Pulmonary large cell carcinomas with neuroendocrine features are high-grade neuroendocrine tumors

Prognostic significance of YAP1 expression and its association with neuroendocrine markers in resected pulmonary large cell neuroendocrine carcinoma (LCNEC)

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It is the first study to determine the prognostic relevance of YAP1 in pulmonary LCNEC. And we found YAP1 is a prognostic factor for worse survival, especially for DFS.

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We investigated the relationship between YAP1 and NE markers (INSM1, DLL3, NeuroD1) and found that YAP1 expression was negatively correlated with INSM1 and DLL3, but not significantly correlated with NeuroD1.

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Our sample size is large and the clinical data is complete.

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The exploration of the prognostic mechanism of LCNEC is of great significance to its subtype classification and stratification of treatment and prognosis.

Background

YAP1 (Yes-associated protein 1), an important effector of the Hippo pathway, acts as an oncogene and is overexpressed in various malignant tumors. However, the function and expression pattern of YAP1 in pulmonary large cell neuroendocrine carcinoma (LCNEC) have not been systematically established. This study aimed to explore the relationship between YAP1 expression and neuroendocrine differentiation markers and their prognostic significance in LCNEC.

Materials and methods

YAP1 protein and neuroendocrine markers (INSM1, NeuroD1 and DLL3) expression were examined by immunohistochemical (IHC) staining in 80 resected pulmonary LCNEC cases. The possible association between these markers and clinicopathological features was evaluated and survival analyses were performed.

Results

YAP1 was highly expressed in 25% LCNECs (20/80) , especially at a relatively higher T stage (p = 0.015). YAP1 expression was negatively correlated with INSM1 (χ²=11.53, p = 0.001) and DLL3(χ²=8.55, p = 0.004), but not with NeuroD1 (p = 0.482). For survival analyses, YAP1 expression was associated with worse disease-free survival (DFS) and overall survival (OS) (median DFS: 13 months vs. not reached (NR), p = 0.0096; median OS: not reached, NR vs. NR, p = 0.038), and was an unfavorable prognostic factor for DFS (HR:3.285; 95%CI: 1.526-7.071, p = 0.002) and OS (HR: 2.864, 95% CI: 0.932-8.796, p = 0.066).

Conclusions

YAP1 was found to be conversely correlated with neuroendocrine markers and a prognostic factor for worse survival in resected LCNEC patients, and mechanisms need to be further investigated.

A Novel Strategy for the Diagnosis of Pulmonary High-Grade Neuroendocrine Tumor

Correctly diagnosing a histologic type of lung cancer is important for selecting the appropriate treatment because the aggressiveness, chemotherapy regimen, surgical approach, and prognosis vary significantly among histologic types. Pulmonary NETs, which are characterized by neuroendocrine morphologies, represent approximately 20% of all lung cancers. In particular, high-grade neuroendocrine tumors (small cell lung cancer and large cell neuroendocrine tumor) are highly proliferative cancers that have a poorer prognosis than other non-small cell lung cancers. The combination of hematoxylin and eosin staining, Ki-67, and immunostaining of classic neuroendocrine markers, such as chromogranin A, CD56, and synaptophysin, are normally used to diagnose high-grade neuroendocrine tumors; however, they are frequently heterogeneous. This article reviews the diagnostic methods of lung cancer diagnosis focused on immunostaining. In particular, we describe the usefulness of immunostaining by Stathmin-1, which is a cytosolic phosphoprotein and a key regulator of cell division due to its microtubule depolymerization in a phosphorylation-dependent manner, for the diagnosis of high-grade neuroendocrine tumors.

Comparative Study of Pulmonary Combined Large-Cell Neuroendocrine Carcinoma and Combined Small-Cell Carcinoma in Surgically Resected High-Grade Neuroendocrine Tumors of the Lung

Objectives

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung cancer (SCLC) are both classified as pure and combined subtypes. Due to the low incidence and difficult diagnosis of combined LCNEC (C-LCNEC) and combined SCLC (C-SCLC), few studies have compared their clinical features and prognosis.

Materials and Methods

We compared the clinical features, mutation status of driver genes (EGFR, ALK, ROS1, KRAS, and BRAF), and prognosis between C-LCNEC and C-SCLC. Univariate and multivariate Cox regression analyses were applied for survival analysis.

Results

We included a total of 116 patients with C-LCNEC and 76 patients with C-SCLC in the present study. There were significant differences in distribution of smoking history, tumor location, pT stage, pN stage, pTNM stage, visceral pleural invasion (VPI), and combined components between C-LCNEC and C-SCLC (P<0.05 for all). C-SCLC was more advanced at diagnosis as compared to C-LCNEC. The incidence of EGFR mutations in C-LCNEC patients was higher than C-SCLC patients (25.7 vs. 5%, P=0.004). We found that tumor size, pN stage, peripheral CEA level, and adjuvant chemotherapy were independently prognostic factors for DFS and OS in C-LCNEC patients, while peripheral NSE level, pT stage, pN stage, VPI and adjuvant chemotherapy were independently associated with DFS and OS for C-SCLC patients (P<0.05 for all). Propensity score matching with adjustment for the confounders confirmed a more favorable DFS (P=0.032) and OS (P=0.019) in patients with C-LCNEC in comparison with C-SCLC patients upon survival analysis.

