ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Tumors: towards a standardized approach to the diagnosis of gastroenteropancreatic neuroendocrine tumors and their prognostic stratification

Differing Clinical Courses and Prognoses in Patients With Gastric Neuroendocrine Tumors Based on the 2010-WHO Classification Scheme

The aim of this study is to test the prognostic accuracy of the 2010-WHO classification for postsurgery survival in nonmetastatic gastric neuroendocrine tumor (NET) cases. Whether the 2010-WHO classification of NETs can predict relapse after surgical resection has not yet been established.We selected 175 nonmetastatic gastric NET patients at Asan Medical Center, Seoul, Korea between 1996 and 2013. All tumors were classified using the WHO-2010 scheme.Among 175 patients with gastric NETs, we diagnosed 39 cases as WHO grade 1, 13 cases as grade 2, 66 cases as grade 3 (neuroendocrine carcinomas; NECs), and 57 cases as mixed with adenocarcinoma. Patients with grade 3 had a lower relapse-free survival (RFS) and overall survival (OS) than those with WHO grade 1/2 and had a lower OS than patients with mixed type tumors. Patients with grade 1/2 had a better OS than patients with mixed type. There was no significant difference in RFS and OS between small and large cell type lesions. Among WHO grade 1/2 patients with ≤1 cm sized lesions, none exhibited lympho-vascular, perineural, mucosal, or submucosal invasion, and we detected no lymph node metastases or recurrences.Our findings strongly suggest that WHO grade 3 behaves more aggressively than adenocarcinoma. Additionally, the survival of cases with large and small cell NEC was similar. Among WHO grade 1/2 patients who had ≤1 cm lesions, none exhibited lympho-vascular, perineural, mucosal, or submucosal invasion and all could be treated by endoscopic resection or minimally invasive surgery without node dissection.

Circulating Transcript Analysis (NETest) in GEP-NETs Treated With Somatostatin Analogs Defines Therapy

CONTEXT

Early and precise delineation of therapeutic responses are key issues in neuroendocrine neoplasm/tumor management. Imaging is currently used but exhibits limitations in sensitivity and specificity. The utility of biomarkers is unclear. objective, setting, and design: This prospective cohort study (11 mo) sought to determine whether measurements of circulating neuroendocrine tumor transcripts (NETest) predict responses to somatostatin analogs (SSAs).

PATIENTS

The test set consisted of 35 SSA-treated gastroenteropancreatic-NETs (RECISTevaluated). The prospective set consisted of 28 SSA-treated Grade 1-Grade 2 GEP-NETs.

INTERVENTION(S)

Whole blood for transcript analysis (NETest) and plasma for Chromogranin A (CgA) (baseline), were collected every 4 weeks (prior to SSA injection). Morphologic (multidetector computed tomography/MRI) and functional imaging ((99m)Tc-[HYNIC, Tyr(3)]-Octreotide) was undertaken at entry and 6-month intervals until progression (RECIST 1.0).

MAIN OUTCOME MEASURE(S)

Treatment response.

RESULTS

Test set: NETest (≥80%; scale, 0-100%) differentiated stable (SD) and progressive (PD) disease (P < .0001). Prospective set: 28 patients (26/28 SD) undergoing standard SSA. Grading: 12 G1, 16 G2. SSA Response: progression-free survival: 315 days: 14 (50%) SD, 14 (50%) PD. NETest: Twenty had elevated (≥80%) values; 14 developed PD; six, SD. CgA: Twelve of 28 exhibited elevated baseline values and/or subsequent >25% increase; eight developed PD; four, SD. NETest (P = .002) and grade (P = .054) were the only factors associated with treatment response. Multiple regression analysis established that the NETest could predict disease progression (P = .0002). NETest changes occurred significantly earlier (146 d prior to progression vs 56 d CgA; P < .0001; χ(2) = 19) and in more patients (100 vs 57%; P < .02).

CONCLUSIONS

NETest values (80-100%) were more accurate and occurred at a significantly earlier time point than CgA and predicted SSA treatment response.

Can pancreatic neuroendocrine tumour biopsy accurately determine pathological characteristics?

BACKGROUND

Assessment of the pathological characteristics of pancreatic neuroendocrine tumours is crucial for appropriate management. We compared preoperative pathological data with surgical specimens for accuracy.

METHODS

Surgical patients with pancreatic neuroendocrine tumours who underwent preoperative endoscopic ultrasound-guided fine needle aspiration of the primary tumour or biopsy of liver metastasis were retrospectively included. Tumour differentiation and the Ki67 proliferation index on biopsies were compared with pancreatic specimens.

RESULTS

Fifty-seven patients were included. A preoperative biopsy of the primary tumour or of a liver metastasis was obtained in 48 and 9 patients respectively. Tumour differentiation was high in 98%, and poor in 2% on biopsy and high in 100% of surgical specimens. Ki67 index values were 0 (0-19) and 2 (0-15) on biopsy and surgical specimens (p=0.01). Correlation between preoperative and surgical findings was stronger for liver (r=0.62, p=0.001) than for pancreas (r=0.23, p=0.11). Correlation for pancreas varied according to the tumour pattern: solid (r=0.24, p=0.16), mixed (r=0.91, p=0.0036) or cystic (r=0.04, p=0.89). Tumour grade was different between pancreatic biopsies and surgical specimens, for grade 1 (63% vs 37%) and grade 2 (28% vs 72%), p=0.0007.

CONCLUSIONS

Tumour grade assessment is accurate in biopsies of liver metastases of pancreatic neuroendocrine tumours, while pancreatic fine-needle aspiration biopsies are less accurate.

