtype exhibited significantly longer OS than that of the inconsistent group (median OS 37.7 vs. 8.3 months; p = 0.046). Particularly, the OS of patients with type II LCNEC treated with SCLC-based regimen was significantly prolonged than that of others (median 37.7 vs. 10.5 months; p = 0.039). Collectively, our study revealed the clinical outcomes of different treatment regimens for LCNEC patients highly depend on their molecular subtypes, highlighting the need for sequencing-guided therapy.

Constructing a folate metabolism gene signature for predicting prognosis in pulmonary neuroendocrine carcinomas

Constructing a folate metabolism gene signature for predicting prognosis in pulmonary neuroendocrine carcinomas

Survival comparison of pulmonary neuroendocrine carcinoma, adenocarcinoma with neuroendocrine differentiation, and adenocarcinoma.

Pulmonary adenocarcinoma with neuroendocrine differentiation (ADE_ned) is a relatively uncommon pathological classification, and there exists considerable debate regarding its prognosis and treatment. The purpose of this study was to analyze the survival difference between patients with neuroendocrine carcinoma (NEC), adenocarcinoma (ADE), or ADE_ned and to investigate the prognostic factors influencing the outcomes of individuals diagnosed with pulmonary ADE_ned. We retrieved information on 316 cases of ADE_ned, 188,823 cases of ADE, and 71,154 cases of NEC diagnosed between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. To account for potential confounding variables, propensity score matching (PSM) was employed. Comparative analyses were conducted to estimate the overall survival (OS) and cancer-specific survival (CSS). Finally, the Cox regression models were used to identify prognostic factors associated with pulmonary ADE_ned. Prior to PSM, patients with lung ADE_ned had a worse OS rate than did those with lung ADE or NEC (5-year OS rate: 13.3% vs. 26.6% vs. 15.6%; P<0.001 and P=0.009, respectively). In terms of CSS, the 5-year CSS rate of patients with ADE_ned was superior to that of NEC but inferior to that of ADE (28.7% vs. 26.8% vs. 43.8%; P=0.006 and P<0.001, respectively). Following PSM, the 5-year survival rate of patients with ADE_ned remained lower than that of individuals with ADE or NEC in terms of OS (13.3% vs. 24.4% vs. 23.0%; P<0.001 and P<0001, respectively) and CSS (28.8% vs. 58.6% vs. 43.1%; P<0.001 and P=0.006, respectively). Finally, the results of the competitive risk regression analysis demonstrated that several variables, including sex, T stage, N stage, M stage, and surgery, were found to be independent prognostic factors for patients diagnosed with pulmonary ADE_ned (all P values <0.05). Patients with lung ADE_ned had a significantly poorer survival outcome compared to those with lung ADE or NEC. Furthermore, sex, tumor-node-metastasis (TNM) stage, and surgery were found to be independent prognostic indicators for cases with lung ADE_ned.

Does subtyping of high-grade pulmonary neuroendocrine carcinomas have an impact on therapy selection?

Small cell lung cancer (SCLC) and large cell neuroendocrine carcinomas (LCNEC) are characterized by a rapid progressive course. Therapy for SCLC has not much changed for decades, and in LCNEC controversies exist, favoring either SCLC-like or non-small cell lung cancer (NSCLC)-like therapy. Three subtypes of SCLC identified in cell cultures, namely ASCL1, NeuroD1, and POU2F3 have been confirmed by immunohistochemistry. The fourth type based on the expression of YAP1 was questioned, and another type, inflamed SCLC, was proposed. SCLC and LCNEC samples were investigated by immunohistochemistry for different subtypes. Additionally, immunohistochemical markers as potential tools to identify patients who might respond to targeted treatment were investigated. For validation a biopsy set was added. ASCL1, NeuroD1, and POU2F3 were expressed in different percentages in SCLC and LCNEC. Similar percentages of expression were found in biopsies. ATOH was expressed in combination with one of the subtypes. YAP1 and TAZ were expressed in some SCLC and LCNEC cases. HES1 expression was seen in few cases. Predominantly stroma cells expressed programmed cell death ligand 1 (PD-L1). The dominant MYC protein was N-MYC. Aurora kinase A (AURKA) was expressed in the majority of both carcinomas, whereas fibroblast growth factor receptor 2 (FGFR2) in few. SCLC and LCNEC can be subtyped into ASCL1-, NeuroD1-, and POU2F3-positive types. AURKA expression and positivity for N-MYC protein was not associated with subtypes. AURKA and FGFR2 are both possible targets for inhibition in SCLC and LCNEC, but patients' selection should be based on expression of the enzyme. Combined chemo- and immunotherapy might be decided by PD-L1 staining of stroma cells.

