Prognostic value of immunohistochemistry in gastric neuroendocrine (carcinoid) tumors

Gastric Neuroendocrine Tumors (g-NETs): A Systematic Review of the Management and Outcomes of Type 3 g-NETs

PURPOSE

to collect data from real-life experiences of the management of type 3 g-NETs and identify possible prognostic factors that may impact the decision-making process.

METHODS

We performed a systematic review of the literature on type 3 g-NET management using the PubMed, MEDLINE, and Embase databases. We included cohort studies, case series, and case reports written in the English language.

RESULTS

We selected 31 out of 556 articles from between 2001 and 2022. In 2 out of the 31 studies, a 10 mm and 20 mm cut-off size were respectively associated with a higher risk of gastric wall infiltration and/or lymph node and distant metastasis at diagnosis. The selected studies reported a higher risk of lymph node or distant metastasis at diagnosis in the case of muscularis propria infiltration or beyond, irrespective of the dimensions or grading. From these findings, size, grading, and gastric wall infiltration seem to be the most relevant factors in management staff making choices and prognoses of type 3 g-NET patients. We produced a hypothetical flowchart for a standardized approach to these rare diseases.

CONCLUSION

Further prospective analyses are needed to validate the prognostic impact of the use of size, grading, and gastric wall infiltration as prognostic factors in the management of type 3 g-NETs.

Clinicopathological characteristics and prognosis of 77 cases with type 3 gastric neuroendocrine tumours

BACKGROUND

For the rarity of type 3 gastric neuroendocrine tumours (g-NETs), their clinicopathological characteristics and prognosis are not well illustrated.

AIM

To describe the clinicopathological features and outcome of type 3 g-NETs in the Chinese population.

METHODS

Based on the 2019 WHO pathological classification, the clinicopathological characteristics and prognosis of patients with type 3 g-NETs in China were retrospectively analysed.

RESULTS

A total of 77 patients (55.8% of females) with type 3 g-NETs were analysed, with a median age of 48 years (range: 28-79 years). The tumours were mainly located in the gastric fundus/body (83.1%) and were mostly solitary (83.1%), with a median size of 1.5 cm (0.8-3.5 cm). Of these, there were 37 G1 tumours (48.1%), 31 G2 (40.3%), and 9 G3 (11.7%). Ten (13.0%) and 24 (31.2%) patients had lymph node and distant metastasis, respectively. In addition, type 3 g-NETs were heterogeneous. Compared with G1 NETs, G2 NETs had a higher lymph node metastasis rate, and G3 NETs had a higher distant metastasis rate. G1 and G2 NETs with stage I/II disease (33/68) received endoscopic treatment, and no tumour recurrence or tumour-related death was observed within a median follow-up time of 36 mo. Grade and distant metastasis were identified to be independent risk factors for prognosis in multivariable analysis.

CONCLUSION

Type 3 g-NETs are obviously heterogeneous, and the updated WHO 2019 pathological classification may be used to effectively evaluate their biological behaviors and prognosis. Also, endoscopic treatment should be considered for small (< 2 cm), low grade, superficial tumours.

THE ROLE OF CONVENTIONAL ECHOENDOSCOPY (EUS) IN THERAPEUTIC DECISIONS IN PATIENTS WITH NEUROENDOCRINE GASTROINTESTINAL TUMORS

Background:

Gastrointestinal neuroendocrine tumors are rare, usually presented as subepithelial or polypoid tumors. Accurate diagnosis and indication of the type of resection are still challenging.

Aim:

To determine the effectiveness of echoendoscopy in determining the depth of the lesions (T) identified by endoscopy in order to evaluate surgical and/or endoscopic indication, and to evaluate the results of endoscopic removal in the medium term.

Methods:

Twenty-seven patients were included, all of whom underwent echoendoscopy for TN tumor staging and the evaluation of possible endoscopic resection. The parameters were: lesion size, origin layer, depth of involvement and identified perilesional adenopathies. The inclusion criteria for endoscopic resection were: 1) high surgical risk; 2) those with NET <2 cm; 3) absence of impairment of the muscle itself; and 4) absence of perilesional adenopathies in echoendoscopy and in others without distant metastases. Exclusion criteria were TNE> 2 cm; those with infiltration of the muscle itself; with perilesional adenopathies and distant metastases. The techniques used were: resection with polypectomy loop; mucosectomy with saline injection; and mucosectomy after ligation with an elastic band. The anatomopathological study of the specimens included evaluation of the margins and immunohistochemistry (chromogranin, synaptophysin and Ki 67) to characterize the tumor. Follow-up was done at 1, 6 and 12 months.

