Large-Cell Neuroendocrine Carcinoma of the Lung

Clinical significance of ALDH1A1 expression and its association with E-cadherin and N-cadherin in resected large cell neuroendocrine carcinoma

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It is the first study on the effect of ALDH1A1 on the prognosis of LCNEC. And we found ALDH1A1 acts as a favorable independent prognostic factor in LCNEC.

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We investigated the relationship between ALDH1A1 and EMT markers (E-cadherin/ N-cadherin) and found that ALDH1A1 is associated with epithelial phenotype marker E-cadherin in LCNEC.

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

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

Background

The roles of cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT) in solid tumors are well established. However, the interaction between CSCs and EMT in pulmonary large cell neuroendocrine carcinoma (LCNEC) remains unknown. The aim of this study was to investigate the expression and clinical significance of a CSC marker (ALDH1A1) and its correlation with Epithelial-like phenotype marker (E-cadherin) and Mesenchymal-like phenotype marker (N-cadherin) in LCNEC patients.

Methods

Immunohistochemistry (IHC) for ALDH1A1, E-cadherin and N-cadherin expression was conducted on tissue microarrays made from 79 resected LCNEC patient samples. ALDH1A1 protein expression was evaluated by the IHC score, and its correlations with the expression of E-cadherin, N-cadherin and clinicopathological features were determined based on IHC data. Survival analyses were also performed.

Results

ALDH1A1 was positively expressed in 75.9% (60/79 cases) of LCNEC patients. No significant difference in clinicopathological variables was observed between the ALDH1A1-negative and ALDH1A1-positive groups. However, ALDH1A1 expression was positively correlated with E-cadherin (Spearman's rho = 0.229, p-value = 0.007), which represents the epithelial-like phenotype, but not with N-cadherin. Patients with expression of ALDH1A1 had significantly longer disease-free survival (DFS) and overall survival (OS) than those who were ALDH1A1 negative (median DFS: 52 vs 12 months, p = 0.028; median OS: not reached; p = 0.027). Multivariate analysis showed that ALDH1A1 was an independent favorable prognostic factor for DFS (p = 0.032, HR: 0.438, 95% CI: 0.206–0.932) and OS (p = 0.025, HR: 0.279, 95% CI: 0.091–0.852) in LCNEC patients.

Conclusion

This study suggests that ALDH1A1 can act as a favorable independent prognostic factor for LCNEC, which related to the epithelioid phenotype in EMT, and its internal mechanism needs further study.

Recent Advances in Curcumin Treated Non-Small Cell Lung Cancers: An Impetus of Pleiotropic Traits and Nanocarrier Aided Delive ry

Characterized by the abysmal 18% five year survival chances, non-small cell lung cancers (NSCLCs) claim more than half of their sufferers within the first year of being diagnosed. Advances in biomedical engineering and molecular characterization have reduced the NSCLC diagnosis via timid screening of altered gene expressions and impaired cellular responses. While targeted chemotherapy remains a major option for NSCLCs complications, delayed diagnosis, and concurrent multi-drug resistance remain potent hurdles in regaining normalcy, ultimately resulting in relapse. Curcumin administration presents a benign resolve herein, via simultaneous interception of distinctly expressed pathological markers through its pleiotropic attributes and enhanced tumor cell internalization of chemotherapeutic drugs. Studies on NSCLC cell lines and related xenograft models have revealed a consistent decline in tumor progression owing to enhanced chemotherapeutics cellular internalization via co-delivery with curcumin. This presents an optimum readiness for screening the corresponding effectiveness in clinical subjects. Curcumin is delivered to NSCLC cells either (i) alone, (ii) in stoichiometrically optimal combination with chemotherapeutic drugs, (iii) through nanocarriers, and (iv) nanocarrier co-delivered curcumin and chemotherapeutic drugs. Nanocarriers protect the encapsulated drug from accidental and non-specific spillage. A unanimous trait of all nanocarriers is their moderate drug-interactions, whereby native structural expressions are not tampered. With such insights, this article focuses on the implicit NSCLC curative mechanisms viz-a-viz, free curcumin, nanocarrier delivered curcumin, curcumin + chemotherapeutic drug and nanocarrier assisted curcumin + chemotherapeutic drug delivery.