Neuroendocrine tumor G3: a pancreatic well-differentiated neuroendocrine tumor with a high proliferative rate

A 68-year-old man was referred to our hospital because of left upper quadrant pain. Contrast enhanced computed tomography showed a low density mass with delayed contrast effects as well as para-aortic node swelling with homogenous contrast effects. Histological examination of specimens obtained by endoscopic ultrasound fine needle aspiration revealed a pancreatic neuroendocrine tumor (NET) G2, according to the World Health Organization 2010 classification, and lymph node metastasis. Distal pancreatectomy and lymph node dissection were performed. On histological examination, the tumor showed well-differentiated morphology with an organoid pattern. The Ki67 labeling index was 21.6 %, and the mitotic count was 25/10 high power fields. As mentioned above, we made a final diagnosis of the lesion as "NET G3," because the tumor presented with well-differentiated morphology. Chemotherapy with Everolimus was administered. Liver metastasis occurred 11 months after the first operation, and a partial hepatectomy was performed. Histological findings were similar to those of the first operation. Herein we present a case of pancreatic well-differentiated neuroendocrine tumor with a high proliferative rate referred to as "NET G3," and review the relevant literature.

A retrospective review of diagnosis and treatment modalities of neuroendocrine tumors (excluding primary lung cancer) in 10 oncological institutions of the East German Study Group of Hematology and Oncology (OSHO), 2010-2012

RATIONALE

There is a paucity of data on the incidence of neuroendocrine tumors (NET) outside pulmonary primaries and on treatment modalities applied to patients with NET in clinical practice. Only very little therapeutic progress has been made with respect to response and overall survival, particularly among patients with poorly differentiated, WHO grade 3 neuroendocrine carcinomas (G3-NEC). We sought to document the incidence and treatment modalities in patients with NET/NEC within a period of 2 years.

METHODS

We conducted a retrospective data analysis using a simple documentation file to be completed in written form or electronically, including localization, WHO grading, treatment modalities, and specific therapeutic regimens applied. Primary lung cancer was excluded. The time period to be covered was 2010 through 2012. Individual patient data such as names or age were not documented, so that no ethics committee approval was required.

RESULTS

Ten different hospital- or practice-based institutions contributed their data. One to 35 patients were documented per institution, summing up to 149 patients with 154 tumor localizations. Midgut (n = 46), foregut (n = 42), hindgut (n = 17), lung (n = 9), bladder (n = 8), unknown primary (n = 11), and other including prostate and liver (n = 21) were documented as tumor sites. Histological gradings were G1 (n = 71), G2 (n = 27), G3 (n = 34), undifferentiated "G4" (n = 4), and not specified (n = 13). Treatment modalities were surgical resection (n = 102), chemotherapy (n = 49), somatostatin analogs (n = 39), radiotherapy (n = 22), receptor-directed radionuclide therapy (n = 12), and systemic tyrosine kinase inhibition (n = 5). Chemotherapy was given to patients not only with G3-NEC (n = 31), but also with G2 (n = 12) and G1 NET (n = 7). Somatostatin analogs as well as receptor-directed radionuclides were applied to patients throughout all gradings.

CONCLUSIONS

NET and NEC are not very rare tumor entities, but are diagnosed with very different frequencies, possibly depending upon the alertness of pathologists and clinicians. Chemotherapy, receptor-directed radionuclide application, and somatostatin analog therapy are applied without a clear correlation to different histologic gradings. Diagnostic and therapeutic progress in the field of NETs/carcinomas is urgently needed.

Somatostatin and dopamine receptor expression in neuroendocrine neoplasms: correlation of immunohistochemical findings with somatostatin receptor scintigraphy visual scores

CONTEXT

The expression of somatostatin (sstr1-5) and dopamine (DR) receptors in neuroendocrine neoplasms (NENs) facilitates diagnosis by tumour visualization with somatostatin receptor scintigraphy (SRS) and directs towards specific treatment with peptide receptor radionuclide therapy (PRRT) with radiolabelled somatostatin analogues.

OBJECTIVE

To investigate the co-expression of sstrs, D2R in relation to pre-operative SRSs in NENs.

DESIGN

Prospective two-centre study.

PATIENTS AND MEASUREMENTS

We analysed pre-operative SRS of 60 patients [44 with gastrointestinal (GI) NENs and 16 with lung NENs] and compared SRS results with immunohistochemical (IHC) reactivity for sstr2, sstr3, sstr5 in sample tissues from primary (n = 54) and metastatic (n = 27) lesions and IHC reactivity for D2R in 23 samples from primary GI-NENs lesions.

RESULTS

Sstr2 was the commonest sstr expressed (65·4%) and was co-expressed with sstr3 and sstr5 in 32·1% and 24·7% of the specimens, respectively. In 67 of 81 specimens (82·7%), there was concordance of sstr2 immunohistochemistry with SRS findings (P < 0·001). D2R was expressed in only 8 of 23 (34·8%) GI-NENs while was co-expressed with sstr2 in all cases. SRS grade, as per Krenning scale, was higher in metastatic foci, large-size (>2 cm) tumours and GI-NENs, whereas sstr2 intensity was greater in GI compared to lung NENs. SRS grade showed higher correlation with sstr2 (r = 0·6, P < 0·001) and D2R (r = 0·5, P < 0·001) IHC intensity scores than tumour size (r = 0·4, P < 0·001) and sstr3 (r = 0·4, P < 0·001) intensity score.