Results:

Resections with polypectomy loop were performed in 15 patients; mucosectomy in five; mucosectomy and ligation with elastic band in three and the remaining four were referred for surgery. The anatomopathological specimens and immunohistochemical analyzes showed positive chromogranin and synaptophysin, while Ki 67 was less than 5% among all cases. The medium-term follow-up revealed three recurrences. The average size of tumors in the stomach was 7.6 mm and in the duodenum 7.2 mm. Well-demarcated, hypoechoic, homogeneous lesions occurred in 75%; mucous layer in 80%; and the deep and submucosal mucosa in 70%.

Conclusions:

Echoendoscopy proved to be a good method for the study of subepithelial lesions, being able to identify the layer affected by the neoplasm, degree of invasion, echogenicity, heterogeneity, size of the lesion and perilesional lymph node involvement and better indicate the treatment option.

Systematic review: management of localised low-grade upper gastrointestinal neuroendocrine tumours

BACKGROUND

Neuroendocrine tumours (NETs) of the stomach and duodenum are rare, but are increasing in incidence. Optimal management of localised, low-grade gastric and duodenal NETs remains controversial.

AIMS

To systematically review recent literature that has evaluated the management of localised low-grade gastric and duodenal NETs.

METHODS

A systematic literature search was conducted. Articles were screened and eligible articles fully assessed. Additional articles were identified through the included articles' reference lists.

RESULTS

Several relevant retrospective case series were identified, but there was considerable heterogeneity between studies and they reported a variety of parameters. Type I gastric NETs had an excellent prognosis and conservative management approaches such as endoscopic surveillance/resection were appropriate in most cases. Many type III gastric NETs were low grade and appeared to have a better prognosis than has previously been appreciated. Endoscopic rather than surgical resection was therefore effective in some patients who had small, low-grade tumours. Duodenal NETs were more heterogenous. Endoscopic resection was generally safe and effective in patients who had small, low-grade, nonfunctional, non-ampullary tumours. However, some patients, especially those with larger or ampullary duodenal NETs, required surgical resection.

CONCLUSIONS

Most type I gastric NETs behave indolently and surgical resection is only rarely indicated. Some type III gastric and duodenal NETs have a worse prognosis, but selected patients who have small, localised, nonfunctional, low-grade tumours are adequately and safely treated by endoscopic resection. Due to the complexity of this area, a multidisciplinary approach to management is strongly recommended.

[Gastric neuroendocrine tumors]

Gastrointestinal neuroendocrine tumors are rare neoplasms. Currently, incidence of gastric neuroendocrine tumors (gNETs) is being significantly increased. There are 3 groups of gNETs: types I, II and III. Each type has important features regarding clinical picture, prognosis and treatment strategy. Type I is the most common (70-80%) and associated with chronic atrophic gastritis including autoimmune gastritis and Helicobacter associated atrophic gastritis. Type II (5-6%) is associated with multiple endocrine neoplasia type I and Zollinger-Ellison syndrome (MEN I - ZES). Both types are characterized by hypergastrinemia and small tumor dimension. These neoplasms are multiple and mostly benign. On the contrary, NETs type III (10-15%) is not associated with hypergastrinemia and represented by single large neoplasms. Tumors are malignant as a rule. Therefore, surgical resection and chemotherapy are preferred for these tumors. Endoscopic surgery followed by observation is acceptable for almost all NETS type I and II. At the same time, this approach is advisable only for small and highly differentiated neoplasms type III.

Recurrence and metastatic potential in Type 1 gastric neuroendocrine neoplasms

BACKGROUND

The aim of our study was to assess clinico-pathological and biochemical parameters of Type 1 Gastric Neuroendocrine Neoplasms (GNEN1) with respect to tumours propensity for recurrence and metastasis.

METHODS

Hospital charts of GNEN1 patients were reviewed at a single tertiary referral centre.

