Pulmonary large cell neuroendocrine carcinoma demonstrates high proliferative activity

Whole-genome characterization of large-cell lung carcinoma: A comparative analysis based on the histological classification

Background: According to the 2015 World Health Organization classification, large cell neuroendocrine carcinoma (LCNEC) was isolated from Large-cell lung cancer (LCLC) tumors, which constitutes 2%-3% of non-small cell lung cancer (NSCLC). However, LCLC tumors are still fairly vaguely defined at the molecular level compared to other subgroups. Materials and Methods: In this study, whole-genome sequencing (WGS) was performed on 23 LCLC and 15 LCNEC tumor specimens. Meanwhile, data from the TCGA (586 LUADs and 511 LUSCs) and U Cologne (120 SCLCs) were analyzed and compared. Results: The most common driver mutations were found in TP53 (13/23, 57%), FAM135B (8/23, 35%) and FAT3 (7/23, 30%) in LCLC, while their counterparts in LCNEC were TP53 (13/15, 87%), LRP1B (6/15, 40%) and FAT1 (6/15, 40%). Notably, FAM135B mutations only occurred in LCLC (P = 0.013). Cosmic signature analysis revealed widespread defective DNA mismatch repair and tobacco-induced mutations in both LCLC and LCNEC. Additionally, LCNEC had a higher incidence of chromosomal copy number variations (CNVs) and structural variations (SVs) compared with LCLC, although the differences were not statistically significant. Particularly, chromothripsis SVs was significantly associated with CNVs. Furthermore, mutational landscape of different subtypes indicated differences between subtypes, and there seems to be more commonalty between our cohort and SCLC than with other subtypes. SMARCA4 mutations may be specific driver gene alteration in our cohort. Conclusion: Our results support that LCLC and LCNEC tumors follow distinct tumorigenic pathways. To our knowledge, this is the first genome-wide profiling comparison of LCLC and LCNEC.

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.

Neuroendocrine tumors of the lung: clinicopathological and molecular features

In 1970, neuroendocrine tumors of the lung were classified into three categories: typical carcinoid (TC), atypical carcinoid (AC), and small cell lung carcinoma (SCLC). The third edition of the World Health Organization (WHO) classification in 1999 defined large cell neuroendocrine carcinoma (LCNEC) as a variant of large cell carcinomas, whereas the fourth edition of the WHO classification redefined LCNEC as a neuroendocrine tumor. Currently, neuroendocrine tumors of the lung are classified into four main categories: TC, AC, LCNEC, and SCLC. Although the treatments for TC, AC, and SCLC have not changed remarkably, the treatment strategy for LCNEC is not yet established because of its reclassification from a variant of "large cell carcinoma" to a new category of "neuroendocrine tumor". In this review article, we discuss the pathological findings, biological behavior, and treatment of neuroendocrine tumors of the lung.

Adjuvant chemotherapy for large-cell neuroendocrine lung carcinoma: results from the European Society for Thoracic Surgeons Lung Neuroendocrine Tumours Retrospective Database

OBJECTIVES

Large-cell neuroendocrine carcinoma (LCNC) is a rare tumour characterized by aggressive biological behaviour and poor prognosis. Due to its rarity and the lack of randomized clinical trials, the best treatment is still under debate. Some recent reports indicate that adjuvant chemotherapy (CT) may have a beneficial effect on survival. Our goal was to evaluate this finding using a large series of patients with neuroendocrine tumours obtained from the European Society of Thoracic Surgeons database.

METHODS

Data for 400 patients with LCNC operated on in 14 thoracic surgery institutions worldwide between 1992 and 2014 were collected retrospectively. Overall survival was the primary endpoint; we used a multivariable Cox regression model to evaluate which clinical variables may influence patient outcomes; we also focused on the possible prognostic role of adjuvant CT. A propensity score (PS) analysis using the inverse probability of treatment weighting was also carried out.

RESULTS

The 3- and 5-year survival rates were 54.1% and 45%, respectively. With the multivariable model, we found that increasing age, Eastern Cooperative Oncology Group Performance Status ≥2 and advanced TNM stage were indicators of poor prognosis. Weak evidence of a higher overall survival in patients receiving adjuvant CT (adjusted hazard ratio 0.73; 95% confidence interval: 0.56-0.96, P  = 0.022) was observed.

CONCLUSIONS

A trend towards benefit from adjuvant CT has been observed in patients with LCNC. Although surgical procedures remain the mainstay of curative options, combination with other treatments (e.g. neoadjuvant CT/radiotherapy) should be evaluated by future studies.

Large-Cell Neuroendocrine Carcinoma of the Lung

BACKGROUND

Large-cell neuroendocrine carcinoma (LCNEC) of the lung displays morphologic and immunohistochemical characteristics common to neuroendocrine tumors and morphologic features of large-cell carcinomas. Because surgical resection of LCNEC in many series has been described with 5-year actuarial survival that is far worse than that reported for other histologic variants of non-small-cell lung cancer (NSCLC), considerable debate has emerged as to whether these tumors should be classified and treated as NSCLC or small-cell lung cancer.

