Expression analysis of genes involved in DNA repair or synthesis in mixed neuroendocrine/nonneuroendocrine carcinomas

An Italian real-world multicenter study of patients with advanced mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) of the gastro-entero-pancreatic system treated with chemotherapy

PURPOSE

The aim of this study is to describe the clinical management of an Italian series of patients with advanced gastro-entero-pancreatic (GEP) MiNENs treated in clinical practice.

METHODS

Clinical records of patients from four Italian referral Centers were retrospectively analyzed to correlate clinical/biological data with clinical outcomes. All the surgical specimens were centrally reviewed.

RESULTS

Clinical data and surgical samples of 51 patients during 1995-2015 were analyzed. Sites of origin were: 32 colorectal, 14 gastro-esophageal, and 5 pancreatobiliary. Twenty-one out of fifty-one (42.2%) developed metachronous distant metastases. Only 5/51 (9.8%) patients received peri-operative therapy, and 23/51 (45.1%) first-line chemotherapy, mostly fluoropyrimidines/oxaliplatin. The NEN component was poorly differentiated in the whole population. Patients with Ki67 index < 55% in the NEC component had a significantly longer median overall survival (OS) (35.3 months; 95% CI 27.1-41.0) than those with Ki67 ≥ 55% (11.9 months; 95% CI 9.1-14.0) P = 0.0005. The median OS was 14 months (95% CI 10.1-19.1) in the whole cohort, with 11.4 months (95% CI 6.2-20.2) in patients who received a first-line therapy.

CONCLUSION

This study confirms that GEP-MiNENs represent a complex disease and that over the past years the clinical management has been predominantly guided by the subjective judgment of the clinicians. Although, in this series, the NEC component appeared mostly responsible for the systemic spread and prognosis on the whole neoplasm, the lack of strong prognostic and predictive factors universally recognized seems to condition their management so far. Future prospective clinical and biomolecular studies could help clinicians to improve clinical management of GEP-MiNENs.

Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) are a heterogeneous group of malignant neoplasms that can settle in the gastroenteropancreatic tract. They are composed of a neuroendocrine (NE) and a non-NE component in at least 30% of each tumour. The non-NE component can include different histological combinations of glandular, squamous, mucinous and sarcomatoid phenotypes, and one or both of the components can be low-or high grade malignant. Recent changes in the nomenclature of these neoplasms might lead to great deal of confusion, and the lack of specific clinical trials is the main reason why their management is difficult. The review aims to clarify the definition of MiNEN and analyze available evidence about their diagnosis and treatment options according to their location and extension through careful analysis of the available data. It would be important to reach a general consensus on their diagnosis in order to construct a classification that remains stable over time and facilitates the design of clinical trials that, due to their low incidence, will require long recruitment periods.

Mixed neuroendocrine–nonneuroendocrine neoplasms of the gastrointestinal system: An update

Mixed neuroendocrine-nonneuroendocrine neoplasms (MiNENs) of the digestive tract are a rare heterogeneous group of tumors that present many challenges in terms of diagnosis and treatment. Over the years, the diagnostic criteria, classification, and clinical behavior of these tumors have been the subjects of ongoing debate, and the various changes in their nomenclature have strengthened the challenges associated with MiNENs. This review is performed to provide an understanding of the key factors involved in the evolution of the designation of these tumors as MiNEN, highlight the current diagnostic criteria, summarize the latest data on pathogenesis and provide information on available treatments. Moreover, this work seeks to increase the awareness about these rare neoplasms by presenting the clinicopathological features and prognostic factors that play important roles in their behavior and discussing their different regions of origin in the gastrointestinal system (GIS). Currently, the MiNEN category also includes tumors in the GIS with a nonneuroendocrine component and epithelial tumors other than adenocarcinoma, depending on the organ of origin. Diagnosis is based on the presence of both morphological components in more than 30% of the tumor. However, this value needs to be reconfirmed with further studies and may be a limiting factor in the diagnosis of MiNEN by biopsy. Furthermore, available clinicopathological data suggest that the inclusion of amphicrine tumors in the definition of MiNEN is not supportive and warrants further investigation. The diagnosis of these tumors is not solely based on immunohistochemical findings. They are not hybrid tumors and both components can act independently; thus, careful grading of each component separately is required. In addition to parameters such as the metastatic state of the tumor at the time of diagnosis and the feasibility of surgical resection, the aggressive potential of both components has paramount importance in the choice of treatment. Regardless of the organ of origin within the GIS, almost MiNENs are tumors with poor prognosis and are frequently encountered in the elderly and men. They are most frequently reported in the colorectum, where data from molecular studies indicate a monoclonal origin; however, further studies are required to provide additional support for this origin.

