Classification Of Neuroendocrine Tumors Research Articles

Neuroendocrine tumors of the kidneys

The 2004 World Health Organization (WHO) classification of renal cancer includes renal carcinoid and neuroendocrine cancer of the kidneys in the group of primary renal neuroendocrine tumors. The histological features of primary renal carcinoids are similar to those of neuroendocrine tumors found in other anatomical locations. Primary carcinoid tumors of the kidneys are frequently misdiagnosed as other kidney cancers, such as papillary renal cell carcinoma, mesonephric tumors, Wilms tumor (WT) and undifferentiated carcinoma. Immunohistochemical staining results are consistent with the diagnosis of a neuroendocrine tumor with immunoreactivity for synaptophysin, chromogranin, CD56, and neuron-specific enolase (NSE). Positive expression of CD99 can also be seen. There is mainly absence of WT1, cytokeratin 7, cytokeratin 20, thyroid transcription factor (TTF1) and LCA, ruling out most other differential diagnoses. Renal carcinoid tumors are regarded as low-grade neuroendocrine tumors; however, many studies have demonstrated metastatic disease in patients with renal carcinoid tumors. The prognostic value of histological parameters is uncertain. Some studies have correlated poor patient prognosis with increased mitotic activity, presence of necrosis and cytological atypia. Cases with higher mitotic rates of > 2 mitoses/10 high power fields (HPF) developed metastases more frequently; therefore, the WHO classification of neuroendocrine tumors used in other organs is recommended for primary renal carcinoid tumors.

Pathology: Classification and Immunoprofile.

The classification of neuroendocrine neoplasms (NENs) has been evolving steadily over the last decades. Important prognostic factors of NENs are their proliferative activity and presence/absence of necrosis. These factors are reported in NENs of all body sites; however, the terminology as well as the exact rules of classification differ according to the location of the primary tumor. Only in gastroenteropancreatic (GEP) NENs a formal grading is performed. This grading is based on proliferation assessed by the mitotic count and/or Ki-67 proliferation index. In the lung, NEN grading is an intrinsic part of the tumor designation with typical carcinoids corresponding to neuroendocrine tumor (NET) G1 and atypical carcinoids to NET G2; however, the presence or absence of necrotic foci is as important as proliferation for the differentiation between typical and atypical carcinoids. Immunohistochemical markers can be used to demonstrate neuroendocrine differentiation. Synaptophysin and chromogranin A are, to date, the most reliable and most commonly used for this purpose. Beyond this, other markers can be helpful, for example in the situation of a NET metastasis of unknown primary, where a hormonal profile or a panel of transcription factors can give hints to the primary site. Many immunohistochemical markers have been shown to correlate with prognosis but are not used in clinical practice, for example cytokeratin 19 and KIT expression in pancreatic NETs. There is no predictive biomarker in use, with the exception of somatostatin receptor (SSTR) 2 expression for predicting the amenability of a tumor to in vivo SSTR targeting for imaging or therapy.

English

Neuroendocrine tumors (NETs) can arise in various organs of the body and share many common pathologic features. Although there are various classification systems, World Health Organization (WHO) proposed classification of NETs based on differentiation and grading for prognostic and therapeutic implications. Ki-67 index and Mitotic index are the most important criteria for grading of NETs. Many studies have been done concerning prognostic role of Ki-67 index in NETs specific to organ systems, but fewer data are available about patients with NETs of heterogenous origin. The aim of our study was to evaluate the prognostic significance of Ki-67 index and mitotic index in NETs. A total of 50 patients undergoing multidisciplinary management were analyzed prospectively over a period of 4 years, from 2010 to 2014. Among various locations, NETs most commonly involved gastrointestinal tract. The study population was classified into three grades. Grade I (13 patients), Grade II (10 patients) and Grade III (27 patients). There was a significant association between tumor grading and metastasis where tumor grading served the most important predictor of outcome.