Prevalence of TP-53/Rb-1 Co-Mutation in Large Cell Neuroendocrine Carcinoma

Introduction

Large cell neuroendocrine carcinoma (LCNEC) is a rare and highly aggressive high-grade neuroendocrine neoplasm, which can arise from anywhere in the body. Due to its rarity there is a lacuna in our understanding of LCNEC's molecular biology. In 2016, Rekhtman and colleagues presented one of the largest molecular sequencing series of pulmonary LCNEC. They differentiated genomic profiles of LCNEC into two major subsets: small cell lung cancer (SCLC)-like, characterized by TP53 + RB1 co-mutation/loss, and non-small cell lung cancer (NSCLC)-like, characterized by the lack of co-altered TP53 + RB1. This finding is of significance because at present LCNEC patients are often treated like SCLC. However, the universal genomic SCLC biomarker of TP53 and RB1 co-mutation was only found in 40% of their cohort. Since then various other scientists have looked into molecular profiling of LCNEC with markedly discordant results. The objective of this study was to conduct a systematic review of publicly available next generation sequencing (NGS) data to evaluate the prevalence of TP53 + RB1 co-mutation in LCNEC.

Method

We conducted a literature search using PubMed. Seven studies including 302 patients with pulmonary LCNEC and four studies including 20 patients with extra-pulmonary LCNEC underwent final analysis.

Results

The prevalence of TP53 + RB1 co-mutation was 36% (109/302) among pulmonary LCNEC patients and 35% (7/20) among the extra-thoracic LCNEC cohort. This finding is in stark contrast to >90% TP53 + RB1 co-mutation in SCLC.

Conclusion

It is now well established that LCNEC is molecularly distinct from SCLC. LCNEC seems to have two molecularly defined sub-cohort based on TP53 + RB1 co-mutation status. Future studies should look into prognostic and predictive implication of TP53 + RB1 co-mutation status in LCNEC. Prospective studies should be designed to characterize molecular subtypes and direct treatment accordingly. We are currently conducting a prospective pilot clinical trial wherein LCNEC patients are treated based on TP53 + RB1 co-mutation status. The study is currently enrolling. "Next Generation Sequencing-Based Stratification of Front Line Treatment of Neuroendocrine Carcinoma (PRECISION-NEC).

Systematic Review

ClinicalTrials.gov, identifier NCT04452292.

Outcomes of Patients with Clinical Stage I-IIIA Large-Cell Neuroendocrine Lung Cancer Treated with Resection

Large-cell neuroendocrine carcinoma (LCNEC) is a rare malignancy with poor prognosis. The rationale of the study was to determine the survival of LCNEC patients in I–IIIA clinical stages who underwent resection. A total of 53 LCNEC (89%) and combined LCNEC (11%) patients in stages I–IIIA who underwent surgery with radical intent between 2002–2018 were included in the current study. Overall survival (OS) and time to recurrence (TTR) were estimated. Uni- and multivariable analyses were conducted using Cox-regression model. Patients were treated with surgery alone (51%), surgery with radiochemotherapy (4%), with radiotherapy (2%), with adjuvant chemotherapy (41%), or with neoadjuvant chemotherapy (2%). The median (95% Confidence Interval (CI)) OS and TTR was 52 months (20.1–102.1 months) and 20 months (7.0–75.6 months), respectively. Patients treated in clinical stage I showed better OS than patients in stages II–IIIA (p = 0.008). Patients with R0 resection margin (negative margin, no tumor at the margin) and without lymph node metastasis had significantly better TTR. In the multivariate analysis, age was an independent factor influencing OS. Recurrence within 1 year was noted in more than half cases of LCNEC. R0 resection margin and N0 status (no lymph node metastasis) were factors improving TTR. Age >64 years was observed as a main independent factor influencing OS.

Outcomes for Surgery in Large Cell Lung Neuroendocrine Cancer

INTRODUCTION

There are limited small, single-institution observational studies examining the role of surgery in large cell neuroendocrine cancer (LCNEC). We investigated the outcomes of surgery for stage I to IIIA LCNEC by using the National Cancer Database.