METHODS

The initial evaluation and diagnosis, tumor classification, surgical treatment, results of therapy, and long-term prognosis of patients with LCNEC based on our experience are discussed, and a review of the literature is presented.

RESULTS

Patients with LCNEC are more likely to develop recurrent lung cancer and have shorter actuarial survival than patients with other histologic types of NSCLC, even in those with stage I disease.

CONCLUSIONS

Accurate differentiation of LCNEC from other types of NSCLC is important because it identifies those patients at highest risk for developing recurrent disease. Efforts to identify effective adjuvant therapies are needed to improve treatment outcomes with this aggressive type of lung cancer.

Mutational and gene fusion analyses of primary large cell and large cell neuroendocrine lung cancer

Large cell carcinoma with or without neuroendocrine features (LCNEC and LC, respectively) constitutes 3-9% of non-small cell lung cancer but is poorly characterized at the molecular level. Herein we analyzed 41 LC and 32 LCNEC (including 15 previously reported cases) tumors using massive parallel sequencing for mutations in 26 cancer-related genes and gene fusions in ALK, RET, and ROS1. LC patients were additionally subdivided into three immunohistochemistry groups based on positive expression of TTF-1/Napsin A (adenocarcinoma-like, n = 24; 59%), CK5/P40 (squamous-like, n = 5; 12%), or no marker expression (marker-negative, n = 12; 29%). Most common alterations were TP53 (83%), KRAS (22%), MET (12%) mutations in LCs, and TP53 (88%), STK11 (16%), and PTEN (13%) mutations in LCNECs. In general, LCs showed more oncogene mutations compared to LCNECs. Immunomarker stratification of LC revealed oncogene mutations in 63% of adenocarcinoma-like cases, but only in 17% of marker-negative cases. Moreover, marker-negative LCs were associated with inferior overall survival compared with adenocarcinoma-like tumors (p = 0.007). No ALK, RET or ROS1 fusions were detected in LCs or LCNECs. Together, our molecular analyses support that LC and LCNEC tumors follow different tumorigenic paths and that LC may be stratified into molecular subgroups with potential implications for diagnosis, prognostics, and therapy decisions.

Cardiothoracic manifestations of neuroendocrine tumours

Cardiothoracic neuroendocrine tumour (NET) manifestations encompass a vast disease spectrum. Pulmonary neuroendocrine tumours represent a range of tumour grade and differentiation characteristics from pre-malignant diffuse neuroendocrine cell hyperplasia, well-differentiated, low-grade carcinoid tumours with excellent outcomes, through to high-grade small-cell lung carcinoma and large-cell neuroendocrine carcinoma with poor prognoses. Rarer thymic NETs represent a similarly wide neoplastic spectrum. Cardiac carcinoid is a paraneoplastic manifestation of the carcinoid syndrome and often the cause of mortality in NETs with hepatic metastases. Cardiothoracic NET manifestations are reviewed herein from a radiologists' perspective, discussing the diverse clinical presentations, spectrum of neoplastic and paraneoplastic manifestations, imaging features and treatment options.

Beyond adenocarcinoma: current treatments and future directions for squamous, small cell, and rare lung cancer histologies

Lung cancer encompasses a diverse spectrum of histologic subtypes. Until recently, the majority of therapeutic advances were limited to the minority of patients with adenocarcinoma. With the advent of comprehensive genomic profiling of squamous and small cell lung cancers, new therapeutic targets have emerged. For squamous tumors, the most promising of these include fibroblast growth factor receptor (FGFR), the phosphatidylinositol 3-kinase (PI3K) pathway, discoidin domain receptor 2 (DDR2), and G1/S checkpoint regulators. In 2014, the antiangiogenic agent ramucirumab was approved for all non-small cell lung cancer (NSCLC) histologies, including squamous tumors. Immunotherapeutic approaches also appear to be promising for these cases. Genomic analysis of small cell lung cancer has revealed a high mutation burden, but relatively few druggable driver oncogenic alterations. Current treatment strategies under investigation are focusing on targeting mitotic, cell cycle, and DNA repair regulation, as well as immunotherapy. Pulmonary neuroendocrine tumors represent a diverse spectrum of diseases that may be treated with somatostatin analogs, cytotoxic agents, and molecularly targeted therapies. Radiolabeled somatostatin analogs and combinations with mammalian target of rapamycin (mTOR) inhibitors also show potential. Large cell neuroendocrine tumors share numerous clinical, pathologic, and molecular features with small cell lung cancer; however, whether they should be treated similarly or according to a NSCLC paradigm remains a matter of debate.