Mixed neuroendocrine non-neuroendocrine neoplasm of the gallbladder complicated by a pancreaticobiliary maljunction of a non-dilated biliary duct: A case report

RATIONALE

Mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) is a rare tumor. MiNEN of the gallbladder (GB) with pancreaticobiliary maljunction (PMJ) is extremely rare. The origin of MiNEN of the GB remains unknown; the biliary tract normally lacks neuroendocrine cells. MiNEN of the GB has a poor prognosis; because of its rarity, no treatment or management guidelines have been established yet.

PATIENT CONCERNS

A 47-year-old male presenting with right hypochondrial pain and malaise for 3 months was referred to our hospital for further management.

DIAGNOSIS

The neuron-specific enolase level was increased. Contrast-enhanced computed tomography revealed a mass of 70 mm in size with unclear boundaries in the liver. The GB was surrounded by this mass, narrowing the lumen of the GB. Many swollen lymph nodes were observed in the hepatoduodenal ligament. Endoscopic retrograde cholangiopancreatography revealed a PMJ with a non-dilated biliary duct. A percutaneous biopsy was performed on the liver mass, and the pathological findings were neuroendocrine carcinoma (NEC) (small cell type). We diagnosed a NEC of the GB, T3N1M0, stage IIIB (Union for International Cancer Control, 7th edition).

INTERVENTIONS

Because of advanced lymph node metastasis, we considered this tumor difficult to cure solely by surgical intervention. After initial chemotherapy consisting of cisplatin and irinotecan, a marked reduction in both tumor and lymph node sizes enabled conversion surgery. The pathological diagnosis of the resected tumor was MiNEN consisting of NEC and adenocarcinoma. The primary lesion was the adenocarcinoma occupying the luminal side of the GB. As a postsurgical treatment, the patient received additional irradiation therapy to the common hepatic duct and liver stump because of positive surgical margins.

OUTCOMES

At 13 months postoperatively, computed tomography findings revealed the appearance of a hypervascular liver tumor, and laboratory data showed increased serum neuron-specific enolase levels. Chemotherapy was unsuccessful, leading to the death of the patient 36 months from the date of diagnosis.

LESSONS

There are several reports on the development of MiNEN of the GB. In our case, a PMJ-related adenocarcinoma of the GB transdifferentiated into NEC. Further accumulation of cases is necessary to establish a treatment strategy for MiNEN of the GB.

GNEN-1: a spontaneously immortalized cell line from gastric neuroendocrine neoplasia

Mixed neuroendocrine-non-neuroendocrine neoplasms (MINEN) are rare tumors that consist of at least 30% of both neuroendocrine and non-neuroendocrine components. The data concerning the pathogenesis of MINEN suggest a monoclonal origin. We describe a spontaneously immortalized cell line derived from gastric MINEN called GNEN-1. Primary tumor consisted of components of high-grade neuroendocrine carcinoma and adenocarcinoma. The GNEN-1 cell line was initiated from metastatic tumor cells of peritoneal fluid and expresses a purely neuroendocrine phenotype. The GNEN-1 cell line grows as monolayers and has retained the neuroendocrine phenotype with positivity for chromogranin A in immunohistochemistry. Electron microscopy showed cytoplasmic dense core granules and axon hillocks. The karyotype revealed alterations typical of both adenocarcinoma and neuroendocrine carcinoma such as trisomy 7 and 8. GNEN-1 cells were also positive for stanniocalcin-1, a marker of poor prognosis in gastric carcinomas. Expression of several markers related to neuroendocrine tumors was found. There have been only a few studies on the pathogenesis of MINEN and management of the disease due to the rarity of this tumor type. Here we describe for the first time an immortalized cell line derived from mixed gastric NEN. The GNEN-1 line offers a tool for future research on gastric NEN.