Therapeutic biomarkers in lung neuroendocrine neoplasia.

The well-known classification of neuroendocrine neoplasms of the lung into four major subtypes (including typical and atypical carcinoids and small- and large-cell neuroendocrine carcinomas) has a proven prognostic validity but only partially helps to predict the response to specific therapies. Therapeutic biomarkers are incompletely known and include morphological, immunophenotypic, and molecular markers. Morphology alone has no specific predictive role, nor has any immunophenotypic marker been proven to bear predictive implications. Ki67 is a relevant prognostic marker and can indirectly predict response to chemotherapy, when levels are extremely high in high-grade neuroendocrine (NE) carcinomas. The expression of somatostatin receptors, especially of the type 2A, has been shown to predict response to somatostatin analog treatments, paralleling the information derived from octreotide scintigraphy. mTOR pathway is targeted by specific inhibitors, but the exact cellular molecules predicting response are still to be defined. It seems that high levels of phosphorylated forms of mTOR and of its downstream factor S6K are associated to a better response to rapalogs in experimental models. Data from gene expression profiling and mutational analyses are currently emerging, providing a more detailed map of different molecular activation pathways, potentially leading to a more accurate molecular classification of lung NE tumors as well as to the discovery of new therapeutic targets. The combination of mutational profiles with those of upregulated or downregulated genes also by gene gains or losses may ultimately provide a better characterization of NE tumor histological types in terms of response to specific chemotherapy or biotherapy.

Acute appendicitis associated with an appendiceal carcinoid tumor

A 28-year-old man presentedwith acute periumbilical pain for 1 day. The pain had started in the periumbilical region and then shifted to the right lower quadrant with intermittent abdominal cramps. He visited the hospital and was admitted with the suspicion of acute appendicitis. He was afebrile and hemodynamically stable. No rebound tenderness or abdominal guarding was noted during the physical examination. The appendix could not be visualized by ultrasonography. A computed tomographic scan showed an edematous and dilated appendix with fecolith and one nodular lesion over the proximal part of the appendix (Fig. 1A, arrow). The patient underwent appendectomy, and the gross picture of the appendix showed a white solid mass (1.2 cm in greatest diameter; Fig. 1B, arrow). The postoperative histological examination (Figs. 1C and 2AeD) revealed a Grade 1 neuroendocrine tumor (NET G1; carcinoid). Over the past 2 decades the term “carcinoid tumor” has commonly been used for well-differentiated neuroendocrine neoplasms that have a relatively benign prognosis. According to the newest World Health Organization nomenclature and classification of neuroendocrine neoplasms of the digestive system, a typical carcinoid is classified as a Grade 1 neuroendocrine tumor (NET G1). Appendiceal neuroendocrine tumors are rare and one of more unusual histopathological findings (about 0.37%) when examining appendectomy specimens. Nonetheless, they are the

Place de la radiothérapie dans les neurocytomes centraux et revue de la littérature

Neuroendocrine tumors (NETs) are aggressive diseases developing from neuroendocrine cells that most frequently involve the gastro-entero-pancreatic tract and the lung, but more rarely are found in almost all body tissues. Limited biological and clinical data are currently available for NETs in uncommon sites, such as female genital tract. NETs represent 0.9% to 1.5% of the tumors of the uterine cervix. They are more likely to have lymph-vascular space invasion and lymph node involvement, and to develop local and distant relapses when compared with the mostly common cervical squamous cell carcinomas or adenocarcinomas. Positive immunostaining for synaptophysin, chromogranin, CD56, and neuron-specific enolase is often detected in cervical NETs .The most recent editions of the World Health Organization Classification of Gynecologic Tract tumors grouped cervical carcinoid tumor and atypical carcinoid tumor into low-grade NETs and cervical small cell neuroendocrine carcinoma and large cell neuroendocrine carcinoma into high-grade NETs. High-risk HPV DNA is detected in almost all cervical high-grade NETs. No treatment guidelines, based on prospective, well-designed clinical trials, are currently available due to the rarity of these tumors. Many authors have reported different multimodality approaches, mainly derived from NETs of the lung. These usually consist in radical hysterectomy followed by adjuvant chemotherapy or concurrent chemoradiation for early stage disease, definitive concurrent chemoradiation sometimes preceded by neoadjuvant chemotherapy and followed by adjuvant chemotherapy for locally advanced disease, and palliative chemotherapy for metastatic disease. In this systematic review, we address the histologic classification of cervical NETs, analyze their pathogenesis and overall prognosis, and evaluate the different treatment modalities described in the literature, in order to offer a possible algorithm that may help the clinicians in diagnosing and treating patients with these uncommon and aggressive malignancies.