Ki-67 antigen in lung neuroendocrine tumors: unraveling a role in clinical practice

Classification of lung neuroendocrine (NE) tumors is a step-wise process with four tumor categories being identified by morphology, namely typical carcinoid (TC), atypical carcinoid, large-cell NE carcinoma, and small-cell lung carcinoma (SCLC). Ki-67 antigen or protein (henceforth simply Ki-67) has been largely studied in these tumors, but the clinical implications are so far not clear. A well-defined role has regarded the diagnostic use in the separation of TC and AC from SCLC in nonsurgical specimens, with monoclonal antibody MIB-1 resulting in the most used reagent after antigen retrieval procedures. Uncertainties, however, have arisen in its assessment, usually expressed as Ki-67 labeling index, because of some variability in obtaining either value of the fraction. A diagnostic role is currently lacking, even though there are significant differences in most cases between TC and AC, less so between large-cell NE carcinoma and SCLC. In addition, the prognostic role of Ki-67 is debated, likely due to methodological and biological reasons. The last challenge would be to identify an effective lung-specific grading system based on Ki-67 labeling index. In this review article, five relevant issues to Ki-67 have been addressed by using a question-answer methodology, with relevant key points discussing major interpretation issues. The conclusion is that Ki-67 is a feasible and potentially meaningful marker in lung NE tumors, but more data are needed to determine its ideal function in this setting of tumors.

Automated quantification of Ki-67 proliferative index of excised neuroendocrine tumors of the lung

BACKGROUND

The histopathologic distinction between typical carcinoid (TC) and atypical carcinoid (AC) of the lung is based largely on mitotic index. Ki-67 may aid in separation of these tumors, as well as the distinction from large cell neuroendocrine carcinoma (LCNEC).

METHODS

We identified 55 surgically resected primary neuroendocrine lung tumors (39 TC, 7 AC, 9 LCNEC) based on mitotic rate and histologic features. Ki-67 proliferative index based on automated image analysis, tumor necrosis, nodal metastases, local or distant recurrence, and survival were compared across groups.

RESULTS

The mean mitotic count and Ki-67 index for TC, AC, and LCNEC were 0.1 and 2.3%, 3.4 and 16.8%, and 56.1 and 81.3% respectively. The Ki-67 index did not overlap among groups, with ranges of 0-6.7% for TC, 9.9-25.7% for AC, and 63.2-91.9% for LCNEC. Nodal metastases were identified in 4/39 (10%) TC, 2/7 (22%) AC, and 2/8 (25%) LCNEC. There was no survival difference between TC and AC, but there was a significant survival difference between LCNEC and TC and AC combined (p<0.001). There was a step-wise increase in disease free survival with tumor grade: no TC recurred, 2/7 AC recurred or progressed (median interval 35.5 months), and all LCNEC recurred or progressed (median interval 10.1 months). No patient with TC or AC died of disease, compared to 7/8 LCNEC with follow-up data.

CONCLUSIONS

We conclude that Ki-67 index is a useful diagnostic marker for neuroendocrine tumors, with 7% a divider between AC and TC, and 50% a divider between LCNEC and AC. LCNEC is biologically different from AC and TC, with a much more aggressive course, and a high Ki-67 index.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_174.

Pathology and diagnosis of neuroendocrine tumors: lung neuroendocrine

Neuroendocrine (NE) tumors of the lung include a spectrum from low-grade typical carcinoid (TC) and intermediate-grade atypical carcinoid (AC) to high-grade large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC). Although NE lung tumors are frequently discussed together, as in this article, carcinoids are very different from high-grade SCLC and LCNEC. SCLC and LCNEC are found in heavy-smoking, older patients, whereas smoking is not strongly associated with carcinoid tumors. On a molecular level, SCLC and LCNEC have extensive genetic abnormalities, but there are few in TC and slightly more in AC.

Tyrosine Kinase Inhibitors in EGFR-Mutated Large-Cell Neuroendocrine Carcinoma of the Lung? A Case Report

Large-cell neuroendocrine carcinoma (LCNEC) of the lung is a high-grade carcinoma belonging to the neuroendocrine tumors of the lung and is different from typical lung large-cell carcinoma. It represents about 3% of all pulmonary malignancies and is characterized by neuroendocrine cytologic features. The treatment usually is platinum-based chemotherapy, however the outcome remains poor. Therefore new therapeutic options are needed. Tyrosine kinase inhibitors have demonstrated greater efficacy and better tolerability than standard chemotherapy in non-small-cell lung cancer harboring epidermal growth factor receptor (EGFR) mutations. EGFR gene mutations were also rarely identified in LCNEC. We report a patient with lung LCNEC activating EGFR mutations who showed an impressive response to gefitinib.

Treatment options for patients with large cell neuroendocrine carcinoma of the lung

Large cell neuroendocrine carcinoma (LCNEC) of the lung is categorized as a variant of large cell carcinomas, and LCNEC tumors display biological behaviors resembling those of small cell lung carcinomas and features of high-grade neuroendocrine tumors. Because patients with LCNEC have a poor prognosis, surgery alone is not sufficient. Multimodality therapies, including adjuvant chemotherapy, appear promising for improved prognosis in patients with LCNEC. In this review article, we discuss treatment options for patients with LCNEC of the lung.

Identification of prognostic immunophenotypic features in cancer stromal cells of high-grade neuroendocrine carcinomas of the lung

PURPOSE

The immunophenotypes of cancer stromal cells have been recognized as prognostic factors of cancer. The purpose of this study was to analyze the prognostic markers of high-grade neuroendocrine carcinomas of the lung (HGNEC; both small cell carcinoma and large cell neuroendocrine carcinoma) by examining the immunophenotypes of cancer stromal cells.