Prognostic implications of synaptophysin, CD56, thyroid transcription factor-1, and Ki-67 in pulmonary high-grade neuroendocrine carcinomas

BackgroundThe correlation between the expression of immunohistochemical markers and the clinicopathological characteristics of pulmonary high-grade neuroendocrine carcinomas (HGNEC) and its impact on the clinical outcomes of individuals with HGNEC has not yet been explored. MethodsThis study enrolled patients diagnosed with HGNEC between April 2015 and July 2023. Based on the expression levels of synaptophysin (Syn), the neural cell adhesion molecule (CD56), thyroid transcription factor-1 (TTF-1), and Ki-67, a comprehensive analysis was conducted. This involved a comparison of clinicopathological characteristics, chemosensitivity, overall survival (OS), and progression-free survival (PFS). Furthermore, the study identified prognostic factors associated with patient survival through univariate and multivariate analyses. ResultsEighty-two patients were analyzed. Significant differences were identified in tumor stage (χ2 = 5.473, P = 0.019), lymphatic invasion (χ2 = 8.839, P = 0.003), and distant metastasis (χ2 = 5.473, P = 0.019), respectively, between the CD56 positive and negative groups. A significant difference in lymphatic invasion was observed (χ2 = 9.949, P = 0.002) between the CD56 positive and negative groups. A significant difference in vascular invasion was observed (χ2 = 5.106, P = 0.024) between the low and high Ki-67 groups. Compared to the Syn negative group, the Syn positive group had significantly shorter PFS (P = 0.006). Compared to the Syn negative group, the Syn positive group had significantly shorter OS (P = 0.004). The CD56 positive group also had significantly shorter OS than the CD56 negative group (P = 0.027). Univariate analysis revealed that tumor stage and Syn expression were associated with OS and PFS. Lymphatic invasion and CD56 expression were associated with OS. Multivariate analysis revealed that tumor stage was the strongest predictor of poor prognosis for OS (hazard ratio [HR] 0.551, 95 % confidence interval [CI] 0.328–0.927, P = 0.025) and PFS (HR 0.409, 95 % CI 0.247–0.676, P < 0.001). ConclusionsPositive expression of Syn was associated with reduced PFS and OS, while positive CD56 expression was correlated with a shorter OS in HGNEC. The TNM stage was an independent risk factor that significantly influenced PFS and OS in patients with HGNEC. More studies are needed to make further progress in future treatment.

EP13.05-06 Effects and Outcomes Analysis of Immunotherapy for Patients with Pulmonary Large-Cell Neuroendocrine Carcinoma

EP13.05-06 Effects and Outcomes Analysis of Immunotherapy for Patients with Pulmonary Large-Cell Neuroendocrine Carcinoma

EP13.05-04 Real-world Efficacy of PD-1/PD-L1 Inhibitors in Patients with Advanced Pulmonary Neuroendocrine Carcinoma

EP13.05-04 Real-world Efficacy of PD-1/PD-L1 Inhibitors in Patients with Advanced Pulmonary Neuroendocrine Carcinoma

POU2F3-Expressing Small Cell Lung Carcinoma and Large Cell Neuroendocrine Carcinoma Show Morphologic and Phenotypic Overlap.