Conclusions

The mutation landscape of driver genes seemed to act in different way between C-SCLC and C-LCNEC, likely by which result in clinical phenotype difference as well as better outcome in C-LCNEC.

Characteristics of Patients with Large-Cell Neuroendocrine Carcinoma of the Lung

OBJECTIVES

Neuroendocrine tumors of the lungs are a clearly different group of tumors with definite ultrastructural, immunohistochemical, and molecular features. We reported and analyzed the incidence, clinicopathological features, surgery rates, responses to first-line therapy, and survival outcomes of this rare condition according to our lung cancer patient database.

MATERIALS AND METHODS

We retrospectively collected the data of 62 patients who were histopathologically diagnosed with large cell neuroendocrine carcinoma of lung (LCNEC) between January 2010 and January 2016.

RESULTS

The patients were predominantly (95%) men (male:female=59:3) with their average age being 60.3±8.6 years. Diagnosis was made by the fine-needle aspiration biopsy (NAB) in 7 patients, bronchoscopic transbronchial biopsy in 13, and surgery in 42. Nearly 43.5% of the patients presented with the tumor in the right upper lobe. Additionally, tumors of 46.8% patients could be observed in peripheral locations. Sixteen patients presented with stage 1, 17 with stage 2, 15 with stage 3, and 14 with stage 4. Median progression-free survival (PFS) was 29 months (SE: 12.2) (95% CI, 5.2-52.8 months). Progression-free survival (PFS) was significantly better in patients with low N, M0, early stage, p63 positive, and TTF-1 positive across the entire cohort. Overall survival (OS) was significantly better in patients with comparatively lower N, M0, low stage, and peripheral location.

CONCLUSION

This study demonstrated a single-center experience with clinicopathologic factors and survival outcomes of LCNEC patients.

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.

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

Background

The aim of this study was to identify subgroups with good or bad prognosis in patients with pulmonary large cell neuroendocrine carcinoma (LCNEC) based on immunostaining patterns with neuroendocrine markers and compare them with small cell lung carcinoma (SCLC).

Methods

From January 2001 to December 2017, of all patients with resected LCNEC and SCLC, we selected patients whose pathological tumor sizes were ≤30 mm in diameter (defined as small‐sized tumors) and who underwent complete resection with lymphadenectomy. We classified patients with small‐sized LCNEC (sLCNEC) into two subgroups based on immunostaining patterns with three neuroendocrine markers (chromogranin A, synaptophysin, and NCAM) and compared them to small‐sized SCLC (sSCLC).

Results

A total of 48 patients with sLCNEC and 39 patients with sSCLC were enrolled. Of 48 patients with sLCNEC, 21 were categorized as the small‐sized triple‐positive group (sTP), whose patients were positive for the three neuroendocrine markers, and 27 patients were categorized as the small‐sized nontriple‐positive group (sNTP), whose patients were not positive for all three neuroendocrine markers. The percentage of lymph node metastasis was significantly lower in sNTP than in sTP and sSCLC. There was no significant difference in overall survival, but recurrence‐free survival (RFS) and tumor‐specific survival (TSS) were significantly poorer in sTP and sSCLC than in sNTP. Multivariate analysis revealed sTP and sSCLC were independent prognostic factors for poorer RFS and TSS than those of sNTP.

Conclusions

The sNTP subgroup had a good prognosis and the sTP subgroup a poor prognosis. There were some similarities in clinicopathological features between sTP and sSCLC.

Successful treatment with temozolomide in an elderly woman with advanced pulmonary large-cell neuroendocrine carcinoma: A case report

RATIONALE

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is a rare type of lung cancer, and 40% of patients are in stage IV at initial diagnosis. It has an extremely poor prognosis with a 1-year survival rate of 27%. Patients with LCNEC are predominantly male, older, and heavy smokers. There has been no clinical trial conducted to determine the best treatment for advanced LCNEC. Temozolomide (TMZ) has been successfully used to treat a variety of malignancies, such as glioblastoma multiforme, astrocytoma, non-small-cell lung carcinoma. However, its efficacy in advanced stage pulmonary LCNEC has rarely been studied.

PATIENT CONCERNS

We present the rare case of a 69-year-old woman with advanced pulmonary LCNEC. She complained of recurrent dry cough for more than 1 month.

DIAGNOSES

After chest computed tomography (CT) and biopsies of supraclavicular lymph nodes, the diagnosis of stage IIIB LCNEC of the lung was made.

INTERVENTIONS

Four cycles of chemotherapy with etoposide and cisplatin was administered as the first-line regimen. As the disease progressed, we administered icotinib and liposomal paclitaxel. Finally, we administrated TMZ as the third-line regimen.

OUTCOMES

The patient showed partial response after 5 months. She has survived for 19 months from the time of diagnosis with a good performance status.

LESSONS

TMZ appears to be an efficacious option to treat elderly patients with advanced LCNEC.