MATERIALS AND METHODS

One hundred and fifteen patients who underwent a complete resection of HGNEC were included in this study. We examined the presence of CD204-positive tumor-associated macrophages (TAMs), Foxp3-positive regulatory T cells (Tregs), and podoplanin-positive cancer-associated fibroblasts (CAFs) to evaluate the prognostic values of these markers.

RESULTS

The number of CD204-positive TAMs and Foxp3-positive Tregs did not influence the overall survival (OS) or the relapse-free survival (RFS) of the patients. However, patients with podoplanin-positive CAFs had a significantly better prognosis than those with podoplanin-negative CAFs [OS: p = 0.002, RFS: p = 0.002, 5-year overall survival (5YR): 74 vs. 45 %]. According to subgroup analyses, patients with podoplanin-positive CAFs displayed a better prognosis for both small cell carcinoma (OS: p = 0.046, 5YR: 74 vs. 46 %) and large cell neuroendocrine carcinoma (OS: p = 0.020, 5YR: 74 vs. 45 %). Moreover, in multivariate analyses, the podoplanin status of the CAFs was shown to be a statistically significant independent predictor of recurrence.

CONCLUSION

The presence of podoplanin-positive CAFs had a favorable prognostic value, suggesting that the evaluation of podoplanin expression by CAFs would lead to a novel risk classification of patients.

[Pathological characteristic and clinical management of pulmonary carcinoid]

背景与目的

肺类癌采取以手术为主的多学科治疗，准确及时的病理诊断至关重要。本研究探讨肺类癌的病理特质，结合回顾性分析患者的转归预后，为临床决策提供依据。

方法

收集支气管肺内发生的类癌手术标本32例，回顾性分析患者相关的临床病理资料，系统研究病灶病理学表现与临床诊断和治疗效果的相关性。

结果

32例肺类癌患者中，典型类癌18例，不典型类癌14例；男女性别比为2.2:1；平均年龄（44±15）岁；近半数患者无症状；肿瘤最大径（3.1±1.3）cm；绝大多数为Ⅰ期患者（84.4%, 27/32），余Ⅱa期2例，Ⅲa期2例，Ⅳ期1例；随访时间为5.2年-9.7年；其中典型类癌随访15例，5年无进展生存率为100%；不典型类癌随访12例，5年无进展生存率为92.9%；肺类癌病理组织学的特质是典型的神经内分泌形态伴细胞角蛋白阳性，嗜铬素A、突触素和CD56等神经内分泌指标的表达，Ki-67指数的高低有助于鉴别诊断。

结论

肺类癌的病理鉴别诊断应结合相关酶标染色，积极争取手术是适宜的临床决策。

Clinicopathological features and the impact of the new TNM classification of malignant tumors in patients with pulmonary large cell neuroendocrine carcinoma

The prognosis of patients with large-cell neuroendocrine carcinoma (LCNEC) of the lung is extremely poor and the optimal treatment for these patients has yet to be determined. In this study, we described the clinicopathological characteristics of LCNECs and compared the prognoses of corresponding stages determined by the guidelines of the 6th and 7th editions of the TNM classification of malignant tumors. Clinical data from 42 patients diagnosed with primary LCNEC who underwent treatment at Kitasato University Hospital between 1991 and 2009 were retrospectively analyzed. On follow-up of 42 patients, 22 (52.4%) had confirmed recurrent tumors, including 8 patients with mediastinal lymph node recurrences and 19 with distant metastases. The sites of distant metastases included the brain in 8, bone in 8, liver in 7, lungs in 5 and adrenal glands in 4 patients. For all the patients, the 5-year overall survival rate was 34.7% and the 5-year disease-free survival rate was 32.9%. The 5-year overall survival rates of patients with stage I cancers according to the 6th and 7th staging editions was 51.3% (6th n=18, 7th n=16). Thirteen of 42 patients (31.0%) also had metachronous or synchronous primary cancers. Patients with LCNEC had poor outcomes, even those with stage I tumors classified according to the 7th edition of the TNM classification. Therefore, frequent recurrences in addition to metachronous or synchronous primary cancers in patients with LCNEC should be treated.

Large cell neuroendocrine carcinoma of the lung: is it possible to diagnose from biopsy specimens?

OBJECTIVE

We have recently proposed new diagnostic criteria for high-grade non-small cell neuroendocrine carcinoma, i.e. possible large cell neuroendocrine carcinoma, in biopsy specimens and have started a clinicopathological comparative study of high-grade neuroendocrine carcinomas in an advanced stage. This study aimed to elucidate the usefulness of our diagnostic criteria for inoperable advanced large cell neuroendocrine carcinoma and to know the true incidence of large cell neuroendocrine carcinoma among lung cancers.

METHODS

We reviewed all cancer lesions (1040 specimens) obtained by transbronchial lung biopsies in our hospital from 2002 to 2009 and selected 38 biopsy specimens that satisfied our diagnostic criteria for high-grade non-small cell neuroendocrine carcinoma. All 38 cases were clinicopathologically investigated and all biopsy specimens were precisely studied for their morphological characteristics.