Does Mixed Neuroendocrine-Nonneuroendocrine Neoplasm (MiNEN) of the Parathyroid Gland Exist? First Description of a Possible Case

We describe the histological, histochemical, and immunohistochemical features of an unusual neoplasm of the parathyroid gland showing the histologic criteria of a mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN). To the best of our knowledge, this is the first report of such a tumor. A 43-year old male presented with acute and severe abdominal pain due to acute pancreatitis. On physical examination a painless lump in the right neck was detected and laboratory analyses revealed hyperparathyroidism (parathormone: 146 pmol/L, normal range 1.05-6.83) and hypercalcemia (calcium level: 3.02 mg/dL, normal range 2.25-2.5), which fell to 2.55 mg/dL after parathyroidectomy. Histologically, the tumor was a parathyroid carcinoma associated with a mucous secreting adenocarcinoma also confirmed by histochemical (Alcian blue-periodic acid Schiff) and immunohistochemical stainings. The present case expands the spectrum of MiNENs that can be found in endocrine organs.

Mixed neuroendocrine-non-neuroendocrine neoplasms of ascending colon: A case report

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Colon MiNEN, in this case, adenocarcinoma and NET G1 is a rare tumor.

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Preoperative diagnosis of MiNEN is difficult, and detailed observation of histopathology is important.

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Prognosis depends on the more aggressive components of adenocarcinoma or NET.

Introduction

Neuroendocrine tumor (NET) that develops in the right-sided colon is relatively rare. Coexistence of adenocarcinoma and NET is extremely rare, and such cases are called mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN).

Presentation of case

Colonoscopy in an 85-year-old woman for an anemia examination indicated laterally spreading tumor-nongranular (LST-NG) in the transverse colon. Colonoscopy and endoscopic ultrasonography (EUS) showed that the depth of the tumor invasion was deep submucosal. The tumor localization was diagnosed as transverse colon close to the hepatic curvature by enema. Computed tomography (CT) showed no obvious lymph node or distant metastasis. Based on these findings, laparoscopic transverse colectomy with D2 lymphadenectomy was performed. Pathologically, most of the tumor was well-differentiated tubular adenocarcinoma, but some solid follicles of polygonal tumor cells with poor nuclear atypia were observed. Immunostaining was positive for synaptophysin and diagnosed as NET G1. This tumor consisted of adenocarcinoma and neuroendocrine tumor, so we diagnosed it as MiNEN and classified the tumor as fT1N0M0 fStage I (TNM Classification of Malignant Tumors, 8th Edition). Since it was an early stage cancer, postoperative adjuvant therapy was not performed. No recurrence has yet been noted.

Discussion

Although MiNEN is extremely rare, the detailed pathological specimen observation and diagnosis are important because long-term follow-up after surgery is needed, as is the adequate selection of postoperative adjuvant therapy.

Conclusion

It is important to elucidate the mechanisms involved in the coexistence of NET and adenocarcinoma and to apply these findings to future medical care.

Looking into digestive mixed neuroendocrine - nonneuroendocrine neoplasms: subtypes, prognosis, and predictive factors

Mixed neuroendocrine - nonneuroendocrine neoplasms (MiNENs) of the digestive system represent a challenge for both pathologists and clinicians. Their nomenclature has changed several times, and their diagnostic criteria, classification and clinical behaviour have been matter of debate over the years. Although several attempts have been made to elucidate the pathogenesis and biology of MiNENs, some issues remain open. This review will provide: a historical background that helps in understanding the evolution of the concept and nomenclature of mixed neoplasms; a revision of the knowledge on this topic, including molecular aspects, to give the reader a comprehensive and practical overview on this challenging field of pathology; a focus on the diagnostic criteria and on the determination of prognostic and predictive factors; and a description of the different tumour types in the different sites of origin.

