Clinical and Pathologic Differences between Small-Cell Carcinoma and Large-Cell Neuroendocrine Carcinoma of the Lung.

BACKGROUND: Both small-cell carcinoma (SCLC) and large-cell neuroendocrine carcinoma (LCNEC) of the lung are often clinically dealt with as being in the same category as neuroendocrine carcinoma, and their clinical differences have not been adequately assessed. METHODS: The postoperative prognosis was retrospectively analyzed using the data of 196 patients who underwent resection for SCLC or LCNEC. RESULTS: Of the patients included, 99 (50.5%) had SCLC and 97 (49.5%) had LCNEC. The median duration of follow-up was 39 months (interquartile range [IQR] 21-76) and 56 months (IQR 21-87) for SCLC and LCNEC, respectively. The estimated 5-year overall survival (OS) probabilities were 53.7% and 62.7% (p = 0.133) for patients with SCLC and LCNEC, respectively. In the SCLC group, a multivariate analysis showed that adjuvant chemotherapy (hazard ratio 0.54, 95% confidence interval 0.30-0.99, p = 0.04) was the only factor that was significantly associated with OS. In the LCNEC group, univariate analyses demonstrated that pathologic stage I (p = 0.01) was the only factor that was associated with better OS after surgery. CONCLUSIONS: We found different clinical features in SCLC and LCNEC; in patients with SCLC, because OS could be expected to significantly improve with postoperative adjuvant chemotherapy, patients with resected SCLC of any pathologic stage should receive adjuvant chemotherapy. For patients with LCNEC, because pathologic stage I LCNEC is related to better prognosis than any other stages, a thorough clinical staging, including invasive staging, according to present guidelines should be performed to identify clinical stage I LCNEC with the highest certainty.

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

AIMS: 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. METHODS AND RESULTS: 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. CONCLUSIONS: 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.

Establishment and Validation of Prognostic Nomograms for Patients with Metastatic Pulmonary Large Cell Neuroendocrine Carcinoma.

PURPOSE: Metastatic pulmonary large cell neuroendocrine carcinoma (LCNEC) is an aggressive cancer with generally poor outcomes. Effective methods for predicting survival in patients with metastatic LCNEC are needed. This study aimed to identify independent survival predictors and develop nomograms for predicting survival in patients with metastatic LCNEC. PATIENTS AND METHODS: We conducted a retrospective analysis using the Surveillance, Epidemiology, and End Results (SEER) database, identifying patients with metastatic LCNEC diagnosed between 2010 and 2017. To find independent predictors of cancer-specific survival (CSS), we performed Cox regression analysis. A nomogram was developed to predict the 6-, 12-, and 18-month CSS rates of patients with metastatic LCNEC. The concordance index (C-index), area under the receiver operating characteristic (ROC) curves (AUC), and calibration curves were adopted with the aim of assessing whether the model can be discriminative and reliable. Decision curve analyses (DCAs) were used to assess the model's utility and benefits from a clinical perspective. RESULTS: This study enrolled a total of 616 patients, of whom 432 were allocated to the training cohort and 184 to the validation cohort. Age, T staging, N staging, metastatic sites, radiotherapy, and chemotherapy were identified as independent prognostic factors for patients with metastatic LCNEC based on multivariable Cox regression analysis results. The nomogram showed strong performance with C-index values of 0.733 and 0.728 for the training and validation cohorts, respectively. ROC curves indicated good predictive performance of the model, with AUC values of 0.796, 0.735, and 0.736 for predicting the 6-, 12-, and 18-month CSS rates of patients with metastatic LCNEC in the training cohort, and 0.795, 0.801, and 0.780 in the validation cohort, respectively. Calibration curves and DCAs confirmed the nomogram's reliability and clinical utility. CONCLUSION: The new nomogram was developed for predicting CSS in patients with metastatic LCNEC, providing personalized risk evaluation and aiding clinical decision-making.

An elderly case of paraneoplastic anti-NMDA receptor encephalitis associated with large cell neuroendocrine carcinoma of the lung.