RESULTS

Clinicopathological information about the selected 38 cases was very similar to the clinicopathological characteristics of large cell neuroendocrine carcinoma reported. Of 38 cases, six were at Stage I, II or IIIA, underwent surgery, and the diagnosis was confirmed to be large cell neuroendocrine carcinoma using surgical tumor specimens. In the 38 biopsy specimens, features of neuroendocrine morphology such as organoid nesting, peripheral palisading and rosette formation were not frequent histological features and the majority of tumor cells contained nuclei with a fine chromatin pattern. Mitoses were difficult to find; however, immunohistochemical Ki-67/MIB1 labeling indices were quite useful for evaluating proliferative activity, which ranged from 43.4 to 99.0%.

CONCLUSIONS

Our study showed the diagnostic potential of using biopsy specimens for large cell neuroendocrine carcinoma, and we herein proposed more simplified diagnostic criteria for possible large cell neuroendocrine carcinoma in practical diagnostic use.

Update on small cell carcinoma and its differentiation from squamous cell carcinoma and other non-small cell carcinomas

Small cell lung cancer (SCLC) comprises 14% of all lung cancers, and >30,000 new cases are diagnosed per year in the United States. SCLC is one of the most distinctive malignancies in the entire field of oncology with characteristic clinical properties, responsiveness to specific chemotherapy, genetic features and a highly reliable pathological diagnosis. SCLC is defined by light microscopy, and the most important stain is a good-quality hematoxylin and eosin (H&E)-stained section. The vast majority of cases can be diagnosed on H&E alone; however, in problem cases, immunohistochemistry can be very helpful in making the distinction from other tumors. Cytology is also a powerful tool, often being more definitive than small biopsies with scant tumor cells, crush artifact and/or necrosis. As virtually all SCLCs present in advanced stages, most patients are diagnosed based on small biopsy and cytology specimens. Historically, there has been significant evolution in the histological subclassification of SCLC dating from 1962 when Kreyberg proposed the oat cell and polygonal cell types. The current subclassification recognizes only two subtypes: pure SCLC and combined SCLC. Pathologists need to do their best to make a diagnosis of SCLC or other histological types of lung cancer and this can be achieved in most cases. This review will address some of the diagnostic problems that occur in the minority of cases and outline practical ways to address them. Brief reference will be made to other neuroendocrine lung tumors with an overview of the molecular pathogenesis of this spectrum of tumors.

Advances in neuroendocrine lung tumors

Pulmonary neuroendocrine (NE) tumors include a spectrum of tumors from the low-grade typical carcinoid (TC) and intermediate-grade atypical carcinoid (AC) to the high-grade large-cell neuroendocrine carcinoma (LCNEC) and small-cell carcinoma (SCLC). Nodular NE proliferations ≥ 0.5 cm are classified as carcinoid tumors and smaller ones are called tumorlets. When NE cell hyperplasia and tumorlets are extensive they represent the rare preinvasive lesion for carcinoids known as diffuse idiopathic pulmonary NE cell hyperplasia. Carcinoid tumors have significant clinical, epidemiologic and genetic differences from the high-grade SCLC and LCNEC. Multiple endocrine neoplasia type I can be found in TC and AC patients but not those with LCNEC and SCLC. Also both LCNEC and SCLC can demonstrate histologic heterogeneity with other major histologic types of lung carcinoma such as adenocarcinoma or squamous cell carcinoma, but is not characteristic of TC or AC. Genetic changes are very high in SCLC and LCNEC, but usually low for TC, intermediate for AC. The diagnosis of SCLC, TC and AC can be made by light microscopy without the need for special tests in most cases, but for LCNEC it is required to demonstrate NE differentiation by immunohistochemistry or electron microscopy.

Neuroendocrine tumors of the lung: an update

CONTEXT

The 2004 World Health Organization (WHO) classification recognizes 4 major types of lung neuroendocrine tumors: typical carcinoid, atypical carcinoid, small cell lung cancer, and large cell neuroendocrine carcinoma. Markedly different prognostic implications and treatment paradigms for these tumors underscore the importance of accurate pathologic diagnosis.

OBJECTIVE

To detail the clinical and pathologic features of lung neuroendocrine tumors, with emphasis on diagnostic criteria, differential diagnoses, and application of immunohistochemistry. The emerging evidence for the utility of Ki-67 (MIB1) in the diagnosis of lung neuroendocrine tumors, particularly in small biopsy and cytology, is emphasized.

DATA SOURCES

The 2004 WHO classification, other published literature, and primary material from the author's institution.

CONCLUSIONS

The current WHO classification of neuroendocrine tumors is based on morphologic features in combination with precisely defined mitotic rate and absence or presence of necrosis. Ki-67 (MIB1) is emerging as a useful ancillary tool in the diagnosis of these tumors. Continued research efforts are needed to identify additional immunohistochemical and molecular biomarkers that can serve as ancillary diagnostic tools and as potential therapeutic targets for these diseases.