Clinical implications of mismatch repair deficiency screening in patients with mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN)

INTRODUCTION

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) are rare tumors, mainly encountered in the gastroenteropancreatic tract. Based on the limited available data, MiNEN is usually a highly aggressive neoplasm combining a high-grade neuroendocrine and a non-neuroendocrine component, associated with a poor prognostic outlook. Deficient DNA mismatch repair (MMR) results in microsatellite instability, which is a useful screening marker for identifying patients with Lynch syndrome and a prognostic factor for chemotherapeutic interventions. Little information on MMR status in MiNEN is available in published studies. Therefore, the purpose of this study was to explore the status and putative role of MMR on MiNEN.

METHODS

We investigated the MMR status in 44 cases and characterized their clinicopathological features and prognoses. Immunohistochemistry was performed for four mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2).

RESULTS

Mean age at diagnosis was 61 years, and 75% of the patients were male. Lymph node metastases were observed in 14 (35.9%) patients. The most common tumor localizations were gastric (28 patients, 63.6%). Lack of immunohistochemical expression of MMR proteins was shown in 38.6% of cases. The common deletion rates of one or more proteins were 29.4% (5/17) for MLH1/PMS2 and 23.5% (4/17) for MLH1. Correlation between clinicopathological parameters showed that MMR deficiency was significantly associated with early TNM stage and better prognoses in patients with MiNEN.

CONCLUSION

MiNENs showed frequent losses of MMR protein expression, which contributes to the knowledge of the pathological and clinical aspects of MiNEN tumors.

Gallbladder Mixed Neuroendocrine-Non-neuroendocrine Neoplasm (MiNEN) Arising in Intracholecystic Papillary Neoplasm: Clinicopathologic and Molecular Analysis of a Case and Review of the Literature

Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) of the gallbladder are generally composed of adenocarcinoma and neuroendocrine carcinoma (NEC). Rare cases associated with intracholecystic papillary neoplasm (ICPN) have been reported. Although recent molecular data suggest that the different components of digestive MiNENs originate from a common precursor stem cell, this aspect has been poorly investigated in gallbladder MiNENs. We describe the clinicopathologic and molecular features of a MiNEN composed of ICPN, adenocarcinoma, and NEC. A 66-year-old woman presented with severe abdominal pain. She underwent radical cholecystectomy and an intracholecystic mass was found. Histologically, it was composed of ICPN associated with adenocarcinoma and large cell neuroendocrine carcinoma (LCNEC). The three components were positive for DNA repair proteins and p53. EMA was positive in the ICPN and adenocarcinoma components, while it was negative in the LCNEC. Heterogeneous expression of Muc5AC, cytokeratin 20, and CDX2 was only observed in the ICPN component. Cytokeratin 7 was diffusely positive in both adenocarcinoma and LCNEC components, while it was heterogeneously expressed in the ICPN. The copy number variation analysis showed overlapping results between the adenocarcinoma and LCNEC components with some minor differences with the ICPN component. The three tumor components showed the same mutation profile including TP53 mutation c.700T > C (p. Tyr234His), without mutations in other 51 genes known to be frequently altered in cancer pathogenesis and growth. This finding may support the hypothesis of a monoclonal origin of the different tumor components. We have also performed a review of the literature on gallbladder MiNENs.