Considering the differences in protein expression in small cell lung carcinoma (SCLC) by molecular classification, it is likely that there are differences in morphology, but the relationship between molecular classification and morphology has not been examined. Furthermore, there are limited reports concerning this molecular classification for large cell neuroendocrine carcinoma (LCNEC) and SCLC simultaneously. Therefore, we investigated the relationship between immunohistochemistry-based molecular classification and morphology, protein expression, and clinical features of 146 consecutive resection specimens of pulmonary neuroendocrine carcinoma (NEC), focusing mainly on POU2F3, the master transcription factor involved in tuft cell generation. POU2F3-dominant SCLC (n=24) and LCNEC (n=14) showed overlap in cytomorphology, while non-POU2F3-dominant SCLC (n=71) and LCNEC (n=37) showed distinct differences in cytomorphology. In addition, POU2F3-dominant NEC exhibited significantly more abundant tumor stroma, more prominent nest formation, more frequent bronchial intraepithelial involvement, and less frequent background fibrosis than non-POU2F3-dominant NEC. Immunohistochemically, POU2F3-dominant SCLC and LCNEC were characterized by lower expression of TTF-1, CEA, and neuroendocrine markers and higher expression of bcl-2, c-Myc, and c-kit. Clinically, POU2F3-dominant NEC had a significantly better prognosis than non-POU2F3-dominant NEC for recurrence-free survival. POU2F3-dominant NEC had a higher smoking index than non-POU2F3-dominant NEC. POU2F3-dominant NEC forms a unique population, exhibiting intermediate morphologic features between SCLC and LCNEC, with distinct protein expression as tuft cell-like carcinoma. Recognition of this unique subtype may provide clues for solving the long-standing issues of NEC and appropriate therapeutic stratification. It is important to accurately identify POU2F3-expressing carcinomas by immunohistochemistry and to analyze their clinicopathological features.

Implication of cytoplasmic p53 expression in pulmonary neuroendocrine carcinoma using next-generation sequencinganalysis.

Cytoplasmic p53 expression indicates a high frequency of TP53 abnormalities in gynaecological carcinoma. However, the implication of this expression in pulmonary neuroendocrine carcinoma (NEC) remains unclear. Thus, our study aimed to fill this research gap. Immunohistochemistry (IHC) of p53 was performed on 146 cases of resected small-cell lung carcinoma and large-cell NEC, and next-generation sequencing was conducted on cases showing cytoplasmic and wild-type p53 expression. IHC revealed overexpression in 57% of the cases (n = 83), complete absence in 31% (n = 45), cytoplasmic expression in 8% (n = 12) and wild-type expression in 4% (n = 6) of the cases. TP53 mutations were identified in nine of the 13 cases with available genetic analysis. The TP53 mutation rates in cases with cytoplasmic and wild-type p53 expression were 88% (seven of eight) and 40% (two of five), respectively. All seven cases showing cytoplasmic expression with TP53 mutations harboured loss-of-function type mutations: four had mutations in the DNA-binding domain, two in the nuclear localisation domain and one in the tetramerisation domain. Clinically, cases with cytoplasmic p53 expression had a poor prognosis similar to that in cases with p53 overexpression or complete absence. Cytoplasmic p53 expression in patients with pulmonary NEC suggests a high TP53 mutation rate, which is associated with a poor prognosis similar to that in patients with p53 overexpression or complete absence. This cytoplasmic expression should not be misidentified as a wild-type expression. This is the first report, to our knowledge, that demonstrates the implication of cytoplasmic p53 expression in pulmonary NEC.

Exploring the molecular features and genetic prognostic factors of pulmonary high-grade neuroendocrine carcinomas

Molecular research on large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung cancer (SCLC) has progressed significantly. However, there are still fewer molecular markers related to prognostic/therapeutic strategies for these conditions compared to those for adenocarcinoma. We therefore investigated the molecular characteristics of neuroendocrine carcinomas (NECs). We enrolled patients surgically diagnosed with NECs between 2011 and 2019, with complete follow-up records. All were analyzed using whole exome sequencing and p53/Rb immunohistochemistry (IHC). A total of 92 cases, comprising 45 pure SCLC, 15 combined SCLC, 27 pure LCNEC, and 5 combined LCNEC, were included. TP53 (78.3%) and RB1 (34.8%) were the most common molecular alterations, followed by KMT2D, LRP1B, FAT3, NCOR2, SPTA1, and NOTCH1. The mutation frequency for EGFR was 10.9%. Sixteen patients with LCNEC who had TP53/RB1 co-alterations were SCLC-like, while the remaining were NSCLC-like. There was no statistically significant difference between the groups regarding overall survival (OS; p=0.458) and progression-free survival (PFS; p=0.157). The frequency of the loss of Rb expression by IHC in SCLC-like LCNEC was 100%. Significant pathway alterations unique to SCLC included Notch and AMPK, while HIF-1 was enriched exclusively in LCNEC. NCOR2 mutation was linked to worse OS (p=0.029) and PFS (p=0.015), while wild-type SPTA1 was associated with poor PFS (p=0.018). IHC for Rb was reliable for predicting LCNEC molecular subtypes, indicating its clinical value. NCOR2 and SPTA1 alterations were identified as prognostic factors that may provide therapeutic targets for patients with NEC.