High-grade neuroendocrine carcinoma of the lung: comparative clinicopathological study of large cell neuroendocrine carcinoma and small cell lung carcinoma

Large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC) are high-grade neuroendocrine carcinomas. In order to clarify the similarities and differences between these cancers, 22 cases each of LCNEC and SCLC were collected and a comparative pathological study was carried out. First, their clinicopathological characteristics were confirmed, which were very similar to those previously reported. The 5 year survival rate of LCNEC and SCLC patients was 38.3% and 29.7%, respectively. The morphological characteristics of LCNEC and SCLC were then reviewed with regard to the morphology previously used to differentiate these cancers. As a result, many morphological indicators, such as tumor cell size, nuclear/cytoplasmic ratio, nuclear molding, rosette formation, prominent nucleoli and karyolysis were confirmed to be significant indicators for distinguishing LCNEC from SCLC. On comparative immunohistochemistry, LCNEC had significantly high staining scores for the expression of keratin 7 and 18, E- and P-cadherins, beta-catenin, villin 1, retinoblastoma protein (pRB), c-met and alpha-enolase. These results might reflect the differentiation or deviation of LCNEC toward an epithelial nature irrespective of neuroendocrine tumor lineage. In conclusion, the present comparative study of LCNEC and SCLC defined the similarities and differences between these cancers, and showed the biologically and clinicopathologically overlapping spectrum of the tumor lineage.

A long-term survivor with pulmonary large-cell neuroendocrine carcinoma

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) has been characterized by highly aggressive behavior, with early spread to both regional lymph nodes and distant sites and a rapidly fatal course. In fact, no reports have described an advanced pulmonary LCNEC patient who has had long-term survival. A patient with large-sized pulmonary LCNEC, who is free of disease 11 years after surgery and postoperative chemotherapy, was reported.

Pulmonary large cell neuroendocrine carcinoma: its place in the spectrum of pulmonary carcinoma

In 1999, the World Health Organization categorized large cell neuroendocrine carcinoma (LCNEC) as a variant of large cell carcinoma. The World Health Organization categorization not only classified histologic types of large cell carcinomas of the lung in detail, but also revealed that histologic subtypes of lung carcinomas were closely related to the prognosis of patients with those carcinomas. Large cell neuroendocrine carcinomas are common tumors that are now more frequently diagnosed by pathologists as recognition of LCNEC improves. Since the first report of LCNEC in 1991, many authors have reported that LCNECs are aggressive tumors and that patients with LCNECs have a very poor prognosis. Although LCNEC is categorized as a variant of large cell carcinoma, the biological behaviors of LCNEC tumors resemble those of small cell lung carcinomas, and LCNEC reveals the feature of a high-grade neuroendocrine tumor. Because patients with LCNEC have a poor prognosis, surgery alone is not sufficient. Multimodality therapies (including adjuvant chemotherapy) appear to be promising for the improvement of the prognosis in patients with LCNEC, even if the pathologic stage is IA, and should be evaluated further in larger multi-institutional trials.

Prospective study of adjuvant chemotherapy for pulmonary large cell neuroendocrine carcinoma

BACKGROUND

Patients with pulmonary large cell neuroendocrine carcinoma (LCNEC) have a very poor prognosis, but the benefit of adjuvant chemotherapy for these patients has not been established. We performed a prospective analysis of adjuvant chemotherapy for patients with completely resected pulmonary LCNECs to assess the effect of adjuvant chemotherapy.

METHODS

The adjuvant mixture consisted of cisplatin and VP-16 and was administered after surgery to 15 patients with LCNECs from 2000 to 2005. We compared patient survival with historical data for LCNEC patients treated without platinum-based adjuvant chemotherapy after surgery.

RESULTS

There were no differences in age, gender, surgical methods, and staging between the adjuvant chemotherapy group and the control group. Median follow-up was 33 months for the adjuvant group and 42 months for the control group. Of the 15 patients in the adjuvant chemotherapy group, 2 patients had disease recurrence and 1 died of interstitial pneumonia. The overall survival rate at 2 and 5 years of patients with adjuvant chemotherapy was 88.9%. The overall survival rate between patients with adjuvant chemotherapy and the historical control group was significantly different.

CONCLUSIONS

Adjuvant chemotherapy consisting of cisplatin and VP-16 after surgery appears promising for the improvement of the prognosis for patients with completely resected LCNECs, and it should be evaluated further in larger multi-institutional trials.

Prognostic impact of large cell neuroendocrine histology in patients with pathologic stage Ia pulmonary non-small cell carcinoma

BACKGROUND

Most patients with pathologic stage Ia non-small cell lung carcinoma have a good prognosis, and adjuvant chemotherapy is currently not being used in the management of this stage of the disease. However, if significant negative prognostic factors become evident in patients with pathologic stage Ia non-small cell lung carcinoma, patients with negative prognostic factors should have adjuvant treatment after surgery.

METHODS

We analyzed 335 cases of pathologic stage Ia non-small cell lung carcinoma treated between 1988 and 2003 by complete resection. The pathologic stage Ia non-small cell lung carcinomas comprised 259 adenocarcinomas, 65 squamous cell carcinomas, and 11 large cell neuroendocrine carcinomas. The prognostic impact of various clinical variables was investigated by the Cox proportional hazards multivariable regression model.