Management of Well-Differentiated High-Grade (G3) Neuroendocrine Tumors

OPINION STATEMENT

In 2017, the World Health Organization (WHO) classification for pancreatic NET was updated to include a new category of well-differentiated high-grade (Ki 67 > 20%) pancreatic tumors (NET G3), distinct from high-grade poorly differentiated neuroendocrine carcinoma (NEC). NET G3 are considered a molecularly, radiologically, and prognostically distinct entity compared to NEC and NET G1/G2. The optimal first-line management in NET G3 and sequencing therapies remains a challenge awaiting future trials taking into consideration the unique characteristics of this category. In this review, we aim to summarize the current evidence in the management of NET G3.

Recent advances in the molecular landscape of lung neuroendocrine tumors

INTRODUCTION

Neuroendocrine tumors of the lung (Lung-NETs) make up a heterogenous family of neoplasms showing neuroendocrine differentiation and encompass carcinoids and neuroendocrine carcinomas. On molecular grounds, they considered two completely distinct and separate tumor groups with no overlap of molecular alterations nor common developmental mechanisms. Areas covered: Two perspectives were evaluated based on an extensive review and rethinking of literature: (1) the current classification as an instrument to obtaining clinical and molecular insights into the context of Lung-NETs; and (2) an alternative and innovative interpretation of these tumors, proposing a tripartite separation into early aggressive primary high-grade neuroendocrine tumors (HGNET), differentiating or secondary HGNET, and indolent NET. Expert opinion: We herein provide an alternative outlook on Lung-NETs, which is a paradigm shift to current pathogenesis models and expands the understanding of these tumors.

Mixed adenoneuroendocrine carcinoma of the colon and rectum

Mixed adenoneuroendocrine carcinoma (MANEC) are rare cancers of the gastrointestinal (GI) and pancreatobiliary tract. They are characterized by the presence of a combination of epithelial and neuroendocrine elements, where each component represents at least 30% of the tumour. Review of literature and consolidation of clinicopathological data. Sixty-one cases of colorectal MANEC have been reported in literature and one seen in this centre. The median age of the patients affected was 61.9 ± 12.4 years (20-94 years). Male to female ratio is 1.0:1.2. Presentations were similar to other colorectal malignancies. 58.0% of colorectal MANECs were found in the right colon, 8.1% cases in the transverse, 16.1% in the left colon, 16.1% in the rectum. These tumours appeared invasiveness 79.1% were T3-T4. Over 90% of cases were presented with metastatic disease. The majority of patient underwent surgical resection of the primary cancer (96.6%). Of these, 10 operations (17.9%) were emergency operations due to obstruction, perforation, or bleeding. Three patients received first line palliative care. In eight cases (13.8%), patients underwent adjuvant chemotherapy. The median overall survival after diagnosis was 10 ± 2.4 months (95% CI: 5.37-14.64 months). MANECs are rare but aggressive colorectal cancers. Surgical resection of localized disease with adjuvant chemotherapy appears to significantly improve survival in small case series. Further understanding through the sharing of experiences is required.

Ki67 proliferative index of the neuroendocrine component drives MANEC prognosis

Mixed adenoneuroendocrine carcinomas (MANECs) are composed of a poorly differentiated neuroendocrine carcinoma (NEC) and a non-neuroendocrine (non-NEC) neoplastic epithelial component, each representing at least 30% of the tumor. At present, prognostic factors for MANECs remain largely unexplored. We investigated the clinical-pathologic features of a large multicenter series of digestive system MANECs. Surgical specimens of 200 MANEC candidates were centrally reviewed; diagnosis was confirmed in 160 cases. While morphology, proliferation (mitotic count (MC), Ki67 index) and immunophenotype (p53, SSTR2a, beta-Catenin, Bcl-2, p16, Rb1, ALDH, mismatch repair proteins and CD117) were investigated separately in both components, genomic (TP53, KRAS, BRAF) alterations were searched for on the entire tumor. Data were correlated with overall survival (OS). MANEC sites were: 92 colorectal, 44 gastroesophageal and 24 pancreatobiliary. Median OS was 13.2 months. After adjustment for primary site, Ki67 index of the NEC component (but not of the non-NEC component) was the most powerful prognostic marker. At multivariable analysis, patients with Ki67 ≥ 55% had an 8-fold risk of death (hazard ratio (HR) 7.83; 95% confidence interval (CI) 4.17-14.7; P < 0.0001) and a median OS of 12.2 months compared to those with Ki67 < 55% (median OS 40.5 months). MC (HR 1.51; 95% CI 1.03-2.20, P = 0.04) was a weaker prognostic index. Colorectal primary site (HR 1.60; 95% CI 1.11-2.32; P = 0.01) was significantly associated with poorer survival. No single immunomarker, in either component, was statistically significant. This retrospective analysis of a large series of digestive system MANECs, showed that the NEC component, particularly its Ki67 index, was the main prognostic driver.