Diagnosis and treatment options of neuroendocrine tumours

Neuroendocrine neoplasms belong to the group of rare tumours. Their clinical importance may be highlighted by their high prevalence despite low incidence. Since survival rate is similar to other progressive neoplastic diseases in metastatic cases, early recognition and appropriate therapy of these neoplasms are equally important. Classification of neuroendocrine tumours is based on their pathologic characteristics according to the 2010 WHO recommendation. Non-functioning tumours cause local symptoms due to their mass effect, while functioning tumours produce well-defined endocrine syndromes. Among laboratory tests, serum chromogranin-A is considered the most important biomarker of both non-functioning and functioning neuroendocrine tumours. Localization of these tumours includes the use of conventional diagnostic imaging, endoscopic examinations, and functional imaging studies. With respect to treatment, elimination of the primary tumour remains one of the most important issues. In advanced cases of the disease metastasectomy, interventional radiologic methods, medical treatment and endoradiotherapy can be used. The aim of this review is to summarize briefly the symptoms, diagnostic methods and treatment options of neuroendocrine tumours.

Tumormikroenvironment in Neuroendokrinen Tumoren (NET) des gastroentero-pankreatischen Systems

Einleitung: Das Tumormikroenvironment neuroendokriner Tumore (NETs), im Hinblick auf die Tumor-Klassifikationen von 2000 und 2010, ist bisher nicht untersucht. Die Beurteilung der Dignität von NETs, allein mithilfe histologischer Kriterien, ist problematisch. Die WHO-Klassifikation von 2000 unterscheidet nicht nur histomorphologisch in gut und wenig differenziert, beurteilt werden auch Tumorgröße, Angioinvasion, Invasion der Musculuaris propria, hormonales Tumorsyndrom, Proliferationsindex (Ki67) sowie vorhandene Metastasen. Die neue WHO-Klassifikation von 2010 vereinheitlicht diese Einteilung und nutzt, unabhängig der Tumorlokalisation und neben der Morphologie, ein Grading-System, in dem nach Proliferationsindex in G1 (Ki67≤2%) niedriggradig maligne, G2 (3 – 20%) intermediärgradig maligne und G3 (> 20%) hochgradig maligne neuroendokrine Neoplasien (NENs) eingeteilt wird.

Ki-67 is a reliable pathological grading marker for neuroendocrine tumors

In neuroendocrine tumors (NETs), proliferation markers, especially Ki-67, have become increasingly important. This study was designed to examine the reproducibility of Ki-67 for use in the current classification of NETs. A retrospectively assembled integrated database with prospectively collected data of patients undergoing multidisciplinary management for NETs from 2000 to 2009 was analyzed. Original pathology was reviewed to reassess Ki-67 values. Ki-67 was then categorized to grades G1 (≤2%), G2 (3-20%), or G3 (>20%) according to the European Neuroendocrine Tumor Society (ENETS) guidelines and the 2010 World Health Organization (WHO) classification. Original Ki-67 values were compared to reviewed values. All statistical analyses were carried out using SAS 9.1.3. A total of 184 patients were included of which 48% were male. The most common primary NET site was the small bowel, in 27%. On pathology review, there was 94% agreement for G1, with 4% of cases upgraded at review to G2 and 2% of cases upgraded to G3. For G2, there was 94% agreement, with 6% of cases downgraded to G1 and 0% upgraded. For G3, there was 90% agreement, with 10% of cases downgraded to G2 and none to G1 (kappa = 0.89). Ki-67 is a proliferative marker for NETs that is highly reproducible when used to grade tumors according to ENETS and WHO categories. The high inter-institutional reliability in the determination of tumor grade as assessed by Ki-67 makes it a reliable tool in the assessment of patients with NETs.