METHODS

Patients with stage I to IIIA LCNEC were identified in the National Cancer Database (2004-2015) and grouped by treatment: definitive chemoradiation versus surgery. Overall survival, by stage, was the primary outcome. Outcomes of surgical patients were also compared with those of patients with SCLC or other non-small cell histotypes.

RESULTS

A total of 6092 patients met the criteria: 96%, 94%, 75%, and 62% of patients received an operation for stage I, II, IIIA, and cN2 disease, respectively. Complete resection was achieved in at least 85% of patients. The 5-year survival rates for patients undergoing an operation for stage I and II LCNEC were 50% and 45%, respectively. Surgical patients with stage IIIA and N2 disease had 36% and 32% 5-year survival rates, respectively. When compared with stereotactic body radiation in stage I disease and chemoradiation in patients with stage II to IIIA disease, surgery was associated with a survival benefit. Patients with LCNEC who underwent an operation generally experienced worse survival by stage than did those with adenocarcinoma but experienced improved survival compared with patients with SCLC. Perioperative chemotherapy was associated with improved survival for pathologic stage II to IIIA disease.

CONCLUSIONS

Surgery is associated with reasonable outcomes for stage I to IIA LCNEC, although survival is generally worse than for adenocarcinoma. Surgery should be offered to medically fit patients with both early and locally advanced LCNEC, with guideline-concordant induction or adjuvant therapy.

Klotho expression and nodal involvement as predictive factors for large cell lung carcinoma

INTRODUCTION

Klotho has been recently described as a carcinogenesis suppressor. Large cell neuroendocrine lung carcinoma (LCNEC) is a rare, highly malignant neoplasm. In the light of increasing incidence of neuroendocrine tumours, biomarkers predicting survival are needed. We consider that Klotho might be one.

MATERIAL AND METHODS

We analysed records of all patients diagnosed with LCNEC, atypical carcinoid and typical carcinoid operated on in our institution between 2007 and 2015. Initially, we found 134 cases. Forty-six specimens were unattainable and thus excluded from research. All patients diagnosed with LCNEC according to the WHO classification were included in the study. Immunohistochemical staining for Klotho was performed. We retrospectively reviewed patient charts and analysed multiple variables.

RESULTS

Positive staining for Klotho was present in 36 tissue specimens, while 12 patients were Klotho-negative. Survival length was significantly higher in Klotho-positive cases (p = 0.024), while advanced nodal status (N1 and N2) represented a marker of poor outcome (p = 0.011). In multivariate analysis, both Klotho presence (p = 0.015; HR = 0.37; 95% CI: 0.17-0.86) and nodal involvement (p = 0.007; HR = 3.04; 95% CI: 1.37-6.82) were independent prognostic factors. Tumour vessel invasion and visceral pleura infiltration were not associated with worse treatment results. Klotho presence predicted a favourable prognosis in these groups (p = 0.018; p = 0.007).

CONCLUSIONS

Our results suggest that Klotho might be a positive factor for predicting survival in LCNEC and nodal involvement a negative one. Thus, these two markers may assist in the selection of subjects with unfavourable prognosis and to personalise therapy regimens.

Small or Non-Small Cell Lung Cancer Based Therapy for Treatment of Large Cell Neuroendocrine Cancer of The Lung? University of Cincinnati Experience

Large cell neuroendocrine cancer (LCNEC) of the lung exhibits morphological and immunohistochemical characteristics of both neuroendocrine and large cell carcinomas. No defined optimal therapy has been described for this subset of patients and the question of whether these patients should be treated with non-small cell lung cancer (NSCLC) treatment protocols, according to the National Comprehensive Cancer Network (NCCN) guidelines, or with small cell lung cancer (SCLC) due to histological and clinical similarities is still uncertain. We conducted a retrospective review of patients identified with diagnosis of LCNEC of the lung at the University of Cincinnati Cancer Center from the year 2002 to 2012 to determine which treatment approach resulted in improved outcomes in this rare category of disease. Patients who received chemotherapy whether NSCLC (group A) or SCLC (group B) protocols did not show significant changes in OS (P=0.911). Meanwhile, patients who underwent surgery (group C) had better OS compared to groups A and B (P= 0.027 and 0.024, respectively). This analysis reveals that outcomes for SCLC or NSCLC treatment strategies in LCNEC patients did not result in survival advantages and future research should be addressing it as a separate entity.