RESULTS

We included 114 consecutive patients (74 women; age at baseline 54.5 ± 12.7 years [mean ± SD]) with GNEN1. All tumours (n = 114) were well differentiated; Grade 1 (G1) accounted for 56 patients (49%), whereas 46 (40%) were Grade 2 (G2) and 12 (11%) of unknown Grade. Overall follow-up encompassed 45.3 ± 46 (mean ± SD) months in 84 patients who were subjected to annual surveillance; 44 (52%) developed recurrence in the stomach during follow-up with 22 experiencing multiple recurrences; three (2.6%) presented with metastases in locoregional lymph nodes (n = 3) and/or the liver (n = 2); No metastasis or death was reported during follow-up. Median recurrence-free survival (RFS) was 31 months (95% CI: 7.6-54.4). Among clinico-pathological and biochemical parameters investigated, endoscopic intervention compared with surgery (P-value = .009) and higher serum-gastrin levels (s-gastrin) at baseline and first-year follow-up were associated with recurrence (P-value = .022 and .003 respectively) and also shorter RFS (log-rank P = .009 for type of intervention and .014 for s-gastrin, respectively). Receiver Operator Curve analysis of s-gastrin levels at first-year follow-up for recurrence demonstrated an area under the curve of 0.702.

CONCLUSION

Despite the relatively high prevalence of G2 tumours, endoscopically and/or surgically treated GNEN1 remains an indolent disease with a low metastatic propensity and no disease-specific mortality reported in our series. Many patients though will experience local recurrence, warranting long-term endoscopic surveillance with s-gastrin biomarker being a complementary tool in recurrence prediction.

Gastric neuroendocrine neoplasms type 1: A systematic review and meta-analysis

BACKGROUND

To date, the histopathological parameters predicting the risk of lymph node (LN) metastases and local recurrence, associated mortality and appropriateness of endoscopic or surgical resection in patients with gastric neuroendocrine neoplasms type 1 (GNENs1) have not been fully elucidated.

AIM

To determine the rate of LN metastases and its impact in survival in patients with GNEN1 in relation to certain clinico-pathological parameters.

METHODS

The PubMed, EMBASE, Cochrane Library, Web of Science and Scopus databases were searched through January 2019. The quality of the included studies and risk of bias were assessed using the Newcastle-Ottawa Scale (NOS) in accordance with the Cochrane guidelines. A random effects model and pooled odds ratios (OR) with 95%CI were applied for the quantitative meta-analysis.

RESULTS

We screened 2933 articles. Thirteen studies with 769 unique patients with GNEN1 were included. Overall, the rate of metastasis to locoregional LNs was 3.3% (25/769). The rate of LN metastases with a cut-off size of 10 mm was 15.3% for lesions > 10 mm (vs 0.8% for lesions < 10 mm) with a random-effects OR of 10.5 (95%CI: 1.4 -80.8; heterogeneity: P = 0.126; I² = 47.5%). Invasion of the muscularis propria was identified as a predictor for LN metastases (OR: 17.2; 95%CI: 1.8-161.1; heterogeneity: P = 0.165; I² = 44.5%), whereas grade was not clearly associated with LN metastases (OR: 2; 95%CI: 0.3-11.6; heterogeneity: P = 0.304; I² = 17.4%). With regard to GNEN1 local recurrence, scarce data were available. The 5-year disease-specific survival for patients with and without LN metastases was 100% in most available studies irrespective of the type of intervention. Surgical resection was linked to a lower risk of recurrence (OR: 0.3; 95%CI: 0.1-1.1; heterogeneity: P = 0.173; I² = 31.9%). The reported complication rates of endoscopic and surgical intervention were 0.6 and 3.8%, respectively.

CONCLUSION

This meta-analysis confirms that tumor size ≥ 10 mm and invasion of the muscularis propria are linked to a higher risk of LN metastases in patients with GNEN1. Overall, the metastatic propensity of GNEN1 is low with favorable 5-year disease-specific survival rates reported; hence, no clear evidence of the prognostic value of LN positivity is available. Additionally, there is a lack of evidence supporting the prediction of local recurrence in GNEN1, even if surgery was more often a definitive treatment.