Perioperative chemotherapy with pemetrexed and cisplatin for pulmonary large-cell neuroendocrine carcinoma: a case report and literature review

Background

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is associated with poor prognosis, and its treatment strategy is still controversial, especially regarding chemotherapy regimens.

Case report

We present the case of a 49-year-old Chinese male with primary pulmonary LCNEC treated with neoadjuvant and adjuvant chemotherapy with cisplatin plus pemetrexed. A suspected quasi-circular mass in the left lower pulmonary lobe and an enlarged mediastinal lymph node were found. The patient was diagnosed with adenocarcinoma with neuroendocrine differentiation based on computerized tomography-guided percutaneous lung biopsy. An EGFR gene mutation test showed negative results. Cisplatin and pemetrexed were administered as the neoadjuvant chemotherapy regimen. The primary lesion had reduced markedly, and the enlarged mediastinal lymph node had disappeared after two cycles of neoadjuvant chemotherapy. A left lower lobectomy and mediastinal lymph node dissection were performed. The lesion was confirmed as LCNEC based on postoperative histopathological analysis and immunohistochemical results. The patient underwent four cycles of adjuvant chemotherapy with cisplatin and pemetrexed for a month postoperatively, followed by postoperative adjuvant radiotherapy. The patient was still alive after a follow-up of 24 months, with no evidence of tumor recurrence.

Conclusion

Cisplatin combined with pemetrexed is effective and safe for patients with pulmonary LCNEC.

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.

The Role of Systemic Therapy in the Management of Stage I Large Cell Neuroendocrine Carcinoma of the Lung

INTRODUCTION

The optimal treatment strategy for resected stage I large cell neuroendocrine carcinoma of the lung (LCNEC) remains unknown. In this analysis, we evaluate the impact of systemic chemotherapy on patients with stage I LCNEC who have undergone surgical resection.

METHODS

The study population included patients who underwent surgical resection for LCNEC and had pathologic stage I disease. We compared overall survival between patients who underwent surgical resection alone and those who underwent surgical resection plus chemotherapy. Overall survival was estimated by the Kaplan-Meier method, and comparisons were analyzed by using multivariable Cox models and propensity score-matched analyses.

RESULTS

From 2004 to 2013, 1232 patients underwent surgical resection for stage I LCNEC in the National Cancer Database, including 957 patients (77.7%) who underwent surgical resection alone and 275 (22.3%) who received both surgery and systemic chemotherapy. Five-year survival was significantly improved in patients who received chemotherapy (64.5% versus 48.4% [hazard ratio =0.54, 95% confidence interval: 0.43-0.68, p < 0.001]). Multivariable Cox modeling confirmed the survival benefit from chemotherapy for patients with resected stage I LCNEC (hazard ratio = 0.54, 95% confidence interval: 0.43-0.68, p <0.0001). The survival benefit was further confirmed by propensity-matched analysis. In addition, older (age >70 years), comorbid white patients who underwent sublobar resections for tumors larger than 20 mm had worse survival outcomes.

CONCLUSION

In this largest-reported retrospective study of patients with resected stage I LCNEC, survival was improved in patients who received chemotherapy in both stage IA and stage IB LCNEC.

Update on large cell neuroendocrine carcinoma

High-grade neuroendocrine carcinomas of the lung are classified into two categories: large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC). While typical cases of LCNEC are morphologically distinct from SCLC, the differentiation between LCNEC and SCLC can be challenging in some cases. In fact, there are borderline high-grade neuroendocrine carcinomas that morphologically fall between LCNEC and SCLC. Growing evidence suggests that LCNEC is a histologically and biologically heterogeneous group of tumors. Molecular profiling with next-generation sequencing (NGS) has revealed a few biologically distinct subsets of LCNEC. Of those, the SCLC-like subset is characterized by concurrent inactivating mutations in TP53 and loss of RB1 that are typically seen in SCLC, whereas the non-small cell lung cancer (NSCLC)-like subset frequently harbors molecular alterations that are usually seen in NSCLC. Furthermore, the SCLC-like subset exhibits morphologic features of SCLC, and NSCLC-like morphology predominates in the NSCLC-like subset, although there was a substantial overlap in morphologic features between these subsets. As for the treatment of LCNEC, surgery is advocated for early stage tumors, but surgery alone does not appear to be sufficient and adjuvant chemotherapy, consisting of platinum/etoposide, likely prevents recurrence in patients with completely resected LCNEC. For advanced disease, there have been conflicting reports as to whether LCNEC responds to chemotherapeutic regimens in the similar manner to SCLC rather than NSCLC, and the heterogeneous biology of LCNEC may contribute in part to the discrepant results. A further understanding of the biology of LCNEC will lead to novel approaches to clinical managements of patients with LCNEC.

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.

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.

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.

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.

Small cell carcinoma of the lung and large cell neuroendocrine carcinoma interobserver variability

AIMS

To test the hypothesis that the published morphological criteria permit reliable segregation of small cell carcinoma of the lung (SCLC) and large cell neuroendocrine carcinoma (LCNEC) cases by determining the interobserver variation.