CONCLUSIONS

Sstr2 IHC expression and SRS are useful tools for the diagnosis and management of NENs because they display a high concordance. IHC expression of DR2 seems to be of potential clinical significance in GI-NENs tumours.

Parenchyma-sparing pancreatectomies for pancreatic neuroendocrine tumors

Parenchyma-sparing pancreatectomy, including enucleation and central pancreatectomy, has been investigated as an alternative to standard resection (pancreaticoduodenectomy or left/distal pancreatectomy) for pancreatic neuroendocrine tumor (PNET). In selected patients, with small (<2 cm) and low-grade tumors, PSP are associated with excellent both overall and disease-free survivals. These procedures are associated with an increased postoperative morbidity but an excellent long-term postoperative pancreatic function. Therefore, they should be considered as a valid therapeutic option in selected well-differentiated PNET.

Clinicopathological features and survival analysis of gastroenteropancreatic neuroendocrine neoplasms: a retrospective study in a single center of China

OBJECTIVE

To investigate the clinicopathological features, survival and prognostic factors for gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) in a Chinese population.

METHODS

We investigated 154 consecutive patients (88 males, 66 females; median age 56 years, age range 9-86 years) diagnosed with GEP-NENs between 2001 and 2013 at The Affiliated Hospital of Qingdao University. Demographic, clinical and pathological variables and survival data were retrieved.

RESULTS

The pancreas was the most common site of involvement (63/154, 40.9%). Tumor size varied from 0.3 to 16.0 cm (median, 1.2 cm). The patients were followed up for a median period of 22 months (range, 1-157 months). The estimated 3- and 5-year overall survival (OS) rates for all patients were 84.0% and 81.9%, respectively. Multivariate analysis showed that larger tumor size, lymphatic metastases and distant metastases were significant predictors for poor survival outcome.

CONCLUSIONS

Our data provide further information on the clinicopathological features of GEP-NENs in China. Additionally, we identified tumor size, lymphatic metastases and distant metastases as independent prognostic factors for long-term survival.

Radiofrequency ablation for neuroendocrine liver metastases: a systematic review

To determine the efficacy of radiofrequency (RF) ablation in neuroendocrine tumor (NET) liver metastases. A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eight studies were included (N = 301). Twenty-six percent of RF ablation procedures were percutaneous (n = 156), with the remainder conducted at surgery. Forty-eight percent of patients had a concomitant liver resection. Fifty-four percent of patients presented with symptoms, with 92% reporting symptom improvement following RF ablation (alone or in combination with surgery). The median duration of symptom improvement was 14-27 months. However, recurrence was common (63%-87%). RF ablation can provide symptomatic relief in NET liver metastases alone or in combination with surgery.

CTNNB1 mutational analysis of solid-pseudopapillary neoplasms of the pancreas using endoscopic ultrasound-guided fine-needle aspiration and next-generation deep sequencing

BACKGROUND

Solid-pseudopapillary neoplasm (SPN), a rare neoplasm of the pancreas, frequently harbors mutations in exon 3 of the cadherin-associated protein beta 1 (CTNNB1) gene. Here, we analyzed SPN tissue for CTNNB1 mutations by deep sequencing using next-generation sequencing (NGS).

METHODS

Tissue samples from 7 SPNs and 31 other pancreatic lesions (16 pancreatic ductal adenocarcinomas (PDAC), 11 pancreatic neuroendocrine tumors (PNET), 1 acinar cell carcinoma, 1 autoimmune pancreatitis lesion, and 2 focal pancreatitis lesions) were analyzed by NGS for mutations in exon 3 of CTNNB1.

RESULTS

A single-base-pair missense mutations in exon 3 of CTNNB1 was observed in all 7 SPNs and in 1 of 11 PNET samples. However, mutations were not observed in the tissue samples of any of the 16 PDAC or other four pancreatic disease cases. The variant frequency of CTNNB1 ranged from 5.4 to 48.8 %.

CONCLUSIONS

Mutational analysis of CTNNB1 by NGS is feasible and was achieved using SPN samples obtained by endoscopic ultrasound-guided fine needle aspiration.

Clinicopathological features and prognosis of gastroenteropancreatic neuroendocrine tumors: analysis from a single-institution

BACKGROUND

The gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) is the most common type of neuroendocrine neoplasm. We summarized data in our centre to investigate the clinicopathological features, diagnostic methods, therapeutic approaches and prognosis for this neoplasm to increase knowledge of this disease in Asian populations.

METHOD

A total of 122 patients treated at Sun Yet-san Memorial Hospital of Sun Yat-sen University between January 2000 and December 2011 were analyzed retrospectively.

RESULTS

Pancreas was the most common site of involvement (65/122, 53.3%); this disease has no special symptoms; positive rates of chromogranin A (CgA) and synaptophysin (Syn) were 81.1% and 87.7%, respectively. The positive rate of Syn had statistical difference among the three grades, but not CgA. Some 68 patients had G1 tumors, 32 G2 tumors and 22 G3 tumors, and Chi-square test showed that higher grading was correlated with worse prognosis (χ2=32.825, P=0.0001). A total of 32 patients presented with distant metastasis, and 8 cases emerged during following up. Cox proportional hazards regression modeling showed that the tumor grade (P=0.01), lymphatic metastasis (P=0.025) and distant metastasis (P=0.031) were predictors of unfavorable prognosis. The overall 5-year survival rate was 39.6%, the 5-year survival rate of G1 was 55.7%, and the G2 and G3 were 34.2% and 0%, respectively.