Treatment outcomes and incidence of brain metastases in pulmonary large cell neuroendocrine carcinoma

INTRODUCTION

Large cell neuroendocrine carcinoma (LCNEC) is a rare type of high-grade pulmonary neuroendocrine tumor. The study objective is to investigate its survival outcomes, incidence of brain metastases, and patterns of recurrence.

METHODS

This is a single center study of patients with pathologic diagnosis of pulmonary LCNEC. Patient data were collected retrospectively and analyzed, including survival, incidence of brain metastases, and patterns of recurrence.

RESULTS

Of 87 patients (stages I: 24, II: 14, III: 23, IV: 26), 52 were managed curatively and 35 palliatively. The median follow-up time was 17.3 months (range 0.6-89.5) for those treated with curative intent and 7.0 months (range 0.1-28.6) for those treated palliatively. The 2- and 5-year overall survival (OS) rates are 48.4% and 25.5% for the curative group, with a median OS of 13.5 months. In the palliative group, the OS are 30.8% at 1 year and 6.8% at 2 years, with a median OS of 7.0 months. Thirty-eight of 52 (73%) patients treated with curative intent had disease relapse, with the common sites being regional lymph nodes (20), brain (18), bones (11), and liver (9). The incidence of brain recurrence among those managed curatively are 21.4% and 41.3%, respectively at 1 and 2 years. Of 18 patients experiencing brain metastases, 14 developed them as part of a first relapse.

CONCLUSIONS

LCNEC's survival outcomes are poor. The incidence of brain metastases is higher than what is observed for other types of nonsmall cell lung cancers. Prophylactic cranial irradiation should be investigated as a means of improving outcomes.

The role of surgery in high grade neuroendocrine tumours of the lung

High grade lung neuroendocrine tumours are a heterogeneous subtype of pulmonary cancers including small cell lung cancer (SCLC) and large-cell neuroendocrine carcinoma (LCNEC). LCNEC represents approximately 2-3% of lung cancers, whereas SCLC represents 15-20% of lung cancers. Patients with SCLC and LCNEC have a poor prognosis compared with patients with non-small cell lung cancer (NSCLC). LCNEC is treated with primary surgical resection in stages I-II, which is similar to other NSCLCs. Neo-adjuvant treatment in stage III is similar to NSCLC but has not been well studied. LCNEC tumours have an unfavourable prognosis in higher stages but a more favourable prognosis in earlier stages. Surgery plays a minor role in treatment of SCLC because tumours are often locally advanced or have metastasized at the time of presentation and treatment relies on chemo- or chemoradiotherapy. However, patients with limited cancer may demonstrate better disease control upon surgical treatment. The resection rate of limited disease (LD) SCLC is low (1-6%), but 5-year survival rates of 31-42% after surgical resection are encouraging and are significantly higher than the survival rates of comparable patients that did not have surgery. Curing SCLC in stage I is reported in up to 66% of cases. Local treatment with either resection or radiotherapy alone is followed by high rates of locoregional and distant recurrences, so preoperative or adjuvant treatment is recommended. Here, we summarise the similarities and differences of SCLC and LCNEC and highlight the role of surgery in the treatment of SCLC and LCNEC and its effect on local recurrence prevention.

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.

[A Case of Oropharyngeal Large Cell Neuroendocrine Carcinoma]

The large cell neuroendocrine carcinoma (LCNEC) of the lung was first reported in detail by Travis et al. in 1991. Extrapulmonary LCNEC rarely occurs, and only 22 cases have been reported in the head and neck mucosal regions. Today LCNEC of the larynx is contained in the moderately differentiated/Grade 2 category. However some authors advocate that LCNEC of the larynx should be separated from this category because of the difference in the clinical manifestations and pathological features. Standard treatment for head and neck mucosal LCNEC (M-LCNEC) has not been confirmed. However we suggested the efficacy of postoperative chemotherapy for M-LCNEC. This report describes a case of an LCNEC of the oropharynx. The patient was a 64-year-old man. We treated him with surgery and chemoradiotherapy. He has been disease-free for 36 months after adjuvant-chemotherapy.