METHODS AND RESULTS

One hundred and seventy cases of SCLC, LCNEC and cases diagnosed as neuroendocrine lung carcinoma before LCNEC had been established as a diagnostic category were retrieved from the archives of the assessor's institutes. A representative haematoxylin and eosin section from each case was selected for review. Batches of cases were circulated among nine pathologists with a special interest in pulmonary pathology. Participants were asked to classify the cases histologically according to the 2004 World Health Organization (WHO) criteria. The diagnoses were collected and kappa values calculated. Unanimity of diagnosis was achieved for only 20 cases; a majority diagnosis was reached for 115 cases. In 35 cases no consensus diagnosis could be reached. There was striking variability amongst assessors in diagnosing SCLC and LCNEC. The overall level of agreement for all cases included in this study was fair (kappa=0.40).

CONCLUSIONS

Using non-preselected cases, the morphological WHO criteria for diagnosing SCLC and LCNEC leave room for subjective pathological interpretation, which results in imprecise categorization of SCLC and LCNEC cases.

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.

Neuroendocrine carcinomas of the lung: a critical analysis

Neuroendocrine carcinomas represent an important group of primary neoplasms in the lung. During the last decades, the nomenclature of these tumors has evolved and the current use of immunohistochemical and molecular biology studies have, to some extent, expanded the conventional view of these tumors. However, the primary diagnosis of most of these lesions is performed on limited biopsy specimens, which may not translate well when one is confronted with a nomenclature that is based on resected material. In addition, for some of these specific entities, some confusion and controversy apparently remain, allowing for the proliferations of different terms that, although they may be dismissed as "semantics," may have a role in interpretation, further subclassification, and, possibly, treatment. Herein we review current concepts regarding the classification of these neoplasms and the role of this classification in our daily practice and discuss how it may impact treatment.

[Trends in prognostic factors for neuroendocrine lung tumors]

OBJECTIVE

The aim of this study was to analyze trends in a variety of prognostic factors for neuroendocrine lung carcinomas through analysis of 2 groups of surgically treated patients.

PATIENTS AND METHODS

Group A contained the first 361 patients, treated between 1980 and 1997. That group was analyzed retrospectively and contained 261 patients with typical carcinoid tumors, 43 with atypical carcinoid tumors, 22 with large-cell neuroendocrine carcinoma, and 35 with small-cell neuroendocrine carcinoma. Group B contained 404 patients enrolled prospectively between 1998 and 2002: 308 with typical carcinoid tumors, 49 with atypical carcinoid tumors, 18 with large-cell neuroendocrine carcinoma, and 29 with small-cell neuroendocrine carcinoma. The following clinical variables were considered: sex, mean age, tumor site, tumor size, lymph node involvement, stage, metastasis, and local recurrence. The 1997 TNM classification was used for staging of lung cancer and survival analysis was performed along with assessment of factors influencing survival. Statistical analysis of the data involved univariate and multivariate analysis.

RESULTS

In both groups, significant differences were observed between patients with typical and atypical carcinoid tumors in terms of mean age, tumor size, node involvement, and recurrence. In group A, female sex, node involvement, and recurrence differed between patients with atypical carcinoid tumors and those with large-cell neuroendocrine carcinoma; the same was true for group B, with the exception of lymph node involvement. Node involvement differed between patients with small-cell versus large-cell neuroendocrine carcinoma in group A but not group B. Both groups displayed significant differences in overall survival and survival of patients with lymph node involvement between patients with typical and atypical carcinoid tumors and between patients with atypical carcinoid tumors and those with large-cell neuroendocrine carcinoma; no differences were observed between patients with large-cell versus small-cell neuroendocrine carcinoma. Histological type and lymph node involvement had the greatest influence on prognosis in the multivariate analysis.

CONCLUSIONS

A well-defined trend is observed in prognostic factors for neuroendocrine lung tumors. Histological type and lymph node involvement show the greatest influence on survival.

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.

p53 immunostaining is correlated with reduced survival and is not correlated with gene mutations in resected pulmonary large cell carcinomas

Malignancy of pulmonary large cell carcinomas (LCC) increases from classic LCC through LCC with neuroendocrine morphology (LCCNM) to large cell neuroendocrine carcinomas (LCNEC). However, the histological classification has sometimes proved to be difficult. Because the malignancy of LCC is highly dependent on proteins with functions in the cell cycle, DNA repair, and apoptosis, p53 has been targeted as a potentially useful biological marker. p53 mutations in lung cancers have been shown to result in expression and protein expression also occurs in the absence of mutations. To validate the importance of both p53 protein expression (by immunostaining) and p53 gene mutations in lung LCC (by PCR-single strand conformational polymorphism analysis of exons 5, 6, 7, and 8) and to study their relationships with clinical factors and sub-classification we investigated the correlation of p53 abnormalities in 15 patients with LCC (5 classic LCC, 5 LCNEC, and 5 LCCNM) who had undergone resection with curative intent. Of these patients, 5/15 expressed p53 and none had mutant p53 sequences. There was a negative survival correlation with positive p53 immunostaining (P = 0.05). After adjustment for stage, age, gender, chemotherapy, radiotherapy, and histological subtypes by multivariate analysis, p53 expression had an independent impact on survival. The present study indicates that p53 assessment may provide an objective marker for the prognosis of LCC irrespective of morphological variants and suggests that p53 expression is important for outcome prediction in patients with the early stages of LCC. The results reported here should be considered to be initial results because tumors from only 15 patients were studied: 5 each from LCC, LCNEC and LCCNM. This was due to the rarity of these specific diseases.