CONCLUSIONS

The incidence of gastroenteropancreatic neuroendocrine tumors has risen over the last 12 years. All grades of these diseases metastasize readily, and further research regarding the treatment of patients after radical surgery is needed to prolong disease-free survival.

[Neuroendocrine neoplasms of the distal jejunum and ileum]

Neuroendocrine neoplasms (NEN) of the distal jejunum and ileum derive from serotonin-producing enterochromaffin (EC) cells. Due to their low proliferation rate and their infiltrative growth, they are often discovered at an advanced disease stage when metastasis has already occurred. The biology of these tumours is different from other NEN of the digestive tract. In order to standardise and improve diagnosis and therapy, the guidelines for the diagnosis and clinical management of jejuno-ileal NEN as well as for the management of patients with liver and other distant metastases from NEN were revised by the European Neuroendocrine Tumour Society (ENETS) in 2012. This review focuses on aspects relevant for surgical pathology.

Somatostatin Receptors 2A and 5 Are Expressed in Merkel Cell Carcinoma with No Association with Disease Severity

BACKGROUND/AIMS

Merkel cell carcinoma (MCC) is a rare high-grade neuroendocrine tumour of the skin. It has been speculated that MCCs express somatostatin receptors (SSTRs), but this has never been assessed in a large series of MCCs. The main aim of this study was to assess the expression of SSTR2A and SSTR5 in MCC tumours. The secondary aims were to assess whether expression of SSTR was associated with the Ki67 proliferative index, Merkel cell polyomavirus (MCPyV) status, clinical characteristics and outcome.

METHODS

Clinical data and tumours were collected from an ongoing cohort of French patients with MCC. Immunohistochemistry was performed with anti-SSTR2A and anti-SSTR5 monoclonal antibodies, and tumours were classified into 3 groups: 'no expression', 'low expression' and 'moderate expression' using an SSTR staining score.

RESULTS

SSTR expression was assessed for 105 MCC tissue samples from 98 patients, and clinical characteristics were available for 87 of them. SSTR expression was consistent between the primary skin tumour and the corresponding metastases for SSTR2A and SSTR5 in 3/7 and 6/7 cases, respectively. SSTR2A and SSTR5 were expressed in 58 cases (59.2%) and in 44 cases (44.9%), respectively. Overall, at least one SSTR was expressed in 75 tumours (76.5%). SSTR expression was not associated with clinical characteristics, Ki67 proliferative index, recurrence-free survival or MCC-specific survival. Expression of SSTR2A was associated with MCPyV status in MCC tumours but not SSTR5.

CONCLUSION

SSTRs were expressed in a high proportion of MCCs, although expression was heterogeneous between tumours and was not associated with disease severity.

Novel prognostic markers revealed by a proteomic approach separating benign from malignant insulinomas

The prognosis of pancreatic neuroendocrine tumors is related to size, histology and proliferation rate. However, this stratification needs to be refined further. We conducted a proteome study on insulinomas, a well-defined pancreatic neuroendocrine tumor entity, in order to identify proteins that can be used as biomarkers for malignancy. Based on a long follow-up, insulinomas were divided into those with metastases (malignant) and those without (benign). Microdissected cells from six benign and six malignant insulinomas were subjected to a procedure combining fluorescence dye saturation labeling with high-resolution two-dimensional gel electrophoresis. Differentially expressed proteins were identified using nano liquid chromatography-electrospray ionization/multi-stage mass spectrometry and validated by immunohistochemistry on tissue microarrays containing 62 insulinomas. Sixteen differentially regulated proteins were identified among 3000 protein spots. Immunohistochemical validation revealed that aldehyde dehydrogenase 1A1 and voltage-dependent anion-selective channel protein 1 showed significantly stronger expression in malignant insulinomas than in benign insulinomas, whereas tumor protein D52 (TPD52) binding protein was expressed less strongly in malignant insulinomas than in benign insulinomas. Using multivariate analysis, low TPD52 expression was identified as a strong independent prognostic factor for both recurrence-free and overall disease-related survival.

Grading of EUS-FNA cytologic specimens from patients with pancreatic neuroendocrine neoplasms: it is time move to tissue core biopsy?

Pancreatic neuroendocrine neoplasms (p-NENs) are rare and characterized by an indolent course, with a much better prognosis than non-neuroendocrine tumors of the pancreas. In the non-functional class of p-NENS, surgery remains the only curative treatment for early localized disease, but there are few therapeutic options for advanced disease. The prognosis of non-functional p-NENs is determined by many clinical criteria. In 2010, however, the World Health Organization (WHO) introduced a grading system in which determination of the Ki-67 proliferative index has become essential with key role in determining therapeutic decision in both advanced and early diseases. Conventionally, Ki-67 has been assessed on surgical specimens. In last decade, however, the availability of EUS-guided fine needle aspiration (EUS-FNA) has provided the opportunity to sample pancreatic lesions and to assess the value of this parameter pre-operatively. The few studies reporting the use of EUS-FNA cytological specimens for Ki-67 measurement showed promising results. As shown by Weynand and colleagues FNA-cytology may underestimate the staging and caution in using this method to classify tumors as low-grade (G1) should be adopted. Thus, Ki-67 expression on cytological specimens remains unsatisfactory and the need for tissue biopsy specimens has been strongly advocated. Based on a recent study that has reported a high concordance of EUS-guided core biopsy for histologic examination and surgical specimens, especially when a cut-off of 5% is used to differentiate G1 and G2 tumors, EUS tissue acquisition by core biopsy is ready for prime time and should be adopted as a standard of practice.