Pathology Reporting of Neuroendocrine Tumors: Essential Elements for Accurate Diagnosis, Classification, and Staging

Much recent debate has focused on the optimal classification of epithelial neuroendocrine tumors (NETs). Multiple different systems of terminology, grading, and staging have been proposed, and some systems combine elements of grade and stage into a single prognostic classification. Recently, national and international consensus groups have attempted to standardize the classification of NETs, especially for those arising in the gastrointestinal tract and pancreas. Furthermore, the recognition that common classification criteria (such as proliferative rate) span multiple different systems allows the basic data necessary to predict outcome and tailor therapy to be included in pathology reports, even though a single uniform system of terminology may remain elusive. Formal tumor-node-metastasis (TNM)-based staging systems also have been developed recently, and advances in the treatment of some NETs (pancreatic in particular) are pointing towards the need to assess therapeutic biomarkers in routine practice. This review will present the most widely used systems for classifying, grading, and staging NETs and will summarize the recommendations for the data to be included in standard pathology reports of these uncommon tumors.

Prolonged Neutropenia after Sunitinib Treatment in a Patient with a Glucagonoma and Multiple Hepatic Metastases

Pancreatic neuroendocrine tumors (PNET) are rare, with approximately 2.2 in 1,000,000 people affected annually. In the classification of neuroendocrine tumors, glucagonomas are a functional PNET and comprise 1.6% of PNET. Glucagonoma syndrome is a paraneoplastic syndrome that is characterized by necrolytic migratory erythema, weight loss, anemia, and diabetes mellitus. Metastatic disease at presentation is common, but is often limited to the liver and regional lymph nodes. Sunitinib malate improves the progression-free and overall survival of PNET. This report presents a 45-year-old Asian woman with prolonged neutropenia after sunitinib treatment of a glucagonoma with multiple hepatic metastases. The severity of the neutropenia after the sunitinib treatment fluctuated from grade 1 to 4 repeatedly, with a non-febrile pattern. Ultimately, the patient did not recover from the neutropenia, even after stopping the sunitinib. (Korean J Med 2013;84:405-410)

Are Neuroendocrine Tumors Going Mainstream?

Are Neuroendocrine Tumors Going Mainstream?

Neoplastic lesions of endocrine cells in the gastrointestinal tract: ten evolving principles as a basis for clinical understanding