Pulmonary and extrapulmonary poorly differentiated large cell neuroendocrine carcinomas

BACKGROUND

Poorly differentiated large cell neuroendocrine carcinomas (LCNEC) comprise a rare and still scarcely known subgroup of neuroendocrine tumors. The objective of this study was to investigate the epidemiology, clinical presentation, prognostic factors, and molecular pathways of patients with poorly differentiated LCNEC.

METHODS

Forty-one patients who had a confirmed diagnosis of poorly differentiated LCNEC according to the criteria of the most recent World Health Organization classification of neuroendocrine tumors of the lung entered the study. The clinicopathologic features of patients with poorly differentiated LCNEC were reviewed, prognostic parameters for their survival were studied, and the prognostic roles of the proteins involved in cell cycle regulation were investigated with tissue array analysis in a subset of patients with LCNEC.

RESULTS

Twenty-four men and 17 women with a median age of 63 years (age range, 26-81 years) who had LCNEC were studied. LCNEC developed after therapy for a first cancer in 14% of patients. Neither a personal or familial history of endocrine tumors nor a primary association that was compatible with an inherited syndrome was observed. The increase of at least 1 serum biologic marker was observed in 93% of patients. A primary tumor was identified in only 63% patients. Thirty-one patients had distant metastases, and 10 patients had only lymph node metastases at the time of the diagnosis. The 5-year survival rate was 24%. High mitotic count, low expression of neuroendocrine markers, and a Bcl-2/Bax ratio > 1 were unfavorable prognostic factors for survival (P < .01). All patients who had isolated peripheral lymph node LCNEC achieved a cure.

CONCLUSIONS

The results from this study highlighted distinctive clinical features and prognostic indicators of poorly differentiated LCNEC. Peripheral isolated lymph node clinical presentation is proposed as a new clinical entity.

Neuroendocrine differentiation as a survival prognostic factor in advanced non-small cell lung cancer

Beckground/Aim. Neuroendrocine lung tumors are histologically heterogenous group of cancers with different clinical progression. In non-small cell lung cancer (NSCLC) neuroendocrine differentiation exists in 10-30% of patients. The aim of this study was to determine the frequency and influence of neuroendocrine differentiation on survival of treated patients with advanced non-small cell lung cancer (NSCLC). Methods. A clinical trial included 158 patients (74% males and 26% females), with the diagnosis of NSCLC, determined by histological verification. The patients were treated by combined chemo - and X-ray therapy in stage III (without pleural effusion) or chemotherapy only in stage III (with pleural effusion) and stage IV. Chemotherapy was conducted until progression of the disease, but no more than six cycles. When the progression had been noted in stage III (without pleural effusion), the treatment was continued with X-ray therapy. Neuron specific enolase, chromogranin A, as well as synapthophysin expression in tissue examples were determined by immunohistochemical analysis with monoclonal mouse anti-human-bodies. Survival was assessed within a year and two years follow-up examination. Results. A total of 53 patients (34%) had NSCLC with neuroendocrine differentiation, confirmed rather in large cell lung cancer and lung adenocarcinoma (66.7% and 40%, respectively). Neuron specific enolase, chromogranin A and synapthophysin expression was noted in 45 (28.5%), 34 (21.5%) and 33 (20.1%) patients, respectively. The one year and two years follow-up survival periods were confirmed in 39% and 17% of patients respectively. The median survival time in the patients with the neuroendocrine expression as compared to those without the expression was 15.6 vs 10.8 months; one year survival time with the expression compared to those without the expression achieved in 62% vs 27% of the patients, (p < 0.001); a two - year survival time noted in 30% of the patients (p = 0.000). One year follow-up survival time was longer in the patients with neuron specific enolase and chromogranin A expression lung cancer (p < 0.001). Synapthophysin expression was not statisticaly significant for survival (p > 0.05). Conclusion. The results of this study suggest that almost the third of the advanced NSCLC has neuroendocrine differentiation. The median survival time of the treated patients is longer when the tumor is associated with neuron specific enolase and chromogranin A expression. .

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.

Distinction of pulmonary large cell neuroendocrine carcinoma from small cell lung carcinoma: a morphological, immunohistochemical, and molecular analysis