Non-small-cell lung carcinoma: role of the Notch signaling pathway

Notch signaling plays a pivotal role during embryogenesis. It regulates three fundamental processes: lateral inhibition, boundary formation, and lineage specification. During post-natal life, Notch receptors and ligands control critical cell fate decisions both in compartments that are undergoing differentiation and in pluripotent progenitor cells. First recognized as a potent oncogene in certain lymphoblastic leukemias and mesothelium-derived tissue, the role of Notch signaling in epithelial, solid tumors has been far more controversial. The overall consequence of Notch signaling and which form of the Notch receptor drives malignancy in humans is deeply debated. Most likely, this is due to the high degree of context-dependent effects of Notch signaling. More recently, it has been discovered that Notch (especially Notch-1) can exert different, even opposite effects in the same tissue under differing microenvironmental conditions. Further complicating the understanding of Notch receptors is the recently discovered role for non-canonical Notch signaling. Additionally, the most frequent Notch signaling antagonists used in biological systems have been inhibitors of the transmembrane protease complex γ-secretase, which itself processes a plethora of class one transmembrane proteins and thus cannot be considered a Notch-specific upstream regulator. Here we review the available empirical evidence gathered in recent years concerning Notch receptors and ligands in non-small-cell lung carcinoma (NSCLC). Although an overview of the field reveals seemingly contradicting results, we propose that Notch signaling can be exploited as a therapeutic target in NSCLC and represents a promising complement to the current arsenal utilized to combat this malignancy, particularly in targeting NSCLC tissues under specific environmental conditions, such as hypoxia.

Large cell neuroendocrine carcinoma: topic review and a unique case of metastasis to the mandible

There are few reports of large cell neuroendocrine carcinoma (LCNEC) metastasis to the head and neck region, and no cases reporting LCNEC from lung metastasizing to the mandible. LCNEC is not well reported in the literature due to recent changes in the criteria for diagnosis, revised in 2004 by the world health organization, due to its propensity for rapid growth and low 5 year prognosis. We present a 61 year old female diagnosed with LCNEC of the lung in October, 2007 treated with radiation and chemotherapy. Our patient had a PET scan performed in March, 2009 revealing no sign of metastasis. In July, 2009 she was seen for suspected sialadenitis by another department and referred to our oral and maxillofacial surgery clinic. Her signs and symptoms were consistent with metastatic disease to the mandible confirmed by histologic and immunohistochemical examination which revealed an invasive poorly differentiated non-small cell carcinoma. Palliative care was offered. Our patient died 2 years after initial diagnosis of lung cancer and 3 months after initial finding of metastatic disease. The rapid growth and spread of this cancer was surprising and knowledge of this cancer should be included in a differential diagnosis of expanding mandibular jaw lesions.

Subpopulations of uPAR+ contribute to vasculogenic mimicry and metastasis in large cell lung cancer

The urokinase plasminogen activator receptor (uPAR) is closely associated with poor prognosis in various aggressive cancers including large-cell lung cancer (LCLC). Vasculogenic mimicry (VM) refers to the unique capability of aggressive tumor cells to mimic the pattern of embryonic vasculogenic networks involving the blood supply in early tumor formation. We demonstrate the statistically positive correlation of uPAR expression with VM formation, metastasis, and poor prognosis of LCLC patients. uPAR(+) cells sorted from the LCLC H460 cell line show higher invasion, migration capacity, and tube structure formation capability on Matrigel compared with uPAR(-) cells. uPAR(+) tumor cells highly expressed vimentin and VE-cadherin; the epithelial marker E-cadherin was low expressed. Higher EMT-regulated protein twist and snail expressions were also observed in these cells. uPAR(+) cells injected subcutaneously into nude mice markedly increased tumor growth, induced VM formation and liver metastasis; by contrast, uPAR(-) cells did not. The data suggest that uPAR expression may predict VM formation, tumor metastasis and poorer prognosis of LCLC patients. The uPAR gene may be used as a novel therapeutic target for inhibiting angiogenesis and metastasis in LCLC.

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.

Large-cell neuroendocrine carcinoma (LCNEC) without pulmonary symptoms diagnosed in a cutaneous metastasis

Patient: Female, 60

Final Diagnosis: Large-cell neuroendocrine carcinoma

Symptoms: Back pain

Medication: —

Clinical Procedure: Vertebroplasty

Specialty: Oncology

Prognostic factors in neuroendocrine tumours of the lung: a single-centre experience

OBJECTIVES

To assess the independent prognostic role of histological subtypes, tumour size and lymph nodal involvement upon survival in lung neuroendocrine tumours (NETs).