BACKGROUND: Recent studies have suggested that N-methyl-D-aspartate (NMDA) receptors are involved in the cell proliferation in several tumors. However, there have been no reports demonstrating the expression of NR1 subunit of the NMDA receptor in large cell neuroendocrine carcinoma (LCNEC). CASE PRESENTATION: Here, we report the first elderly case of paraneoplastic anti-NMDA receptor encephalitis associated with LCNEC of the lung with NR1 expression. Of note, NR1 subunit expression in the tumor cells of the present case was confirmed by immunohistochemistry (IHC). Radiation therapy and immunotherapies, such as corticosteroids and intravenous immunoglobulin (IVIG), shrank the tumors and improved neurological symptoms in the present case. Additionally, we also confirmed the expression of NR1 in the tumor cells obtained from three other cases with LCNEC of the lung at our hospital by IHC. CONCLUSION: Our IHC results indicate that LCNEC generally expresses NR1 subunit and NMDA receptor may be involved in the tumor development and growth.

Clinical activity of pembrolizumab with or without chemotherapy in advanced pulmonary large-cell and large-cell neuroendocrine carcinomas: a multicenter retrospective cohort study.

BACKGROUND: Immune checkpoint inhibitors (ICI)-based combination strategies have improved the survival outcomes in advanced non-small cell lung cancers; however, data regarding their efficacy remains limited for uncommon histological types, including large-cell carcinoma (LCC) and large-cell neuroendocrine carcinoma (LCNEC). METHODS: We retrospectively analyzed a total of 60 patients with advanced LCC and LCNEC - 37 treatment-naïve and 23 pre-treated - who received pembrolizumab with or without chemotherapy. Treatment and survival outcomes were analyzed. RESULTS: Of the 37 treatment-naïve patients who received first-line pembrolizumab combined with chemotherapy, the 27 patients with LCC had an overall response rate (ORR) of 44.4% (12/27) and a disease control rate (DCR) of 88.9% (24/27); whereas 10 patients with LCNEC had an ORR of 70% (7/10) and DCR of 90% (9/10). The median progression-free survival (mPFS) was 7.0 months (95% confidence intervals [CI]: 2.2-11.8) and median overall survival (mOS) was 24.0 months (95%CI: 0.0-50.1) for first-line pembrolizumab plus chemotherapy of LCC (n = 27), whereas mPFS was 5.5 months (95%CI: 2.3-8.7) and mOS was 13.0 months (95%CI: 11.0-15.0) for first-line pembrolizumab plus chemotherapy of LCNEC (n = 10). Of the 23 pre-treated patients who received subsequent-line pembrolizumab with or without chemotherapy, mPFS was 2.0 months (95% CI: 0.6-3.4) and mOS was 4.5 months (95% CI: 0.0-9.0) for LCC and mPFS was 3.8 months (95% CI: 0.0-7.6) and mOS was not reached for LCNEC. CONCLUSION: Our study provides real-world clinical evidence of the anti-tumor activity of pembrolizumab plus chemotherapy in advanced LCC and LCNEC, indicating that this regimen could serve as a treatment option, particularly as first-line therapy, for improving the survival outcomes of patients with these rare histological subtypes of lung cancer. TRIAL REGISTRATION: NCT05023837(ESPORTA, 27/08/2021).

Incidence, survival comparison, and novel prognostic evaluation approaches for stage iii-iv pulmonary large cell neuroendocrine carcinoma and small cell lung cancer.