Chromogranin A as a marker for diagnosis, treatment, and survival in patients with gastroenteropancreatic neuroendocrine neoplasm

Chromogranin A (CgA) not only plays an important role in pathologic diagnosis, but is also used as a circulating biomarker in patients with gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN). However, the relationship between immunohistochemistry (IHC) expression and serum levels of CgA has not been investigated. The value of CgA for evaluating treatment response and prognosis is still not well understood. We conducted this study to assess the significance of CgA in GEP-NEN in terms of diagnosis, curative effects evaluation and prognosis. One hundred forty-five patients comprising 88 patients with active disease and 57 disease-free patients were enrolled in this study from January 2011 to November 2013. The expression of CgA was assessed by IHC, and serial serum CgA levels were measured by enzyme linked immunosorbent assay. The overall expression rate of CgA was 69.0% (100/145). CgA expression was associated with tumor site and stage (P < 0.05), but not correlated with prognosis (P = 0.07). Serum CgA levels were significantly higher in GEP-NEN patients with active disease when compared with disease-free patients (P = 0.001) or healthy participants (P < 0.001). A CgA cutoff value of 95 ng/ml discriminated between healthy subjects or disease-free patients and patients with active disease (sensitivity 51.2% and specificity 87.5%, respectively). There was a correlation between the CgA IHC expression and high serum CgA levels (R = 0.320, P = 0.002). Serum CgA levels were much higher in patients who classified as neuroendocrine carcinoma, mixed adenoendocrine carcinoma (P = 0.035) and who were on stage IV (P = 0.041). Changes in CgA levels normalization or ≥ 30% decrease suggested that patients had tumor response. Furthermore, patients with serum CgA levels higher than 95 ng/ml had a significantly shorter survival compared with patients with levels lower than 95 ng/ml (P < 0.001). CgA is a reliable pathologic and circulating maker for diagnosis of GEP-NEN. We further confirmed that serial measurement of CgA may be useful for evaluating the efficacy of different kinds of therapies in patients during follow-up, and serum CgA level ≥ 95 ng/ml may serve as a predictor of overall survial.

[Gastroenteropancreatic neuroendocrine neoplasms. Role of biopsies]

Neuroendocrine neoplasms of the pancreas and the gastrointestinal tract are heterogeneous regarding etiology (e.g. sporadic or hereditary), histomorphology, hormone expression, hormone-related functional activity and especially the malignant potential. In neuroendocrine neoplasms the biopsy-based diagnosis plays an important role for the clinical management of patients. The diagnosis most importantly relies on the differentiation (e.g. organoid versus diffuse growth patterns) and the grading of tumors. The latter is based on the proliferation activity as determined by Ki-67 immunostaining and mitotic count and results in the current tumor classification into neuroendocrine tumors G1, neuroendocrine tumors G2 or neuroendocrine carcinomas G3. Occasionally, tumors may show mixed differentiation containing a non-neuroendocrine cancer component. The neuroendocrine markers synaptophysin and chromogranin A are recommended for the immunohistochemical confirmation of the diagnosis. Furthermore, biopsy material can be used to investigate the expression of therapy-related markers, such as somatostatin receptor-2A. Moreover, if needed, the expression of transcription factors and hormones can be determined to obtain information on the possible site of origin of metastatic neuroendocrine neoplasms or to determine the syndrome-inducing hormone in functionally active neuroendocrine neoplasms. Finally, using the stomach as an example, biopsies may also be successfully used to investigate neuroendocrine precursor lesions which may harbor prognostic significance.

The usefulness of endoscopic ultrasound-guided fine-needle aspiration for the diagnosis of pancreatic neuroendocrine tumors based on the World Health Organization classification

BACKGROUND

We assessed the controversial topic of using 22-gauge needles in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for the diagnosis and evaluation of Ki67 labeling indices (Ki67LI) of pancreatic neuroendocrine tumors (pNET).

METHODS

Thirty-eight patients with pNET who underwent EUS-FNA between January 1, 2008 and December 31, 2012 were enrolled in this study. When available, the Ki67LI and WHO classifications obtained by EUS-FNA and surgical resection were compared.

RESULTS

EUS-FNA with a 22-gauge needle acquired sufficient histological sample to correctly diagnose pNET in 35 cases (92.1%). Both EUS-FNA and surgical histological specimens were available for 19 cases, and grading classes of the 2 procedures were consistent in 17 cases (89.5%) according to the WHO classification based on the Ki67LI. Tumor size was associated with a difference in the Ki67LI between the 2 procedures, although the Ki67LI was almost completely consistent for tumors less than 18 mm in size.

CONCLUSIONS

EUS-FNA with a 22-gauge needle is a safe and highly accurate technique for the diagnosis of pNET. There was a clear correlation between the Ki67LI of histological specimens acquired by EUS-FNA and surgery. EUS-FNA with a 22-gauge needle is useful to predict the WHO classification of pNET.

Laparoscopic and endoscopic cooperative surgery for duodenal neuroendocrine tumor (NET) G1: Report of a case

•

Endoscopic treatment is generally recommended for G1 NETs <10 mm in diameter and extending only to the submucosal layer in gastrointestinal tract.

•

Some cases are difficult to resect endoscopically in duodenal tumor because the wall is thinner than that of stomach, and endoscope maneuverability is limited within the narrow working space.

•

We resected duodenal NET G1 using LECS technique and we demonstrated that LECS is a safe and feasible procedure for duodenal G1 NETs.

INTRODUCTION

We report a case of duodenal neuroendocrine tumor (NET) G1 resected by laparoscopic and endoscopic cooperative surgery (LECS) technique.