METHODS

A retrospective search of the database of the Department of Thoracic Surgery (Turin, Italy) identified 157 patients operated on for a newly diagnosed NET between January 1995 and December 2011. Multivariable Cox models were used to analyse predictors of overall survival and progression-free survival.

RESULTS

According to histology, 71 (45.2%) were typical carcinoids (TCs), 35 (22.3%) atypical carcinoids (ACs), 37 (23.6%) large-cell neuroendocrine carcinomas (LCNCs) and 14 (8.9%) small-cell lung carcinomas (SCLCs). After a median follow-up time of 6.5 years, 60 patients died and 73 had a recurrence or died. The overall 5-, 10- and 15-year survival rates were 64%, 53% and 46%, respectively. Older age, histology (ACs, LCNCs and SCLCs vs TCs) and lymph nodal involvement were confirmed to be independent negative prognostic factors in the multivariable models for overall survival and progression-free survival.

CONCLUSIONS

Tumour histology and lymph nodal involvement are definitively the predominant and relevant factors influencing survival. ACs showed an intermediate prognosis between TCs and poorly differentiated NETs.

Prostatic metastasis of pulmonary large cell neuroendocrine carcinoma

Lung cancer metastases to the prostate are uncommon, and are usually found incidentally during autopsy. This case report describes a 77-year-old man with a large cell neuroendocrine carcinoma (LCNEC) of the lung and metastases from this primary cancer in the prostate. During the follow-up after the chemotherapy performed for pulmonary LCNEC, pelvic computed tomography revealed a prostatic tumor and prostatic needle biopsy was performed. Histologically, the tumor was identified as LCNEC, forming a tissue architecture closely resembling the previously diagnosed lung cancer. The tumor cells were immunohistochemically positive for thyroid transcription factor-1. These findings led to a diagnosis of prostatic metastasis of pulmonary LCNEC.

An Atypical Presentation with Diagnostic Challenge of a Large Cell Neuroendocrine Cancer of Lung: A Case Report and Review of the Literature

Large-cell neuroendocrine carcinomas (LCNECs) are relatively rare and aggressive neoplasms of the lung with very poor prognosis. Even though they are included in the classification of nonsmall cell carcinomas, they have a biological behaviour and physiological response to treatment more like small cell carcinomas of lung. We report an atypical case presentation of LCNEC in a 51-year-old gentleman who presented with diffuse metastases to the thoracic and lumbar spine, brain, and liver, posing a diagnostic challenge. The primary small central lung tumor was in close proximity to major vessels, rendering a biopsy of the primary cancer challenging and nearly impossible. The final diagnosis was established through immunohistochemistry staining and examination of liver biopsy from a metastatic lesion. We also included a review of the current literature pertinent to LCNEC, as well as the important role of tumor markers plus immunohistochemistry profiles in determining the origin of unknown primary tumors in such difficult patient presentations.

Diagnostic issues with cytopathologic interpretation of lung neoplasms displaying high-grade basaloid or neuroendocrine morphology

Basaloid squamous cell carcinoma (BSQCC) and high-grade neuroendocrine carcinomas (HGNEC) including small cell carcinoma (SMCC) and large cell neuroendocrine carcinoma (LCNEC) can be difficult to differentiate on lung cytology. This problem is particularly true in scant specimens where immunoperoxidase stains cannot be adequately performed. Sixty-six cases of BSQCC, LCNEC, and SMCC (22 cases of each) on lung or mediastinal cytology were retrospectively reviewed from the cytopathology archives of two hospitals. Common cytomorphologic characteristics were; hypercellularity, small to intermediate round blue (hyperchromatic) cells, lack of prominent nucleoli, lack of three dimensional architecture, karyorrhexis/necrosis, mitoses, naked nuclei, nuclear crush artifact, and nuclear molding. Distinctive features included: larger cell size with pleomorphism, more cohesive architecture, syncytial aggregation, slightly coarser chromatin texture, rare keratinized malignant cells, and a granular smear background seen more often in BSQCC as opposed to HGNEC. Larger cells with prominent nucleoli and more cytoplasm with focal rosette formation were helpful in distinguishing LCNEC from SMCC and BSQCC. Finally, SMCC displayed uniform small cells with extensive necrosis, and higher mitotic rate. Immunoperoxidase (IPOX) staining using p63, CK5, 6, neuroendocrine markers (chromogranin, synaptophysin and CD56) and TTF-1 were helpful. BSQCC showed p63 expression and was mostly negative for neuroendocrine markers and TTF-1. HGNEC showed immunoreactivity for neuroendocrine markers with variable immunoreactivity for TTF-1. BSQCC, SMCC, and LCNEC share overlapping cytomorphologic features and can be difficult to differentiate on limited cytology specimens. Careful consideration to subtle but definite cytomorphologic clues and attention to selective IPOX stains can lead to a definitive diagnosis.