Neoplastic lesions of endocrine cells in the gastrointestinal tract: ten evolving principles as a basis for clinical understanding Ben Lawrence,1,2 Malcolm Anderson,3 Simon Schimmack,1 Michael Findlay,2,3 Mark Kidd,1 Irvin Modlin11Department of Surgery, Yale University School of Medicine, New Haven, CT, USA; 2School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, 3Department of Oncology, Auckland District Health Board, Auckland, New ZealandAbstract: Timely and appropriate diagnosis and treatment of patients with gastroenteropancreatic neuroendocrine neoplasms is a difficult clinical endeavor. The field is particularly dynamic, not only in terms of expanding therapeutic options, but in the classifications and biological principles that underpin good decision-making. Acknowledging the confusion created by past changes and the inevitability of future development, we combine our clinical experience with a review of the literature to frame the current understanding of gastroenteropancreatic neuroendocrine neoplasms in terms of a set of principles that have stabilized in the midst of this change. Firstly, we present five principles that guide classification of neuroendocrine neoplasms; specifically principles of prognostic classification, mechanisms of tumorigenesis, undiagnosed disease burden, clues regarding genetic etiology, and typical clinical presentation. Secondly, we offer five clinical principles upon which to build a therapeutic strategy. Specifically, these treatment principles include the separation of options by tumor cell differentiation, and the site of the primary lesion in well differentiated tumors. Chromogranin A is a moderately useful biomarker. Treatment should only be considered by clinicians in a multidisciplinary team, and in the face of multiple potential therapeutic options without a supporting evidence base, clinical trial enrolment remains imperative. Therefore, we provide a current synopsis of classification of gastroenteropancreatic neuroendocrine neoplasms, and their etiology, clinical presentation, and management in a novel framework of ten relatively stable principles.Keywords: gastroenteropancreatic neuroendocrine neoplasms, neuroendocrine tumors, epidemiology, molecular targeted therapy, histopathology, grading, staging, carcinoid, tumorigenesis

Relationship between clinical characteristics and survival of gastroenteropancreatic neuroendocrine neoplasms: A single-institution analysis (1995-2012) in South China.

BackgroundGastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) is the most common type of neuroendocrine tumors accounting for 65–75% of neuroendocrine neoplasms (NENs). Given the fact that there are few studies on GEP-NENs among Chinese patients, we performed a retrospective study in South China.MethodsTotally 178 patients with GEP-NENs treated at the First Affiliated Hospital of Sun Yat-sen University between January 1995 and May 2012 were analyzed retrospectively.ResultsPancreas was found the most common site of involvement (34.8%). 149 patients (83.7%) presented as non-functional tumors with non-specific symptoms such as abdominal pain (33.7%); carcinoid syndrome was not found in this study. Several methods are useful for localization of GEP-NENs, yielding varied detection rates from 77.8% to 98.7%. Positive rates of chromogranin A (CgA) and synaptophysin (Syn) immunhistochemically were 69.1% and 90.2%, respectively. 87 patients (51.5%) had G1 tumors, 31(18.3%) G2 tumors and 51 (30.2%) G3 tumors. Neuroendocrine tumor (NET), neuroendocrine carcinoma (NEC) and mixed adenoendocrine carcinoma (MANEC) were 69.8%, 27.2% and 3.0%, respectively. 28.1% of patients presented with distant disease. Surgery was performed in 152 (85.4%) patients, and overall 5-year survival rate was 54.5%. Functionality, G1 grading and NET classification were associated with favorable prognosis in univariate analysis. Distant metastasis contributed to unfavorable prognosis of these tumors.ConclusionsNonfunctional tumors with non-specific symptoms account for the majority of GEP-NENs. Diagnosis depends on pathological classification. Multidisciplinary treatments could help improve the outcome.

Resection strategies for neuroendocrine pancreatic neoplasms

Due to their rarity and lack of prospective trials, the optimal treatment of pancreatic neuroendocrine neoplasms (PNENs) is still debated. Recommendations gathered by retrospective analyses of patient data should be based on the new classification of neuroendocrine neoplasms. In a retrospective single-center study (1990 to 2012), 127 patients with PNENs were included. Tumor stage and type of resections were analyzed to evaluate successful treatment strategies. Seventy-nine patients (62 %) were diagnosed with stage I or II, 48 patients (38 %) with stage III or IV disease; 49.6 % of all PNENs were nonfunctional. Surgical interventions consisted of 50 enucleations, 27 distal resections, and 2 partial duodenopancreatectomies in patients with stage I or II disease. Twenty-eight patients with stage III or IV disease received a distal resection and in 13 patients, a partial duodenopancreatectomy was carried out. Exploration with debulking was performed in seven patients in stages III and IV. Stage-dependent 10-year survival rates were 93.7 (stages I and II, n = 79) and 56.0 % (stages III and IV, n = 48). PNENs have a good prognosis if they are well-differentiated and resected completely. Organ-preserving resection does not impair the prognosis in selected cases with stage I or II. In case of hepatic metastasis and advanced tumor stage, surgical reduction can reduce symptoms and improve the survival.