The distinction between pulmonary large cell neuroendocrine carcinoma and small cell carcinoma is difficult in some cases. Some propose that these carcinomas should be classified as one high-grade neuroendocrine carcinoma. We examined biological features of small cell carcinoma (n=23), large cell neuroendocrine carcinoma (n=17), and classic large cell carcinoma (n=12). The average ratio of nuclear diameter of the tumor cells to that of lymphocytes for small cell carcinoma was smaller than that for large cell neuroendocrine carcinoma (P<0.0001). The frequencies of the expressions of CD56, mASH1, TTF-1, and p16 were higher and that of NeuroD was lower in small cell carcinoma than in large cell neuroendocrine carcinoma. The frequency of loss of heterozygosity at 3p was higher in high-grade neuroendocrine carcinomas than in classic large cell carcinoma (P=0.0002). Allelic losses at D5S422 (5q33) were more frequent in small cell carcinoma than in large cell neuroendocrine carcinoma (P=0.0091). Mean fractional regional loss indices of the tumors were 0.38, 0.65, and 0.72 for patients with classic large cell carcinoma, large cell neuroendocrine carcinoma, and small cell carcinoma, respectively (P=0.0003). Five-year overall survivals of patients with classic large cell carcinoma, large cell neuroendocrine carcinoma and small cell carcinoma in stage I were 67, 73, 60%, respectively. Patients with NeuroD expression had better survivals, and those with p63 expression had poorer survivals in large cell neuroendocrine carcinoma. Patients with TTF-1 expression had poorer survivals in small cell carcinoma. Our data suggest that large cell neuroendocrine carcinoma and small cell carcinoma are different morphologically, phenotypically, and genetically, although there are some overlapping features. Although further studies are needed to analyze the biological behavior of high-grade neuroendocrine carcinomas including sensitivity to chemotherapy, the pathological distinction of large cell neuroendocrine carcinoma from small cell carcinoma may be necessary to treat the patients with neuroendocrine tumors.

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.

The Dispersed Neuroendocrine System, Its Bronchopulmonary Elements, and Neuroendocrine Tumors Presumed to be Derived from Them: Myths, Mistaken Notions, and Misunderstandings

The increasing recognition of the dispersed neuroendocrine system and its importance in human physiology has impacted our understanding of physiology, pathophysiology, and histopathology. It has been the subject of a great deal of controversy and debate, giving rise to certain misunderstandings. This article attempts to put some of these issues in perspective, especially as they relate to the bronchopulmonary tree.

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.

Tumeurs neuroendocrines thoraciques

Neuroendocrine pulmonary and thymic tumors constitute a distinct category of tumors collectively disclosing morphologic and biologic neuroendocrine features. They are classified in 4 histopathological types and 3 malignancy grades. The typical carcinoids are of low grade, the atypical carcinoids of intermediate grade and the large cell neuroendocrine carcinoma with the small cell carcinoma are high grade neuroendocrine tumors. Their distinction relies on objective morphologic and phenotypic criteria of strong clinical significance and predictive prognostic value.

Large cell carcinoma with calcitonin and vasoactive intestinal polypeptide-associated Verner-Morrison syndrome

Verner-Morrison syndrome, characterized by diarrhea, hypokalemia, and hypochlorhydria, is caused most commonly by vasoactive intestinal polypeptide-secreting islet cell tumors of the pancreas. Verner-Morrison syndrome has not been described as a paraneoplastic syndrome in non-small cell lung cancer. We describe a 38-year-old man with metastatic non-small cell lung cancer of large cell carcinoma with neuroendocrine differentiation who presented with bone metastasis and intractable secretory diarrhea that was unresponsive to pharmacological treatment, including octreotide. Laboratory evaluation indicated elevated serum calcitonin and vasoactive intestinal polypeptide levels. Chemotherapy resulted in a transient response in the patient's diarrhea and neuroendocrine markers. The patient did not respond to further therapy and died 5 months after onset of back pain. To our knowledge, this is the first published case of large cell carcinoma with neuroendocrine differentiation associated with treatment-responsive paraneoplastic Verner-Morrison syndrome.

Pulmonary large cell neuroendocrine carcinoma demonstrates high proliferative activity

BACKGROUND

In 1999, the World Health Organization classified large cell neuroendocrine carcinoma as a variant of large cell carcinoma and this has been categorized as lying between atypical carcinoid and small cell lung carcinoma in terms of clinical aggressiveness.

METHODS

We analyzed the proliferative activity of stage 1 large cell neuroendocrine carcinoma derived from patients with primary lung cancer who underwent surgical resection and compared the results with stage 1 classic large cell carcinoma cases. The mitotic rate was counted in ten high-power fields of light microscope. Immunohistochemical staining using anti-Ki-67 antibody was performed. The Ki-67 labeling index, expressed as a percentage of positive cells, was determined by light microscopy with random counting of at least 1000 tumor nuclei. The expression of P53 and Bcl-2 was examined and compared.

RESULTS

The mitotic rate of large cell neuroendocrine carcinoma cases was significantly higher than that of classic large cell carcinoma cases. The Ki-67 labeling index of stage 1 large cell neuroendocrine carcinoma cases was significantly higher than that of stage 1 classic large cell carcinoma cases. Immunohistochemical expression of P53 in large cell neuroendocrine carcinoma and classic large cell carcinoma was comparable. However, large cell neuroendocrine carcinoma exhibited a significantly higher expression of Bcl-2 than classic large cell carcinoma. The disease specific disease-free survival for patients with stage 1 large cell neuroendocrine carcinoma was significantly lower than that for patients with stage 1 classic large cell carcinoma.

CONCLUSIONS

Large cell neuroendocrine carcinoma appears to be more clinically aggressive than classic large cell carcinoma with these findings indicating that large cell neuroendocrine carcinoma has a higher level of proliferative activity than classic large cell carcinoma.