GASTRIC NEUROENDOCRINE TUMOR: REVIEW AND UPDATE

INTRODUCTION

The frequency of gastric neuroendocrine tumors is increasing. Reasons are the popularization of endoscopy and its technical refinements. Despite this, they are still poorly understood and have complex management.

AIM

Update the knowledge on gastric neuroendocrine tumor and expose the future perspectives on the diagnosis and treatment of this disease.

METHOD

Literature review using the following databases: Medline/PubMed, Cochrane Library and SciELO. Search terms were: gastric carcinoid, gastric neuroendocrine tumor, treatment. From the selected articles, 38 were included in this review.

RESULTS

Gastric neuroendocrine tumors are classified in four clinical types. Correct identification of the clinical type and histological grade is fundamental, since treatment varies accordingly and defines survival.

CONCLUSION

Gastric neuroendocrine tumors comprise different subtypes with distinct management and prognosis. Correct identification allows for a tailored therapy. Further studies will clarify the diseases biology and improve its treatment.

A 15-year experience with gastric neuroendocrine tumors: Does type make a difference?

BACKGROUND

Gastric neuroendocrine tumors (GNETs) are rare and classified into three types by disease etiology and typical behavior.

METHODS

The aim was to describe outcomes after GNET resection at a single institution from 2000 to 2014, stratified by tumor type. Given the small patient number, P-values were not assigned.

RESULTS

Of 22 patients, 12 patients (55%) had Type 1, none (0%) had Type 2, and 10 (45%) had Type 3 tumors. Compared to Type 3, Type 1 patients were younger (mean age: 52 vs. 59 years) with similar rates of endoscopic resection (25% vs. 20%). Type 1 GNETs often had multiple tumors (60% vs. 10%) and were not poorly differentiated (0% vs. 11%). Only 33% of Type 1 had nodal metastases compared to 71% of Type 3. Type 1 GNETs presented with metastatic disease less often (17% vs. 40%). Three year recurrence-free survival was 33% for Type 1 compared to 86% for Type 3. Disease-specific survival at 3-years was 100% and 75% for Types 1 and 3, respectively.

CONCLUSION

Type 1 GNETs are often indolent and multifocal without nodal involvement, but have high recurrence risk. Type 3 is more aggressive with increased nodal involvement; nodal evaluation should be routinely performed. Determination of GNET type is paramount to treating patients with this rare disease. J. Surg. Oncol. 2016;114:576-580. © 2016 Wiley Periodicals, Inc.

Gastric and duodenal neuroendocrine tumours

Gastric neuroendocrine neoplasms (NENs) are increasing in frequency and have a varied spectrum with regard to histology, clinicopathologic background, stage, and prognosis. They are usually discovered incidentally, are for the most part benign and are associated with hypergastrinaemia (secondary either to chronic atrophic gastritis or rarely Zollinger-Ellison syndrome; types 1 and 2, respectively) or more rarely sporadic type 3. Applications of recent staging and grading systems - namely using Ki-67 proliferative indices - (from ENETS and WHO 2010) can be particularly helpful in further categorising these tumours. The natural history of Type 1 gastric carcinoids is generally (>95%) favourable and simple surveillance is usually recommended for small (<1 cm) T1 tumours, with local (endoscopic or surgical) resection for larger lesions. Other potential therapies such as somatostatin analogues and gastrin receptor antagonists may offer newer therapeutic possibilities. Rarely, gastric NENs have a malignant course and this is usually confined to Type 2 and especially Type 3 tumours; the latter mimic the biological course of gastric adenocarcinoma and require radical oncological therapies. Most duodenal NENs, apart from gastrinomas (that are not dealt with here) are sporadic and non functional. They are also increasing in frequency probably due to incidental discovery at endoscopy or imaging for other reasons and this may account for their overall good prognosis. Peri-ampullary and ampullary NENs may have a more aggressive outcome and should be carefully appraised and treated (often with surgical resection).

Gastric neuroendocrine tumours

BACKGROUND

Gastric neuroendocrine tumours (NETs) are increasingly recognised, and management decisions may be difficult due to an incomplete understanding of aetiology, natural history and optimum therapy. This article presents a current understanding based on recent advances in epidemiology, classification, molecular profiling, and treatment.