BACKGROUND: Pulmonary large cell neuroendocrine carcinoma (LCNEC) and small cell lung cancer (SCLC) are two types of high-grade neuroendocrine carcinomas of the lung with poor prognosis. LCNEC has not been thoroughly studied due to its rarity, data are also lacking regarding the survival comparison and prognosis analysis of patients with locally advanced or metastatic LCNEC and SCLC. METHODS: Data of patients with LCNEC, SCLC, and other NSCLC who were diagnosed from 1975 to 2019 were extracted from the Surveillance, Epidemiology and End Results (SEER) database to estimate incidence. Those in stage III-IV and being diagnosed from 2010 to 2015 were utilized further to investigate their clinical characteristics and prognosis. Propensity score matching (PSM) analyses at a ratio of 1:2 was used to compare their survival outcomes. Nomograms of LCNEC and SCLC were established with internal validation, and the nomogram of SCLC was externally validated by 349 patients diagnosed in Cancer hospital, Chinese Academy of Medical Sciences & Peking Union Medical College from January 1, 2012 to December 31, 2018. RESULTS: The incidence of LCNEC has been increasing in recent decades, meanwhile that of SCLC and other types of NSCLC were decreasing. A total of 91,635 lung cancer patients, including 785 with LCNEC, 15,776 with SCLC, and 75,074 with other NSCLC were enrolled for further analysis. The survival of stage III-IV LCNEC resembles that of SCLC, and significantly worse than other types of NSCLC before and after PSM analysis. In pretreatment prognostic analysis, age, T stage, N stage, M stage, bone metastasis, liver metastasis, and brain metastasis were found to be associated with the survival of both LCNEC and SCLC, besides sex, bilaterality, and lung metastasis were additional prognostic factors for SCLC. Two nomograms and convenient online tools respectively for LCNEC and SCLC were established accordingly with favorable predicting accuracy of < 1-year, < 2-year, < 3-year survival probabilities. In external validation of the SCLC nomogram with a Chinese cohort, the AUCs of 1-year, 2-year and 3-year ROC were 0.652, 0.669, and 0.750, respectively. All the results of 1-, 2-, 3- year variable-dependent ROC curves verified the superior prognostic value of our nomograms for LCNEC and SCLC over the traditional T/N/M staging system. CONCLUSIONS: Based on large sample-based cohort, we compared the epidemiological trends and survival outcomes between locally advanced or metastatic LCNEC, SCLC, and other NSCLC. Furthermore, two prognostic evaluation approaches respectively for LCNEC and SCLC might present as practical tools for clinicians to predict the survival outcome of these patients and facilitate risk stratification.

The prognostic impact of a high number of peritumoral alveolar macrophages in neuroendocrine carcinoma in the lung.

Alveolar macrophages (AMs) are resident macrophages in the lungs; however, whether the number of AMs plays a role in the lung neuroendocrine tumor (NET) prognosis remains unclear. We counted the number of AMs located around the tumor (peritumoral alveolar macrophages [pAMs]) and the number of AMs located apart from the tumor (distant macrophages; dAMs). In 73 cases of neuroendocrine carcinoma (NEC: small cell lung carcinoma and large cell neuroendocrine carcinoma), the group that contained higher pAMs (≥86/µm2 ) revealed shorter recurrent-free survival (RFS) than those with lower pAMs (<86/µm2 ) (p = 0.005). Bivariate analysis showed that the number of pAMs was an independent predictor of a poor RFS. In contrast, in the carcinoid tumor cohort (n = 29), there was no statistically significant correlation between the two groups with high and low numbers of pAMs in RFS (p = 0.113). Furthermore, we examined the correlation between genomic alterations and the number of pAMs in NEC, but no significant correlation was observed. In conclusion, the number of pAMs is a prognostic factor for NEC in the lung and pAMs may contribute to tumor progression within the peritumoral microenvironment.

Different Characteristics and Survival between Surgically Resected Pure and Combined Pulmonary Large Cell Neuroendocrine Carcinoma.