PRESENTATION OF CASE

A 58-year-old woman underwent esophagastroduodenoscopy, revealing an 8-mm, gently rising tumor distal to the pylorus, on the anterior wall of the duodenal bulb. Endoscopic ultrasonography suggested the tumor might invade the submucosal layer. The tumor was pathologically diagnosed as a G1 duodenal NET, by biopsy. Endoscopic submucosal dissection was attempted, but was unsuccessful because of the difficulty of endoscopically performing an inversion operation in the narrow working space. The case was further complicated by the patient's duodenal ulcer scar. We performed a full-thickness local excision using laparoscopic and endoscopic cooperative surgery. The tumor was confirmed and endoscopically marked along the resection line. After full-thickness excision, using endoscopy and laparoscopy, interrupted full-thickness closure was performed laparoscopically.

DISCUSSION

Endoscopic treatment is generally recommended for G1 NETs <10 mm in diameter and extending only to the submucosal layer. However, some cases are difficult to resect endoscopically because the wall of duodenum is thinner than that of stomach, and endoscope maneuverability is limited within the narrow working space. LECS is appropriate for early duodenal G1 NETs because they are less invasive and resection of the lesion area is possible.

CONCLUSION

We demonstrated that LECS is a safe and feasible procedure for duodenal G1 NETs in the anterior wall of the first portion of the duodenum.

Therapy for metastatic pancreatic neuroendocrine tumors

BACKGROUND

Pancreatic neuroendocrine tumors (pNETs) are frequently malignant (50-80%, except for insulinoma) and may show an aggressive course with metastases to the liver as well as more distant sites. These heterogeneous neoplasms include functioning tumors, which secrete a variety of peptide hormones, and non-functioning tumors (up to 90% of pNETs), which often show metastases at the time of diagnosis.

METHODS

A PubMed search was performed for English-language publications from 1995 through December 2012. Reference lists from studies selected were manually searched to identify further relevant reports. Manuscripts comparing different therapeutic options and advances for metastatic pNETs were selected.

RESULTS

The therapeutic options for metastatic pNETs are expanding and include surgery, which remains the only curative approach, liver-directed therapies, and medical therapy. In selected cases also liver transplantation (OLT) may be considered. The option of OLT for metastatic disease is unique to neuroendocrine tumors. Recently, novel promising targeted therapies have been proposed for progressive well-differentiated pNETs.

CONCLUSIONS

The best therapeutic approach for pNETs is still matter of debating. However, since pNETs often show a more indolent behavior compared to other malignancies, the preservation of the quality of life of the patient and the personalization of the therapy according to tumor's and patient's features are mandatory.

Parathyroid hormone-related peptide (PTHrP) secretion by gastroenteropancreatic neuroendocrine tumors (GEP-NETs): clinical features, diagnosis, management, and follow-up

CONTEXT

Only a small number of case reports has been published on patients with PTHrP-hypersecreting metastatic gastroenteropancreatic (GEP) neuroendocrine tumors (NETs).

OBJECTIVE

The objective of this study was to evaluate the clinical, biochemical, and radiological features, management, and treatment outcome of patients with PTHrP-hypersecreting GEP-NETs.

DESIGN

Retrospective case series.

SETTING

Tertiary referral hospital.

MAIN OUTCOME MEASURES

Clinical, biochemical, and radiological features were measured, as well as response to therapy and survival.

PATIENTS

Ten patients with PTHrP-secreting GEP-NETs (nine pancreatic and one unknown primary) with a median age of 50.4 years (range, 38.3-61.1) were studied. Multiple endocrine neoplasia type 1 patients were excluded.

RESULTS

The median follow-up was 57.2 months (range, 11.6-204.5 mo). Median overall survival was 86.0 months. In total, 51 different treatment interventions and combinations were applied. In seven of the 10 patients, somatostatin analog (SSA) treatment resulted in a temporary normalization of serum calcium levels with a long-term response observed in two patients (up to 35.2 mo). Peptide receptor radiotherapy (PRRT) with radiolabeled SSAs induced long-term responses ranging from 9.0-49.0 months in four of six patients treated with PRRT.

CONCLUSIONS

Hypersecretion of PTHrP by metastatic GEP-NETs is very rare and seems to be exclusively associated with metastatic pancreatic NETs. PTHrP production has major clinical impact because poorly controllable hypercalcemia is associated with increased morbidity and mortality. The most successful treatment options for PTHrP-producing GEP-NETs are SSAs and PRRT using radiolabeled SSAs. Isotonic saline and bisphosphonates can be considered as supportive therapies.

Observational study of patients with gastroenteropancreatic and bronchial neuroendocrine tumors in Argentina: Results from the large database of a multidisciplinary group clinical multicenter study