METHODS

Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles identified. Selection of articles was based on peer review, journal and relevance.

RESULTS

Gastric NETs may be divided into three clinical prognostic groups: type I is associated with autoimmune atrophic gastritis and hypergastrinaemia, type II is associated with Zollinger-Ellison syndrome, and type III lesions are gastrin-independent, have the greatest metastatic potential and poorest prognosis. There has been an increased frequency of gastric NETs reported. Management approaches have evolved in parallel with advances in endoscopic staging and surgery, as well as improved understanding of the biology and natural history of NETs.

CONCLUSIONS

Gastric NETs present a spectrum of activity from indolent tumours to metastatic malignancy. Treatment decisions for patients must be individualised and are best managed by a multidisciplinary team approach. The current evidence base is limited to small series and efforts to treat patients within clinical networks of expertise are warranted.

Minute type I gastric carcinoid with regional lymph node metastasis

Type I gastric carcinoids are indolent lesions that only rarely metastasize. Until now, lymph node metastasis had only being observed in large (≥10 mm) and usually invasive lesions (deep submucosa or beyond). This study reports a diminutive (8 mm) gastric carcinoid, limited to the superficial layer of the submucosa (sm1), with no angiovascular invasion, but with a high Ki-67 index (7%) and an involved perigastric lymph node. The aggressive behavior of this lesion ends the previous believe that small and superficial type I gastric carcinoids do not metastasize. This case also indicates that better parameters are necessary to evaluate the malignant potential of these lesions and presents a further support to the value of 2010 World Health Organization classification of gastrointestinal neuroendocrine tumors.

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

BACKGROUND

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.

METHODS

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).

RESULTS

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.

CONCLUSION

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.

Review of the pathogenesis, diagnosis, and management of type I gastric carcinoid tumor

Gastric carcinoid tumors comprise 7% of all gastrointestinal carcinoids and have significantly increased in incidence over the past few decades. Seventy to 80% of gastric carcinoids are type I, which usually are clinically asymptomatic and found incidentally at endoscopic evaluation for abdominal pain or anemia. In this review, advances in understanding the pathophysiology of type I gastric carcinoid are highlighted. In addition, various current diagnostic and treatment options are discussed. Although type I carcinoids generally hold a benign course, rigorous investigation is needed to ensure accurate diagnosis and optimal treatment. This includes appropriate diagnostic procedures and imaging and accurate staging of tumor. Tumor size, depth of invasion, presence of metastasis, and the tumor's gastrin dependency dictate treatment options. Appropriate treatments can consist of endoscopic resection, antrectomy, medical management, or frequent follow-up. This article provides a systematic method of evaluating and treating type I gastric carcinoid.

Neuroendocrine tumors involving the gastroenteropancreatic tract: a clinicopathological evaluation of 773 cases

OBJECTIVE

Description of some of the clinical pathological characteristics of neuroendocrine tumors of the gastroenteropancreatic tract in Brazilian patients.

INTRODUCTION

Neuroendocrine tumors arise in many organs and share common pathological features. In 2010, the World Health Organization published a new classification for neuroendocrine tumors using a three-tiered system that applies the terms neuroendocrine tumor Grade 1, neuroendocrine tumor Grade 2, and neuroendocrine carcinoma. The tumor grades are based on their mitotic rate and the Ki-67 index. In Brazil, information on neuroendocrine tumors of gastroenteropancreatic tract is scarce.

METHODS

This study investigated clinicopathological features of 773 Brazilian gastroenteropancreatic neuroendocrine tumor cases from all the geographic regions of Brazil. All of the cases emerged from the files of a single institution (a large pathology reference laboratory) between 1997 and 2009. In addition, the gastroenteropancreatic neuroendocrine tumors were graded according to the new 2010 World Health Organization classification.

RESULTS

Overall there were a higher number of neuroendocrine tumors in female over male. The lower ages were seen in patients with appendiceal tumors. The most common anatomic location involved was stomach followed by small and large intestines. All cases involving the appendix were of grade 1 and 92.1% of the neuroendocrine tumors of the esophagus were neuroendocrine carcinomas (grade 3).

CONCLUSIONS

In this series, the proportion of NET cases in the total number of surgical pathology cases at our institution over the past 12 years is increasing.