Neuroendocrine and biologic features of primary tumors and tissue in pulmonary large cell carcinomas

BACKGROUND

Because biological behavior in lung tumors with neuroendocrine differentiation is highly dependent on cell death (apoptosis) and angiogenesis, p21(waf1/cip1) and microvessel density have been targeted as potentially useful tumor markers. We sought to validate the importance of p21(waf1/cip1) and microvessel density and study their interrelationship, analyzing clinical factors, subclassifications, and tumor and stromal markers.

METHODS

We examined p21(waf1/cip1) and other markers in tissue from 61 patients with surgically excised large cell carcinomas. The amount of tumor staining for p21(waf1/cip1) and microvessel density was evaluated by immunohistochemistry and morphometry. The study outcome was survival time until death from recurrent lung cancer.

RESULTS

Multivariate Cox model analysis demonstrated that after surgical excision, histologic subtypes were significantly related to survival time (p = 0.02), but quantitative staining of the tumor for p21(waf1/cip1) and microvessel density added prognostic information and these variables were more strongly prognostic than histologic subtype (p = 0.00). Cut points at the median staining of 3.5% and 3.0% for p21(waf1/cip1) and microvessel density, respectively, divided patients into two groups with distinctive survival times. Patients with p21(waf1/cip1) staining of more than 3.5% and microvessel density staining of more than 3.0% had a median survival time of 14 months.

CONCLUSIONS

Tumor staining for p21(waf1/cip1) and microvessel density in resected large cell carcinomas and certain other types of lung tumors was strongly related to survival. Patients with more than 3.0% staining in their tumors were at high risk of death from lung cancer and may be an appropriate target for prospective studies of adjuvant chemotherapy after surgical resection.

Outcome of patients with pulmonary carcinoid tumors receiving chemotherapy or chemoradiotherapy

STUDY OBJECTIVES

To determine the outcome of patients with pulmonary typical and atypical carcinoid tumors treated with chemotherapy with or without radiotherapy.

METHODS

Patients with pulmonary neuroendocrine tumors treated at our institution from 1990 to 2001 were identified. The medical records of patients with diagnoses of typical or atypical pulmonary carcinoids were reviewed for the presence of evaluable disease, treatment with chemotherapy with or without radiotherapy, response to these treatments, survival and cause of death.

RESULTS

Eighteen patients with typical (n = 8) or atypical (n = 10) pulmonary carcinoid tumors who were treated with chemotherapy with or without radiotherapy were identified. Of these, four received chemotherapy plus chest radiotherapy. Three of these had stable disease and one had a partial response. One of the patients with stable disease to chemoradiotherapy subsequently received chemotherapy alone, to which he had a complete response. Fourteen additional patients were treated with 18 chemotherapy regimens. There were two partial responses, eight stable disease, seven progressive disease and one allergic reaction precluding further treatment. The overall response rate to any chemotherapy was 3/15 (20%, 95% CI 0.07-0.45), and the best overall response rate to chemotherapy with or without chest radiotherapy was 4/18 (22%, 95% CI 0.09-0.45). Median overall survival was 20 months (95% CI 0-51 months).

CONCLUSIONS

Patients with typical and atypical pulmonary carcinoid tumors can respond to chemotherapy with or without chest radiotherapy, though with response rates that appear less than those of small cell lung cancers. Further characterization of pulmonary carcinoid tumors and study of treatment alternatives for unresectable disease is warranted.

Large cell neuroendocrine carcinoma of the lung: an aggressive disease potentially treatable with surgery

BACKGROUND

Assessment of clinical and pathologic features of large cell neuroendocrine carcinoma to confirm its specificity in the setting of high grade neuroendocrine pulmonary tumors.

METHODS

From 1989 to 2001, 123 patients with a neuroendocrine carcinoma were surgically treated in a curative intent at a single institution. According to the 1999 World Health Organization classification, 20 patients were reviewed as having a large cell neuroendocrine carcinoma. Clinical data as well as detailed pathologic analysis and survival were collected.

RESULTS

There were 18 men and 2 women. The median age was 62 years. Four patients had a preoperative diagnosis of large cell neuroendocrine carcinoma. The resections consisted of 14 lobectomies and 6 pneumonectomies. There was no operative death. Complications occurred in 7 patients (35%). Four patients had a stage I of the disease, 4 had stage II, 9 had stage III, and 3 had stage IV. At follow-up (median, 46 months), 13 patients died from general recurrence and 7 patients were still alive. Median time to progression was 9 months (range, 1 to 54 months). The 5-year survival rate was 36% (median, 49 months) and it seemed to be negatively influenced by the disease stage (54% for stage I-II vs 25% for stage III-IV; p = 0.07), the presence of metastatic lymph node (45% for N0/N1 vs 17% for N2; p = 0.12), or vessel invasion (66 vs 25%; p = 0.18).

CONCLUSIONS

Large cell neuroendocrine carcinoma predominantly occurred in men. An accurate tissue diagnosis was rarely obtained preoperatively. Although overall survival after resection was substantial, large cell neuroendocrine carcinoma frequently showed pathologic features of occult metastatic disease, such as lymph node or vessel invasion, or both.