Neuroendocrine tumors (NET) include a spectrum of malignancies arising from neuroendocrine cells throughout the body. The objective of this clinical investigation of retrospectively and prospectively collected data was to describe the prevalence, demographic data, clinical symptoms and methods of diagnosis of NET and the treatment and long-term follow-up of patients with NET. Data were provided by the participating centers and assessed for consistency by internal reviewers. All the cases were centrally evaluated (when necessary) by the pathologists in our group. The tissue samples were reviewed by hematoxylin and eosin and immunohistochemical staining techniques to confirm the diagnosis of NET. In total, 532 cases were documented: 461 gastroenteropancreatic-NET (GEP-NET) and 71 bronchial NET (BNET). All the tumors were immunohistochemically defined according to the World Health Organization (WHO) and European Neuroendocrine Tumor Society criteria. The most common initial symptoms in GEP-NET were abdominal pain, diarrhea, bowel obstruction, flushing, gastrointestinal bleeding and weight loss. The most common tumor types were carcinoid (58.0%), non-functional pancreatic tumor (23.0%), metastatic NET of unknown primary (16.0%) and functional pancreatic tumor (3.0%). Of the BNET, 89.0% were typical and 11.0% atypical carcinoids. Of the patients with GEP-NET, 59.2% had distant metastasis at diagnosis. The locations of the primary tumors in GEP-NET were the small bowel (26.9%), pancreas (25.2%), colon-rectum (12.4%), appendix (7.6%), stomach (6.9%), esophagus (2.8%), duodenum (2.0%) and unknown primary (16.3%). The histological subtypes based on the WHO classification were well-differentiated NET (20.1%), well-differentiated neuroendocrine carcinomas (66.5%) and poorly differentiated neuroendocrine carcinomas (10.3%). Overall, 67.3% of the patients underwent surgery, 41.2% with curative intent and 26.1% for palliative purposes. The 5-year survival rates were 65.1% (95% confidence interval, 58.0-71.4%) in GEP-NET and 100.0% in typical carcinoid of the lung. This observational, non-interventional, longitudinal study aimed to accumulate relevant information regarding the epidemiology, clinical presentation and current practices in the treatment of NET patients in Argentina, providing insight into regional differences and patterns of care in this heterogeneous disease.

Power Doppler endoscopic ultrasound for the assessment of pancreatic neuroendocrine tumors

OBJECTIVE

Pancreatic neuroendocrine tumors (PNET) represent rare, heterogeneous tumors with clinical, imaging and treatment particularities. The aim of this study was to assess the role of power Doppler endoscopic ultrasound (EUS) in the diagnosis and characterization of PNET.

METHODS

All consecutive patients with PNET assessed by power Doppler EUS in the Research Centre of Gastroenterology and Hepatology Craiova, Romania, in the past 51 months were included in the study. All EUS examinations were performed initially in gray-scale mode, followed by power Doppler mode examinations, before and after contrast-enhancement. Each recorded EUS movie was further subjected to post-processing using a computer-enhanced dynamic analysis using a special plug-in which permitted assessment of vascularity index (EUS-VI).

RESULTS

Based on the analysis of all consecutive malignant focal pancreatic masses diagnosed in the study period, a total number of 131 consecutive patients were included: 14 patients with pancreatic neuroendocrine tumors and 117 patients with pancreatic adenocarcinoma. The sensitivity of the pre-contrast EUS-VI for the diagnosis of PNET was 71.43%, similar to EUS-FNA. After contrast enhancement, the EUS-VI is also higher in PNET (27.07%) as compared to pancreatic adenocarcinoma where it was significantly lower 9.82% (P < 0.001). However, the sensitivity of EUS-VI after contrast enhancement for the diagnosis of PNET was 100%, higher than pre-contrast EUS-VI, with an acceptable specificity (79.49%) and better accuracy (81.68%).

CONCLUSION

Power Doppler EUS represents a useful method in the initial assessment of PNET. Using evaluation of vascularity through EUS-VI, the differentiation between PNET and pancreatic cancer could be possible, especially in the subgroup of patients where EUS-guided fine needle aspiration is falsely negative.

Incidence of gastroenteropancreatic neuroendocrine tumours: a systematic review of the literature

Based on the current medical literature, the worldwide incidence of neuroendocrine tumours (NETs) seems to have increased; however, a systematic literature overview is lacking. This study aimed to collect all available data on the incidence of gastroenteropancreatic (GEP)-NETs and characteristics of population to establish their epidemiology. A sensitive MEDLINE search was carried out. The papers were selected via a cascade process that restricted the initial pool of 7991 articles to 33, using predefined inclusion and exclusion criteria. Original articles evaluating the incidence of sporadic GEP-NETs in regional, institutional and national registries were considered. The majority of data originated from the US National Cancer Institute Surveillance, Epidemiology and End Results database and from national cancer registries in Western Europe. Generally, because of the retrospective nature of existing databases the outcomes of studies might be biased, which hinders the drawing of firm conclusions. The age-adjusted incidence of GEP-NETs has increased steadily over the past four decades (1973-2007), increasing 3.65-fold in the USA and 3.8- to 4.8-fold in the UK. Incidence has changed variably from one anatomical site to another. The greatest increase in incidence occurred for gastric and rectal NETs, while the smallest increase occurred for small intestine NETs. There were gender and racial differences, which differed site by site and, in some cases, changed over time. The incidence rates (IRs) of GEP-NETs have increased significantly in the last 40 years. Data are only available from North America, Western Europe and Japan. A site-by-site analysis revealed that the IRs of some NETs increased more than those of others.