Analysis of 5-fluorouracil-related enzymes in pulmonary neuroendocrine carcinoma: differences in biological properties compared to epithelial carcinoma

BACKGROUND

Dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT), and thymidylate synthase (TS) levels correlate with sensitivity and resistance to 5-fluorouracil (5-FU). Few data are available on these enzymes in pulmonary neuroendocrine carcinoma, because 5-FU appears to have minimal effect on such carcinomas.

PATIENTS AND METHODS

This study investigated 5-FU-related enzymes in large-cell neuroendocrine carcinoma (LCNEC; n = 31) and small-cell lung carcinoma (SCLC; n = 15), comparing expression levels with epithelial carcinomas including adenocarcinoma (ADC; n = 34) and squamous cell carcinoma (SCC; n = 13) obtained from 93 patients with primary lung tumors. Levels of 5-FU-related enzyme mRNA were analyzed by laser capture microdissection, compared with immunohistochemical findings and correlated with clinicopathologic factors.

RESULTS

LCNEC and SCLC showed significantly higher TS and OPRT mRNA levels than ADC. SCLC exhibited significantly higher TS mRNA levels than LCNEC (P = .002). LCNEC displayed significantly lower DPD mRNA levels than ADC (P < .001), with a similar tendency in SCLC. SCC showed significantly lower DPD (P < .01) and higher OPRT (P < .001) mRNA levels than ADC. When we divide the data by pathology into epithelial carcinoma and neuroendocrine carcinoma, malignant potentials and prognoses correlated with mRNA levels in epithelial carcinoma, but not in neuroendocrine carcinoma. Immunohistochemically, neuroendocrine carcinomas were immunonegative for DPD. A significant correlation was found between enzymatic mRNA and protein expression for DPD (R = .500) and a weak correlation was observed for TS (R = .294).

CONCLUSION

Neuroendocrine carcinomas show characteristic patterns of expression for 5-FU-related enzymes, including low DPD mRNA and protein level and high TS mRNA level compared with adenocarcinomas. These results partially explain why 5-FU-based chemotherapy shows minimal efficacy against SCLC. Conversely, clinicopathological data and survival analysis indicates that 5-FU-related enzymes themselves might not affect the malignant potential of neuroendocrine carcinoma. Expressional differences in 5-FU-related enzymes among pathologies may provide valuable information for tailor-made chemotherapy.

Neuroendocrine tumors of the gallbladder: an evaluation and reassessment of management strategy

BACKGROUND

Gallbladder neuroendocrine tumors (GB-NETs) represent only 0.5% of all NETs, and little is known about their biological behavior. We sought to provide an overview of the current state of knowledge about GB-NETs and provide a recommendation for management.

STUDY

A PubMed search was undertaken using the following criteria: primary gallbladder and carcinoid or NET. We also interrogated the SEER 9, 13 and 17 registries (1973 to 2005) and the Niigata registry (2003) to assess the epidemiology and clinicopathological characteristics. Finally, we compared the clinical presentation, management and prognosis of GB-NETs to that of gallbladder adenocarcinoma.