Tumeurs neuroendocrines pancréatiques bien différenciées : l’apport des thérapies ciblées

The neuroendocrine pancreatic tumors are rare tumors, but their incidence is constantly rising. Even if the management of these tumors has to be surgical as soon as possible, the disease is most often metastatic at the stage of the diagnostic. The prognostic and the therapeutic options differ from pancreatic adenocarcinoma. Available treatments have evolved over the last years with recent publications of studies that bring to light the benefits of targeted therapies in this pathology. This has resulted in modifications of both practices and either French and international guidelines. Therefore, we focus on the management of the grade 1 and grade 2 well-differentiated neuroendocrine pancreatic tumors as classified in new WHO classification of neuroendocrine neoplasms published in 2010.

Grading of Neuroendocrine Tumors With Ki-67 Requires High-quality Assessment Practices

Gastrointestinal and pancreatic neuroendocrine tumors (NETs) arise from disseminated neuroendocrine cells, expressing general and specific neuroendocrine markers. The World Health Organization 2010 classification of NETs is based on grading them according to the proliferation index (PI), which is determined by immunohistochemical staining of the nuclear antigen Ki-67. The classification introduces Ki-67 as the most important criterion for tumor grading, influencing patients' prognoses and the choice of treatment. The aim of this study was to evaluate the assessment of PI value in NETs and its influence on tumor grading. The tumor material consisted of 51 NETs from the pancreas (n=31) and ileum (n=20). The slides were stained with the Ki-67 antibody and visualized using a polymer kit. PI was assessed visually by microscope oculars and using a public domain image analysis software, ImmunoRatio. The PI was measured from the most proliferative areas of the tumor. The PI values and tumor grade by ImmunoRatio were highly reproducible as compared with conventional assessment, which suffered from variation especially if ascertained by different observers. Computer-aided assessments had almost perfect correlation (r=0.985, r=0.987, and r=0.995) (P=0.000) and reproducibility (κ=0.886, κ=0.886, and κ=1.000) (P=0.000) in PI values and tumor grades, respectively. The PI values and tumor grade between conventional and ImmunoRatio assessments by a qualified observer were in good agreement. ImmunoRatio is a qualified diagnostic aid to more objectively analyze Ki-67 PI-based tumor grade in NETs.

Gastroenteric neuroendocrine neoplasms classification: Comparison of prognostic models

Gastroenteric neuroendocrine neoplasms (GE-NENs) display highly variable clinical behavior. In an attempt to assess a better prognostic description, in 2010, the World Health Organization (WHO) updated its previous classification, and the European Neuroendocrine Tumors Society (ENETS) proposed a new grading and TNM-based staging system. In the current study, the authors evaluated the prognostic significance of these models and compared their efficacy in describing patients' long-term survival to assess the best prognostic model currently available for clinicians. The study cohort was composed of 145 patients with extrapancreatic GE-NEN who were observed from 1986 to 2008 at a single center and were classified according to the WHO and ENETS classifications. Survival evaluations were performed using Kaplan-Meyer analyses on 131 patients. Only deaths from neoplasia were considered. A P value < .05 was considered significant. Prognostic efficacy was assessed by determining the Harrell concordance index (c-index). Both the 2010 WHO and the ENETS classification were able to efficiently divide patients into classes with different prognoses. According to the model comparison, the ENETS TNM-based staging system appeared to be the strongest. All combined models were effective prognostic predictors, but the model that included the 2010 WHO classification plus ENETS staging had a higher c-index. Both the 2010 WHO classification and the ENETS staging system are valid instruments for GE-NENs prognostic assessment, with TNM-based stage appearing to be the best available choice for clinicians, both alone and in association with other classifications.