BACKGROUND: Large cell neuroendocrine carcinoma (LCNEC) is a rare high-grade neuroendocrine carcinoma of the lung. Little is known about the differences between the pure and combined LCNEC subtypes, and thus we conducted this study to provide more comprehensive insight into LCNEC. METHODS: We reviewed 221 patients with pure LCNEC (P-LCNEC) and 120 patients with combined LCNEC (C-LCNEC) who underwent pulmonary surgery in our hospital to compare their clinical features, driven genes' status (EGFR/ALK/ROS1/KRAS/BRAF), and adjuvant chemotherapy regimens. Propensity score matching (PSM) was applied to reduce selection bias. RESULTS: The P-LCNEC group included a higher proportion of males and smokers than the C-LCNEC group. Furthermore, the C-LCNEC group had higher incidences of visceral pleural invasion (VPI), EGFR mutation and ALK rearrangement compared with the P-LCNEC group. Expression of neuroendocrine markers (CD56, CGA, and SYN) and recurrence patterns were not significantly different between the two groups. The P-LCNEC group had better disease-free survival (DFS) and overall survival (OS) compared with the C-LCNEC group (median DFS: 67.0 vs. 28.1 months, p = 0.021; median OS: 72.0 vs. 45.0 months, p = 0.001), which was further confirmed by the PSM method (p = 0.004 and p < 0.001, respectively). Adjuvant chemotherapy was also an independent factor for DFS and OS. Subgroup analysis found that regardless of whether it was for the entire LCNEC group or the P- and C-LCNEC subtypes, the small cell lung cancer (SCLC) regimens presented with superior survival compared with the non-small cell lung cancer (NSCLC) regimens. CONCLUSION: P-LCNEC was associated with more favorable prognosis compared with C-LCNEC. SCLC-based adjuvant chemotherapy was more appropriate for LCNEC patients than NSCLC-based regimens, regardless of whether they were the pure or combined LCNEC subtypes. C-LCNEC patients may be the potential beneficiary of targeted therapy.

Pulmonary neuroendocrine carcinomas in situ: do they exist?

Although precursor lesions of pulmonary squamous carcinoma, adenocarcinoma and carcinoid tumour are well known and accepted entities, precursor lesions of pulmonary neuroendocrine carcinomas, i.e. small-cell lung carcinoma and large-cell neuroendocrine carcinoma, have never been identified. A small body of literature documenting intraepithelial involvement in cases of pulmonary neuroendocrine carcinoma begs the question of whether the intraepithelial lesion represents de-novo intraepithelial neoplasia or invasion by underlying tumour. In this article, the literature on cases of invasive neuroendocrine carcinomas with an intraepithelial component showing a neuroendocrine immunophenotype is thoroughly and critically reviewed. The authors of the publications of cases of coexisting invasive and intraepithelial neuroendocrine carcinoma generally favour invasion as the explanation for the intraepithelial component. However, in practice, it is difficult or impossible to determine the direction of migration of tumour cells when there is both an invasive component and an intraepithelial component. Pulmonary neuroendocrine carcinomas in situ have been produced in genetically engineered mouse models. On the basis of the illustrations in the literature of human cases and the production of pulmonary neuroendocrine carcinomas in situ in genetically engineered mice, it seems likely that these tumours also exist in humans. However, their existence and acceptance require definitive proof. Studies should be undertaken to identify bronchial and other lung biopsies with in-situ carcinoma showing a neuroendocrine immunophenotype and a subsequent negative resection specimen and no follow-up evidence of invasive carcinoma. Documenting such cases would provide definitive proof for the existence of pulmonary neuroendocrine carcinomas in situ in humans.

Comparative study of Rb1, cyclin D1 and p16 immunohistochemistry expression to distinguish lung small-cell carcinoma and large-cell neuroendocrine carcinoma.

AIMS: Large-cell neuroendocrine carcinoma (LCNEC) and small-cell carcinoma (SCLC) of lung encompass high-grade neuroendocrine tumour category and share several fundamental features. As both tumours may respond to different treatment modalities and show unique molecular alterations distinction between the two is clinically relevant, but can be challenging due to sampling and fixation issues and shared morphological features. METHODS: Surgically resected primary SCLC (n = 129) and LCNEC (n = 27) were immunohistochemically stained with Rb1, cyclin D1 and p16 using tissue microarray (TMA), and expression patterns of the proteins were compared between the two to identify the discriminatory pattern. RESULTS: All markers had high diagnostic accuracy; Rb1 was the highest followed by p16 and cyclin D1. The majority of SCLC had the pattern Rb1-/p16+/cyclin D1- and more than half of LCNEC had Rb1+/p16-/cyclin D1+. Overall, the expression pattern Rb1- and cyclin D1- was strongly associated with the diagnosis of SCLC, while the pattern Rb1+ and/or cyclin D1+ was strongly associated with LCNEC. The use of this simplified expression pattern leads to a diagnostic accuracy of 97.3%. p16 did not add to further discrimination. The heterogeneity in Rb1, cyclin D1 and p16 expression was insignificant in SCLCs compared with LCNECs. CONCLUSIONS: Use of Rb1, cyclin D1 and p16 immunohistochemistry can distinguish the two with high accuracy. Notably, the Rb1-/cyclin D1- pattern in given tumour sample would confirm the diagnosis of SCLC. Our results could be extrapolated and applied to routine diagnostic samples such as biopsies and cytology samples.