RESULTS

GB-NETs probably derive from either a multipotent stem cell or neuroendocrine cells in intestinal or gastric metaplasia of the gallbladder epithelium, which occurs consequent upon cholelithiasis/chronic inflammation. Clinically and at surgery, GB-NETs are indistinguishable from gallbladder cancer (GBC) and "carcinoid syndrome" is evident in only ∼1%.The median survival was only 9.8 months among 278 cases of GB-NETs reported in SEER. The 5 year survival rate for tumors classified as carcinoids/neuroendocrine carcinoma or small cell cancer (SCC) was 36.9 and 0%, respectively. Soga divided GB-NETs into typical and variant carcinoids with 5 year survival rates of 60.4% and 21.3% respectively.

CONCLUSIONS

GB-NETs have an aggressive behavior, and once diagnosed, extensive surgical management and careful NET follow up with CT scan is mandatory to facilitate early detection of recurrence. Since more aggressive surgical management for GBC has shown increased survival rates for these tumors, a similar strategy seems reasonable for GB-NETs. However, in high grade metastatic tumors, the primary management is mainly medical.

Downregulation of Fzd6 and Cthrc1 and upregulation of olfactory receptors and protocadherins by dietary beta-carotene in lungs of Bcmo1-/- mice

An ongoing controversy exists on beneficial versus harmful effects of high beta-carotene (BC) intake, especially for the lung. To elucidate potential mechanisms, we studied effects of BC on lung gene expression. We used a beta-carotene 15,15'-monooxygenase 1 (Bcmo1) knockout mouse (Bcmo1(-/-)) model, unable to convert BC to retinoids, and wild-type mice (Bcmo1(+/+)) mice to dissect the effects of intact BC from effects of BC metabolites. As expected, BC supplementation resulted in a higher BC accumulation in lungs of Bcmo1(-/-) mice than in lungs of Bcmo1(+/+) mice. Whole mouse genome transcriptome analysis on lung tissue revealed that more genes were regulated in Bcmo1(-/-) mice than Bcmo1(+/+) mice upon BC supplementation. Frizzled homolog 6 (Fzd6) and collagen triple helix repeat containing 1 (Cthrc1) were significantly downregulated (fold changes -2.99 and -2.60, respectively, false discovery rate < 0.05) by BC in Bcmo1(-/-). Moreover, many olfactory receptors and many members of the protocadherin family were upregulated. Since both olfactory receptors and protocadherins have an important function in sensory nerves and Fzd6 and Cthrc1 are important in stem cell development, we hypothesize that BC might have an effect on the highly innervated pulmonary neuroendocrine cell (PNEC) cluster. PNECs are highly associated with sensory nerves and are important cells in the control of stem cells. A role for BC in the innervated PNEC cluster might be of particular importance in smoke-induced carcinogenesis since PNEC-derived lung cancer is highly associated with tobacco smoke.

Bronchopulmonary neuroendocrine tumors

Bronchopulmonary neuroendocrine tumors (BP-NETs) comprise approximately 20% of all lung cancers and represent a spectrum of tumors arising from neuroendocrine cells of the BP-epithelium. Although they share structural, morphological, immunohistochemical, and ultrastructural features, they are separated into 4 subgroups: typical carcinoid tumor (TC), atypical carcinoid tumor (AC), large-cell neuroendocrine carcinoma (LCNEC), and small-cell lung carcinoma (SCLC), which exhibit considerably different biological characteristics. The clinical presentation includes cough, hemoptysis, and obstructive pneumonia but varies depending on site, size, and growth pattern. Less than 5% of BP-NETs exhibit hormonally related symptoms such as carcinoid syndrome, Cushing, acromegaly, and SIADH. SCLC is the most common BP-NET, while LCNEC is rare, approximately 10% and < or =1%, respectively, of all lung cancers. Both SCLC and LCNEC progress rapidly, are aggressively metastatic, and exhibit a poor prognosis. The incidence of BP-carcinoids (TC and AC) in the US was 1.57 of 100,000 in 2003 (an unexplained and substantial increase over the last 30 years, approximately 6% per year). No curative treatment except for radical surgery (almost never feasible) exists. The slow-growing TC exhibit a fairly good prognosis ( approximately 88%, 5-year survival), whereas AC demonstrate a 5-year survival of approximately 50%, and the highly malignant LCNEC and SCLC5-year survival of 15% to 57% and <5%, respectively. This review provides a broad overview on BP-NETs and focuses on the evolution of the disease, general features, and current diagnostic and therapeutic options.