Well-differentiated grade 3 digestive neuroendocrine tumors: Myth or reality? The PRONET study group.

4129 Background: In contrast to the 2000 World Health Organization (WHO) classification of digestive neuroendocrine tumors (NET) in which morphologic differentiation was the first criterion, the 2010 WHO classification of NET is based mostly on histologic grade. NET are now classified into three main categories: NET G1 (mitotic count &lt;2/10 HPF and/or ≤2% Ki67 index), NET G2 (2-20/10 HPF and/or 3-20%), and neuroendocrine carcinoma (NEC) of small or large cell type. While NET G1 and G2 are well-differentiated tumors, NEC are considered poorly differentiated G3 tumors. We looked at the agreement between grade and differentiation to determine whether all NET can be readily classified according to the 2010 WHO classification. Methods: We designed a 1-year prospective, epidemiologic study to assess the characteristics of newly diagnosed NET, including diagnostic pathology. From August 2010 to July 2011, all pathology laboratories in France were invited to register all incident cases of gastroenteropancreatic (GEP) and thoracic NET, excluding small cell carcinoma. For GEP-NET, investigators were asked to indicate morphologic differentiation (according to WHO 2000) and elements of histologic grade (mitotic index, Ki67 index), according to ENETS. Results: Of 500 invited centers, 80 participated; 1417 incidental cases were included and 77 excluded (duplicates or exclusion criteria), totaling 1340 cases; 778 (58.1%) were GEP-NET; 660/778 (85%) were well differentiated, 72 (9%) poorly differentiated, and 46 (6%) adenocarcinoid, nonclassified, or not evaluable; 422 (54.2%) were G1, 220 (28%) G2, 104 (13.5%) G3, and 32 (4.1%) had missing grades. Of those deemed G3, 72 (69%) were described as poorly differentiated, 21 (20%) as well differentiated (mean Ki67 index 35%, range 25%-60%), and 11 (10.5%) as adenocarcinoid. Conclusions: In this prospective, epidemiologic study, overall agreement between grade and differentiation was good. However, a significant proportion of G3 NET were classified as well differentiated and thus unclassifiable by 2010 WHO classification. This group of tumor deserves to be included in future classifications to help the clinician decide whether they should be treated as NET G1/G2 or NEC G3.

Endocrine carcinoma of the stomach: clinicopathological analysis of 27 surgically treated cases in a single institute

Gastric endocrine carcinoma (EC) is an uncommon tumor of the stomach and the clinical features are not well known. Additionally, the classification and staging systems of this tumor are not yet unified worldwide. In this study, we reviewed 27 patients with gastric EC to evaluate the clinicopathological characteristics of this tumor. We retrospectively reviewed 27 patients with gastric EC among 6466 patients who had undergone gastrectomy between 1986 and 2008 at our institute. Clinicopathological features including immunohistochemistry of Ki-67 were investigated to evaluate the malignant potential of the tumor. Furthermore, survivals were compared between the 7th edition of the International Union Against Cancer (UICC)-TNM (7th TNM) classification for gastric cancer (GC) and the new TNM classification for foregut neuroendocrine tumors (NET). The median survival of the patients was 19.0 months. The 5-year survival rate was 100% in pathological stage (pStage) I, 40% in pStage II, 38% in pStage III, and 11% in pStage IV according to the 7th TNM classification for GC. Survivals by stage showed great difference between the 7th TNM classification for GC and the new TNM classification for foregut NET, but each system correlated with survival. The Ki-67 labeling index was more than 20% in most of the patients. Univariate analysis revealed that maximum tumor diameter, tumor depth, lymph node metastasis, lymphatic invasion, pStage, and curability had significant correlations with survival. Early detection and curative operations are essential for improving the prognosis of gastric EC. However, some adjuvant chemotherapies are required for advanced-stage tumors. Classification and staging systems may need to be unified worldwide for further analysis.