RESULTS

Univariate analysis showed that large cell neuroendocrine carcinoma histology, old age, large tumor size, male gender, and smoking predicted poorer overall survival. Large cell neuroendocrine carcinoma had a significantly poorer prognosis than other non-small cell carcinomas. Multivariate analysis revealed that large cell neuroendocrine carcinoma was predictive of poorer overall survival (P = .0200, hazard ratio 2.787).

CONCLUSIONS

Large cell neuroendocrine histology has a significant adverse prognostic impact on pathologic stage Ia non-small cell carcinoma. Therefore, surgical resection alone represents insufficient treatment for large cell neuroendocrine carcinoma, even for pathologic stage Ia disease.

Neuroendocrine differentiation and neuroendocrine morphology as two different patterns in large-cell bronchial carcinomas: outcome after complete resection

BACKGROUND

In 1999, large-cell neuroendocrine carcinoma of the lung was introduced by the World Health Organization (WHO) as a new tumor entity in the group of non-small cell, epithelial tumors, a differentiated classification of neuroendocrine tumors of the lung not existing until this time. Scientific knowledge on prognosis and therapy of these tumors, especially between those with neuroendocrine morphology only and those showing additional expression of neuroendocrine markers, is fragmentary. In this analysis, we studied the clinical behavior and the prognosis of these two rare tumor entities.

PATIENTS AND METHODS

The analysis comprises 12 patients of a total of 2053, who underwent thoracotomy for non small-cell lung carcinoma between 1997 and 2005 in the Department of Thoracic Surgery at the University Hospital of Freiburg. Clinical data, pathological examinations as well as complete follow-up were reviewed from large-cell carcinoma with neuroendocrine morphology only (n=4) and from large-cell carcinoma expressing neuroendocrine markers (n=8).

RESULTS

The median survival of patients with neuroendocrine morphology was 30 months (11-96 months). In the patient group showing the expression of neuroendocrine markers, the median survival time was 20 months (2-26 months). Tumor recurrences occurred in the group with neuroendocrine morphology, without exception, in the form of distant metastases and in the group with neuroendocrine markers as intrapulmonary metastases.

CONCLUSION

Large-cell neuroendocrine carcinomas of the lung show aggressive behavior with a poor prognosis. Expression of neuroendocrine markers markedly reduce tumor-free interval as well as survival and might influence the site of metastases.

Large-Cell Neuroendocrine Carcinoma of the Lung: An Aggressive Neuroendocrine Lung Cancer

Large cell neuroendocrine carcinoma (LCNEC) is part of the neuroendocrine spectrum of pulmonary tumors. This increasingly recognized tumor has been reported to have 5-year actuarial survival rates following resection that are worse than those described for other variants of non-small cell lung cancer (NSCLC). Therefore, debate has emerged regarding whether the tumors should be classified and treated as NSCLC or small-cell lung cancer. This article reviews the tumor characterization, biology, presentation and diagnosis, surgical therapy, results of therapy, and long term prognosis of patients with LCNEC.

Characteristics of loss of heterozygosity in large cell neuroendocrine carcinomas of the lung and small cell lung carcinomas

Large cell neuroendocrine carcinoma (LCNEC) of the lung is a new entity. Besides morphological characteristics, its molecular biological features have been investigated by many researchers and compared to those of other neuroendocrine carcinomas, small cell lung carcinoma (SCLC) and carcinoid tumor (CT). However, there are few reports that show the significantly different genetic characteristics between them. The purpose of the present paper was to study the frequency of loss of heterozygosity (LOH) at chromosome 3p (3p14.2) in 38 neuroendocrine carcinomas of the lung (13 LCNEC, 11 SCLC and 14 CT) and 10 large cell carcinomas (LCC). The frequencies of LOH at 3p14.2 were 69.2% in LCNEC, 81.8% in SCLC, 50.0% in LCC and 7.14% in CT. Those at 22q13.3 were 30.8% in LCNEC, 72.7% in SCLC, 45.5% in LCC and 7.14% in CT. In particular, the frequency of SCLC with LOH at both 3p14.2 and 22q13.3 (63.6%) was significantly higher than that of LCNEC (15.4%). LCNEC and SCLC had different characteristics of LOH patterns at 3p14.2 and 22q13.3. The combined analysis of the LOH at 3p14.2 and 22q13.3 is thought to be useful for differential diagnosis between LCNEC and SCLC.

Subcentimeter large cell neuroendocrine carcinoma of the lung

To our knowledge, no report exists of a subcentimeter size large cell neuroendocrine carcinoma (LCNEC) of the lung. A 75-year-old man participating in a low-dose CT screening program for lung cancer was found incidentally to have a partly-solid nodule in the right upper lung. After treatment with antibiotics, a repeat CT showed resolution of the nodule, but a new solid nodule measuring 9 x 9 mm was detected in the left lower lobe. The lesion showed marked enhancement on dynamic contrast-enhanced MRI. Video-assisted thoracic surgery and frozen section biopsy was suggestive of malignant lesion, resulting in extension of surgery to lobectomy with nodal dissection. The final diagnosis was stage IA-LCNEC. The estimated volume doubling time of the tumor was 30.1 days. These aggressive tumors may rarely have doubling times that overlap with benign processes.