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.

Platinum Doublet plus Atezolizumab as First-line Treatment in Metastatic Large Cell Neuroendocrine Carcinoma: A Single Institution Experience.

BACKGROUND: Large Cell Neuroendocrine Carcinoma of the Lung (L-LCNEC) is a rare type of neuroendocrine lung cancer that is increasingly diagnosed. However, the optimal management regarding the advanced stage is unclear. The purpose of this article is to present and compare our experience when L-LCNEC is treated as Small Cell Lung Cancer (SCLC). PATIENTS AND METHODS: Overall, eight cases of L-LCNEC were included. We retrospectively reviewed medical files and reports by accessing the Institution's Data of patients diagnosed with L-LCNEC from April 2019 until December 2020 and evaluated their response to the combination of Platinum - Etoposide - Atezolizumab as first-line chemotherapy. RESULTS: The overall observed response rate (ORR) of 75%. The median PFS was 6.85 months. The median response duration was 5.5 months. CONCLUSIONS: Comparing our findings with other retrospective and prospective studies, it seems that the systematic treatment of choice and management in L-LCNEC of the lung should be that of a small cell carcinoma of the lung.

Clinic and genetic similarity assessments of atypical carcinoid, neuroendocrine neoplasm with atypical carcinoid morphology and elevated mitotic count and large cell neuroendocrine carcinoma.

BACKGROUND: Pulmonary neuroendocrine neoplasms can be divided into typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell (lung) carcinoma. According to the World Health Organization, these four neoplasms have different characteristics and morphological traits, mitotic counts, and necrotic status. Importantly, "a grey-zone" neoplasm with an atypical carcinoid-like morphology, where the mitotic rate exceeds the criterion of 10 mitoses per 2 mm2, have still not been well classified. In clinical practice, the most controversial area is the limit of 11 mitoses to distinguish between atypical carcinoids and large cell neuroendocrine carcinomas. METHODS: Basic and clinical information was obtained from patient medical records. A series of grey-zone patients (n = 8) were selected for exploring their clinicopathological features. In addition, patients with atypical carcinoids (n = 9) and classical large cell neuroendocrine carcinomas (n = 14) were also included to compare their similarity to these neoplasms with respect to tumour morphology and immunohistochemical staining. RESULTS: We found that these grey-zone tumour sizes varied and affected mainly middle-aged and older men who smoked. Furthermore, similar gene mutations were found in the grey-zone neoplasms and large cell neuroendocrine carcinomas, for the mutated genes of these two are mainly involved in PI3K-Akt signal pathways and Pathways in cancer, including a biallelic alteration of TP53/RB1 and KEAP1. CONCLUSIONS: Our findings indicate that neuroendocrine neoplasm with atypical carcinoid morphology and elevated mitotic counts is more similar to large cell neuroendocrine carcinoma than atypical carcinoid. Furthermore, this study may help improve diagnosing these special cases in clinical practice to avoid misdiagnosis.

Challenges in Ki-67 assessments in pulmonary large-cell neuroendocrine carcinomas.