Classification of pulmonary neuroendocrine tumors: new insights

Neuroendocrine tumors of the lung (Lu-NETs) embrace a heterogeneous family of neoplasms classified into four histological variants, namely typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC). Defining criteria on resection specimens include mitotic count in 2 mm2 and the presence or absence of necrosis, alongside a constellation of cytological and histological traits including cell size and shape, nuclear features and overall architecture. Clinically, TC are low-grade malignant tumors, AC intermediate-grade malignant tumors and SCLC/LCNEC high-grade malignant full-blown carcinomas with no significant differences in survival between them. Homologous tumors arise in the thymus that occasionally have some difficulties in differentiating from the lung counterparts when presented with large unresectable or metastatic lesions. Immunohistochemistry (IHC) helps refine NE diagnosis at various anatomical sites, particularly on small-sized tissue material, in which only TC and small cell carcinoma categories can be recognized easily on hematoxylin & eosin stain, while AC and LCNEC can only be suggested on such material. The Ki-67 labeling index effectively separates carcinoids from small cell carcinoma and may prove useful for the clinical management of a metastatic disease to help the therapeutic decision-making process. Although carcinoids and high-grade neuroendocrine carcinomas in the lung and elsewhere make up separate tumor categories on molecular grounds, emerging data supports the concept of secondary high-grade NETs arising in the preexisting carcinoids, whose clinical and biological relevance will have to be placed into the proper context for the optimal management of these patients. In this review, we will discuss the selected, recent literature with a focus on current issues regarding Lu-NET nosology, i.e., classification, derivation and tumor evolution.

Mixed Neuroendocrine-Nonneuroendocrine Neoplasms (MiNENs): Unifying the Concept of a Heterogeneous Group of Neoplasms

The wide application of immunohistochemistry to the study of tumors has led to the recognition that epithelial neoplasms composed of both a neuroendocrine and nonneuroendocrine component are not as rare as traditionally believed. It has been recommended that mixed neuroendocrine-nonneuroendocrine epithelial neoplasms are classified as only those in which either component represents at least 30 % of the lesion but this cutoff has not been universally accepted. Moreover, since their pathogenetic and clinical features are still unclear, mixed neuroendocrine-nonneuroendocrine epithelial neoplasms are not included as a separate clinicopathological entity in most WHO classifications, although they have been observed in virtually all organs. In the WHO classification of digestive tumors, mixed neuroendocrine-nonneuroendocrine neoplasm is considered a specific type and is defined as mixed adenoneuroendocrine carcinoma, a definition that has not been accepted for other organs. In fact, this term does not adequately convey the morphological and biological heterogeneity of digestive mixed neoplasms and has created some misunderstanding among both pathologists and clinicians. In the present study, we have reviewed the literature on mixed neuroendocrine-nonneuroendocrine epithelial neoplasms reported in the pituitary, thyroid, nasal cavity, larynx, lung, digestive system, urinary system, male and female genital organs, and skin to give the reader an overview of the most important clinicopathological features and morphological criteria for diagnosing each entity. We also propose to use the term "mixed neuroendocrine-nonneuroendocrine neoplasm (MiNEN)" to define and to unify the concept of this heterogeneous group of neoplasms, which show different characteristics mainly depending on the type of neuroendocrine and nonneuroendocrine components.