Role of chemotherapy and the receptor tyrosine kinases KIT, PDGFRalpha, PDGFRbeta, and Met in large-cell neuroendocrine carcinoma of the lung

PURPOSE

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a relatively uncommon, high-grade neuroendocrine tumor sharing several features with small-cell lung carcinoma (SCLC) but currently considered as a variant of non-SCLC and accordingly treated with poor results. Little is known about the optimal therapy of LCNEC and the possible therapeutic molecular targets.

PATIENTS AND METHODS

We reviewed 83 patients with pure pulmonary LCNEC to investigate their clinicopathologic features, therapeutic strategy, and immunohistochemical expression and the mutational status of the receptor tyrosine kinases (RTKs) KIT, PDGFRalpha, PDGFRbeta, and Met.

RESULTS

LCNEC histology predicted a dismal outcome (overall median survival, 17 months) even in stage I patients (5-year survival rate, 33%). LCNEC strongly expressed RTKs (KIT in 62.7% of patients, PDGFRalpha in 60.2%, PDGFRbeta in 81.9%, and Met in 47%), but no mutations were detected in the exons encoding for the relevant juxtamembrane domains. Tumor stage and size (> or = 3 cm) and Met expression were significantly correlated with survival. At univariate and multivariate analysis, SCLC-based chemotherapy (platinum-etoposide) was the most important variable correlating with survival, both in the adjuvant and metastatic settings (P < .0001).

CONCLUSION

Pulmonary LCNEC represents an aggressive tumor requiring multimodal treatment even for resectable stage I disease, and LCNEC seems to respond to adjuvant platinum-etoposide-based chemotherapy. Patients who received this therapy had the best survival rate. Despite our failure in finding mutational events in the tested RTKs, the strong expression of KIT, PDGFRalpha, PDGFRbeta, and Met in tumor cells suggests an important role of these RTKs in LCNEC, and these RTKs seem to be attractive therapeutic targets.

Large cell neuroendocrine carcinoma: An aggressive form of non-small cell lung cancer

OBJECTIVE

Large cell neuroendocrine carcinomas of the lung display morphologic and immunohistochemical characteristics common to neuroendocrine tumors and the morphologic features of large cell carcinomas. Surgical resection of large cell neuroendocrine carcinomas in many series has been described, with 5-year actuarial survivals ranging from 13% to 57%. Considerable debate has emerged as to whether these tumors should be classified and treated as non-small cell lung cancers or small cell lung cancers. The objective of this study was to report the outcome of surgical resection in patients with large cell neuroendocrine carcinomas.

METHODS

An analysis of our tumor registry was performed to identify all patients undergoing surgical resection of lung cancer between July 1, 1988, and December 31, 2002, for large cell tumors. Cases were then segregated into large cell neuroendocrine carcinomas, mixed large cell neuroendocrine carcinomas (in which at least one portion of the tumor was a large cell neuroendocrine carcinoma), or large cell carcinomas on the basis of morphology and differentiation. Follow-up was complete on all patients, with a mean follow-up of 48 months. Type of resection, mortality, and survival by stage were analyzed. Kaplan-Meier survival was determined for all patients from the date of surgical intervention. Cox proportional hazards model analysis incorporating the variables of age, sex, histology, and stage estimated the effect of large cell neuroendocrine carcinomas and mixed large cell neuroendocrine carcinomas on recurrence and death. The stage of disease in all patients was assessed according to the 1997 American Joint Committee on Cancer guidelines.

RESULTS

Of the 2099 patients who underwent resection, 82 (3.9%) had large cell lung cancers. Perioperative mortality was 2.4%. Overall survival and freedom from recurrence at 5 years for the entire group was 47.1% and 58.4%, respectively. Overall survival by histologic subtype at 5 years was 30.2% for patients with large cell neuroendocrine carcinomas (n = 45), 30.3% for patients with mixed large cell neuroendocrine carcinomas (n = 11), and 71.3% for patients with large cell carcinomas (n = 21). Survival was significantly worse for patients with large cell neuroendocrine carcinomas than for patients with large cell carcinomas ( P = .013). The presence of large cell neuroendocrine carcinomas in the specimen (the large cell neuroendocrine carcinoma and mixed large cell neuroendocrine carcinoma groups combined) was significantly associated with decreased survival (relative risk, 2.44; 95% confidence interval 1.29-4.58; P = .003) and decreased freedom from recurrence (relative risk, 4.52; 95% confidence interval, 1.76-11.57; P < .001).

CONCLUSION

Patients with large cell neuroendocrine carcinomas have a significantly worse survival after resection than patients with large cell carcinomas, even in stage I disease. Accurate differentiation of large cell neuroendocrine carcinoma from large cell carcinoma is important because it identifies those patients at highest risk for the development of recurrent lung cancer.