AIMS: To gather the best available evidence regarding Ki-67% values in large-cell neuroendocrine carcinoma (LCNEC) and determine whether certain cut-off values could serve as a prognostic feature in LCNEC. METHODS AND RESULTS: Aperio ScanScope AT Turbo, eSlide Manager and ImageScope software (Leica Biosystems) were used to measure Ki-67% in 77 resected LCNEC diagnosed by World Health Organisation (WHO) criteria. Cases were stratified into six classes by 10% Ki-67 increments. Using the Kaplan-Meier method, overall (OS) and disease-free survivals (DFS) were compared by AJCC stage, by six Ki-67% classes and with Ki-67% cut-points ≥20% and ≥40%. Tumours were from 0.9 to 11.5 cm and pathological stages 1-3. The system measured Ki-67% positivity using 4072-44 533 tumour nuclei per case (mean 16610 ± 8039). Ki-67% ranged from 1 to 64% (mean = 26%; median = 26%). Only 16 (21%) tumours had Ki-67% ≥40%. OS ranged from 1 to 298 months (median follow-up = 25 months). DFS ranged from 1 to 276 months (median follow-up = 9 months). OS and DFS differed across AJCC stage (overall log-rank P = 0.038 and P = 0.037). However, neither OS nor DFS significantly correlated with Ki-67% when six or two classes were used with either ≥20% Ki-67 or ≥40% Ki-67 as cut-point. A literature review identified 14 reports meeting our inclusion criteria with ≥10 LCNEC. Reported Ki-67% ranged from 2% to 100%. Problems contributing to variability in Ki-67% measurements are discussed. CONCLUSION: Our findings caution against a blanket use of 20%, 40% or other Ki-67% cut-points for LCNEC diagnosis or prognostication.

Successful salvage of recurrent leptomeningeal disease in large cell neuroendocrine lung cancer with stereotactic radiotherapy.

A 70-year old male with stage I large cell neuroendocrine carcinoma (LCNEC) of the lung underwent resection of a metachronous 5 cm brain metastasis and received postoperative hypofractionated stereotactic radiotherapy (hfSRT). Five sequential nodular leptomeningeal metastases up to 5.3 cm in diameter were diagnosed on MRI within 10 months and were treated with SRT. Currently the patient has no evidence of intracranial disease 24 months after last irradiation without chemotherapy or whole brain radiotherapy. This is the first report of sustained complete remission of multiple large leptomeningeal metastases achieved with hfSRT, highlighting this brain-sparing approach in selected patients with LCNEC lung cancer.

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.

Neuroendocrine carcinoma of the common bile duct associated with congenital bile duct dilatation: a case report.

BACKGROUND: Cholangiocarcinoma is frequently observed in patients with congenital bile duct dilatation (CBDD). Most cholangiocarcinomas are adenocarcinomas. Other types, especially neuroendocrine carcinomas (NECs), are rare. To the best of our knowledge, this is the third reported case of an NEC of the common bile duct associated with CBDD and the first to receive adjuvant chemotherapy for advanced disease. CASE PRESENTATION: A 29-year-old woman presented with upper abdominal pain. Preoperative imaging indicated marked dilatation of the common bile duct and a tumor in the middle portion of the common bile duct. She was suspected of having distal cholangiocarcinoma associated with CBDD and underwent pylorus-preserving pancreaticoduodenectomy. Pathological and immunohistological findings led to a final diagnosis of large-cell NEC (pT3aN1M0 pStageIIB). The postoperative course was uneventful, and she was administered cisplatin and irinotecan every 4 weeks (four cycles) as adjuvant chemotherapy. She has remained recurrence-free for 16 months. CONCLUSIONS: NEC might be a differential diagnosis in cases of cholangial tumor associated with congenital bile duct dilatation. This presentation is rare and valuable, and to establish better treatment for NEC, further reports are necessary.

Efficacy and Safety of Anti-Programed Death-1 Blockade in Previously Treated Large-Cell Neuroendocrine Carcinoma.

BACKGROUND: Large-cell neuroendocrine carcinoma (LCNEC) of the lung is a rare tumor with an aggressive clinical course. However, there is limited knowledge of its treatment strategy. This retrospective study aimed to assess the efficacy and safety of anti-programed death-1 (PD-1) blockade monotherapy in previously treated advanced LCNEC. METHODS: Eleven patients with previously treated advanced LCNEC who received immune checkpoint inhibitor monotherapy between January 2015 and November 2020 were retrospectively analyzed for efficacy and safety. RESULTS: Of a total of 11 patients (median [range] age, 66 [37-79] years; 8 men [73%] and 3 women [27%]), 8 patients had performance status (PS) 0-1 [73%] and 3 patients had PS 2 [27%]; 9 patients received 1 prior chemotherapy [82%] and 2 patients received 2 prior chemotherapies [18%]. The median follow-up duration was 4.6 months. Although PD-1 blockade was administered at median cycles of 3 (range, 1-12), overall response rate, median progression-free survival, and median overall survival were 9.1%, 2.7 months, and 4.6 months, respectively. Any adverse events were observed in 9 patients (82%), including 1 patient with grade 3 pneumonitis as a serious adverse event. CONCLUSION: Anti-PD-1 blockade monotherapy as a subsequent line for previously treated advanced LCNEC exhibited usefulness and tolerability and was identified as a valid treatment option.