The prognostic role of c-kit protein expression in resected large cell neuroendocrine carcinoma of the lung

BACKGROUND

Large cell neuroendocrine carcinoma (LCNEC) is a high-grade neuroendocrine tumor of the lung that shares some clinicopathologic and molecular features with small cell lung carcinoma (SCLC). Optimal treatment has not yet been standardized and significant prognostic factors are lacking. Because c-kit protein overexpression has been recently reported as a negative prognostic factor in SCLC we investigated its expression and prognostic value in a series of LCNEC.

METHODS

Resected LCNEC fulfilling the morphologic criteria of the 1999 World Health Organization classification of lung tumors and showing neuroendocrine differentiation by appropriate immunohistochemical markers were retrospectively reviewed. Immunostaining for c-kit protein expression was performed using the polyclonal antibody CD117. Clinical and pathologic characteristic were reported and analyzed and a survival study was performed.

RESULTS

Thirty-three patients underwent radical resection. Thirty-one were male (94%) and 32 were smokers (97%). Ten (30.3%), 11 (33.3%), 5 (15.2%), and 7 (21.2%) were at stage IA, IB, IIB, and IIIA respectively. Overall 1-, 3-, and 5-year survival rates were respectively 79%, 58%, and 51%. Survival analysis showed no differences for any of the clinicopathological features except for CD117 immunostaining: 1-year and 3-year survival rates were respectively 91% and 82% for CD117-negative LCNEC, and 72% and 44% for CD117-positive ones (p = 0.046). Positivity of CD117 was significantly related to recurrence rate: 60% versus 23% for CD117 positive and negative LCNEC respectively (p = 0.037).

CONCLUSIONS

Radical resection of large cell neuroendocrine carcinoma achieves poor outcomes. The c-kit protein is frequently expressed in this neoplasia and its expression represents a negative prognostic factor. This immunohistochemical marker may represent the basic rationale to select LCNEC for novel targeted therapy.

Establishment and characterization of a human large cell lung cancer cell line with neuroendocrine differentiation

Characterization of a human lung cancer cell line is reported. This cell line was established from a patient referred to Nemazi Hospital of Shiraz University of Medical Sciences with a diagnosis of poorly differentiated carcinoma. Sterile sample from peritoneal effusion was taken and immediately cultured in RPMI-1640 medium containing 20% FBS, at 37 degrees C with 5% CO2. This cell line has been in continuous culture for more than one year and has been named as Mehr-80. Several features of the cell line were investigated, including growth characteristics, electron microscopic features, cloning efficiency in soft agar, expression of various antigenic markers, chromosomal and DNA analysis. On the basis of morphological and immunohistochemical analysis of Mehr-80, it is possible to conclude that this cell line is characterized by features similar to those reported for large cell carcinoma with neuroendocrine differentiation (LCCND). This cell line will be a valuable in vitro tool for further studies on lung cancers.

Prognostic implications of neuroendocrine differentiation and hormone production in patients with Stage I nonsmall cell lung carcinoma

BACKGROUND

Approximately 10-20% of nonsmall cell lung carcinomas (NSCLC) show neuroendocrine (NE) differentiation, as evaluated by panendocrine markers or ultrastructural evidence of dense-core secretory granules. However, little is known regarding the prevalence and clinical implications of NE differentiation in patients with Stage I NSCLC.

METHODS

The authors analyzed 220 consecutive patients with Stage I NSCLC (pT1-T2N0M0) among 2100 patients with primary lung carcinoma who underwent surgical treatment between 1987 and 1993. Using light microscopy and immunohistochemical staining for synaptophysin, chromogranin A, and respiratory tract-related hormones, 28 NSCLC specimens with NE differentiation (NSCLC-ND) and 11 large cell neuroendocrine carcinoma (LCNEC) specimens were identified.

RESULTS

The 28 NSCLC-ND specimens included 15 adenocarcinomas and 13 squamous cell carcinomas. Neoplastic cells with NE features never exceeded 20% in NSCLC-ND specimens, whereas neoplastic cells amounted to 20-90% in LCNEC specimens. NSCLC-ND specimens with > 5% NE-differentiated tumor cells showed increased Ki-67 labeling index (P = 0.007) and invasive phenotype, as evaluated by fascin immunoreactivity (P = 0.021). Patients with adenocarcinoma, but not with squamous cell carcinoma, who had > 5% NE-differentiated cells had a worse clinical course compared with patients who had ordinary NSCLC, with reduced overall survival (P = 0.017) and disease free survival (P = 0.049). In multivariate analysis, NE differentiation > 5% neoplastic cells in patients with adenocarcinoma independently predicted a poorer prognosis (hazard ratio, 2.61; 95% confidence interval, 0.99-6.85). Hormone production was restricted to chromogranin positive NSCLC-ND but did not affect prognosis.

CONCLUSIONS

Stage I adenocarcinomas with >or= 5% NE tumor cells are clinically aggressive tumors, similar to LCNEC. Hormone production identifies a more fully developed neuroendocrine phenotype but is not relevant to prognosis. The identification of NE-differentiated cells in patients with NSCLC may have clinical relevance.