Efficacy of immune checkpoint inhibitors in non-small cell lung cancer with uncommon histology: a propensity-score-matched analysis.

BACKGROUND: Clinical efficacy of immune checkpoint inhibitors (ICIs) for non-small cell lung cancer (NSCLC) with uncommon histology (uNSCLC) is unknown. METHODS: Patients with NSCLC treated with ICI monotherapy between January 2014 and December 2018 in 10 Japanese hospitals were retrospectively evaluated. The patients were divided into: (1) NSCLC with common histology (cNSCLC), defined as adenocarcinoma and squamous cell carcinoma; and (2) uNSCLC, defined as incompatibility with morphological and immunohistochemical criteria for adenocarcinoma or squamous cell carcinoma. Propensity score matching was performed to balance the two groups. RESULTS: Among a total of 175 patients included, 44 with uNSCLC (10 pleomorphic carcinomas, 9 large cell neuroendocrine carcinomas, 2 large cell carcinomas, and 23 not otherwise specified) and 44 with matched cNSCLC (32 adenocarcinomas and 12 squamous cell carcinomas) were selected for analyses. Median progression-free survival (PFS) (4.4 months, 95% confidence interval [CI] 1.8-7.7 months) and overall survival (OS) (11.4 months, 95% CI 7.4-27.4 months) in the uNSCLC patients were not significantly different from those in matched cNSCLC patients (5.4 months, 95% CI 3.1-7.6 months, p = 0.761; and 14.1 months, 95% CI 10.6-29.6 months, p = 0.381). In multivariate analysis, Eastern Cooperative Oncology Group performance status (ECOG-PS) of 0-1 and programmed death ligand-1 (PD-L1) expression were predictive for PFS and OS in uNSCLC. CONCLUSIONS: ICIs had similar clinical efficacy for treatment of uNSCLC and cNSCLC. Good ECOG-PS and PD-L1 expression were predictive for efficacy of ICIs in uNSCLC.

Ubiquitin C-terminal hydrolase-L1 has prognostic relevance and is a therapeutic target for high-grade neuroendocrine lung cancers.

High-grade neuroendocrine lung cancer (HGNEC), which includes small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC) of the lung is a rapidly proliferating, aggressive form of lung cancer. The initial standard chemotherapeutic regimens of platinum doublets are recommended for SCLC and have been frequently used for LCNEC. However, there are currently no molecularly targeted agents with proven clinical benefit for this disease. The deubiquitinating enzyme ubiquitin C-terminal hydrolase-L1 (UCHL1) is a neuroendocrine cell-specific product that is known as a potential oncogene in several types of cancer, but little is known about the biological function of UCHL1 and its therapeutic potential in HGNEC. In this study, we found that preclinical efficacy evoked by targeting UCHL1 was relevant to prognosis in HGNEC. UCHL1 was found to be expressed in HGNEC, particularly in cell lines and patient samples of SCLC, and the combined use of platinum doublets with selective UCHL1 inhibitors improved its therapeutic response in vitro. Immunohistochemical expression of UCHL1 was significantly associated with postoperative survival in patients with HGNEC and contributed towards distinguishing SCLC from LCNEC. Circulating extracellular vesicles (EV), including exosomes isolated from lung cancer cell lines and serum from early-stage HGNEC, were verified by electron microscopy and nanoparticle tracking analysis. Higher levels of UCHL1 mRNA in EV were found in the samples of patients with early-stage HGNEC than those with early-stage NSCLC and healthy donors' EV. Taken together, UCHL1 may be a potential prognostic marker and a promising druggable target for HGNEC.