Neuroendocrine tumors of the bronchopulmonary system (typical and atypical carcinoid tumors): current strategies in diagnosis and treatment. Conclusions of an expert meeting February 2011 in Weimar, Germany

Neuroendocrine tumors (NETs; syn. carcinoid tumors) are highly or moderately differentiated neoplasms. They comprise a large variety of rare and heterogeneous tumors with an estimated incidence of 3-5/100,000/year. They can arise in virtually every internal organ, but mainly occur in the gastroenteropancreatic and bronchopulmonary systems. Around 25% of the NETs are localized in the bronchopulmonary system. Approximately 2% of all lung tumors are NETs. According to the World Health Organization (WHO) classification of lung tumors, bronchopulmonary NETs are subdivided into typical carcinoids (TCs) and atypical carcinoids (ACs). The parameter with the highest impact on NET behavior and prognosis is the histological classification and staging according to the tumor/node/metastasis (TNM) system. The diagnosis of NETs is established by histological examination and the immunohistochemical detection of general neuroendocrine markers, such as chromogranin A (CgA) and synaptophysin. Serum markers and the use of functional imaging techniques are important additive tools to establish the diagnosis of a NET. The only curative option for lung NETs is complete surgical resection. Beyond that, the currently available interdisciplinary therapeutic options are local ablation, biotherapy (somatostatin analogues), or chemotherapy. New therapeutic options such as peptide receptor radionuclide therapy (PRRT) and molecularly targeted therapies achieve promising results and are under further evaluation. This report is a consensus summary of the interdisciplinary symposium 'Neuroendocrine Tumors of the Lung and of the Gastroenteropancreatic System (GEP NET) - Expert Dialogue' held on February 25-26, 2011 in Weimar, Germany. At this conference, a panel of 23 German experts shared their knowledge and exchanged their thoughts about research, diagnosis, and clinical management of NETs, whereby special attention was paid to NETs of the respiratory tract.

Multiple endocrine neoplasia (MEN) syndromes

Multiple endocrine neoplasia (MEN) syndromes are characterised by the combined occurrence of two or more endocrine tumours in a patient. These autosomal dominant conditions occur in four types: MEN1 due to inactivating MEN1 mutations; MEN2A and MEN2B (MEN3) due to activating mutations of RET and MEN4 due to inactivating cyclin-dependent kinase inhibitor 1B (CDKN1B) mutations. Each MEN syndrome exhibits different combinations of pancreatic islet, anterior pituitary, parathyroid, medullary thyroid and adrenal tumours. This article provides an overview of the clinical features, treatments and molecular genetics of each endocrine tumour syndrome.

A single institution's 26-year experience with nonfunctional pancreatic neuroendocrine tumors: a validation of current staging systems and a new prognostic nomogram

OBJECTIVE

To validate the 2010 American Joint Committee on Cancer (AJCC) and 2006 European Neuroendocrine Tumor Society (ENETS) tumor staging systems for pancreatic neuroendocrine tumors (PanNETs) using the largest, single-institution series of surgically resected patients in the literature.

BACKGROUND

The natural history and prognosis of PanNETs have been poorly defined because of the rarity and heterogeneity of these neoplasms. Currently, there are 2 main staging systems for PanNETs, which can complicate comparisons of reports in the literature and thereby hinder progress against this disease.

METHODS

Univariate and multivariate analyses were conducted on the prognostic factors of survival using 326 sporadic, nonfunctional, surgically resected PanNET patients who were cared for at our institution between 1984 and 2011. Current and proposed models were tested for survival prognostication validity as measured by discrimination (Harrel's c-index, HCI) and calibration.

RESULTS

Five-year overall-survival rates for AJCC stages I, II, and IV are 93% (88%-99%), 74% (65%-83%), and 56% (42%-73%), respectively, whereas ENETS stages I, II, III, and IV are 97% (92%-100%), 87% (80%-95%), 73% (63%-84%), and 56% (42%-73%), respectively. Each model has an HCI of 0.68, and they are no different in their ability to predict survival. We developed a simple prognostic tool just using grade, as measured by continuous Ki-67 labeling, sex, and binary age that has an HCI of 0.74.

CONCLUSIONS

Both the AJCC and ENETS staging systems are valid and indistinguishable in their survival prognostication. A new, simpler prognostic tool can be used to predict survival and decrease interinstitutional mistakes and uncertainties regarding these neoplasms.

New model for gastroenteropancreatic large-cell neuroendocrine carcinoma: establishment of two clinically relevant cell lines

Recently, a novel WHO-classification has been introduced that divided gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) according to their proliferation index into G1- or G2-neuroendocrine tumors (NET) and poorly differentiated small-cell or large-cell G3-neuroendocrine carcinomas (NEC). Our knowledge on primary NECs of the GEP-system is limited due to the rarity of these tumors and chemotherapeutic concepts of highly aggressive NEC do not provide convincing results. The aim of this study was to establish a reliable cell line model for NEC that could be helpful in identifying novel druggable molecular targets. Cell lines were established from liver (NEC-DUE1) or lymph node metastases (NEC-DUE2) from large cell NECs of the gastroesophageal junction and the large intestine, respectively. Morphological characteristics and expression of neuroendocrine markers were extensively analyzed. Chromosomal aberrations were mapped by array comparative genomic hybridization and DNA profiling was analyzed by DNA fingerprinting. In vitro and in vivo tumorigenicity was evaluated and the sensitivity against chemotherapeutic agents assessed. Both cell lines exhibited typical morphological and molecular features of large cell NEC. In vitro and in vivo experiments demonstrated that both cell lines retained their malignant properties. Whereas NEC-DUE1 and -DUE2 were resistant to chemotherapeutic drugs such as cisplatin, etoposide and oxaliplatin, a high sensitivity to 5-fluorouracil was observed for the NEC-DUE1 cell line. Taken together, we established and characterized the first GEP large-cell NEC cell lines that might serve as a helpful tool not only to understand the biology of these tumors, but also to establish novel targeted therapies in a preclinical setup.

Endogenous hyperinsulinemic hypoglycemia syndrome: surgical treatment

BACKGROUND

The endogenous hyperinsulinemic hypoglicemia syndrome (EHHS) can be caused by an insulinoma, or less frequently, by nesidioblastosis in the pediatric population, also known as non insulinoma pancreatic hypoglycemic syndrome (NIPHS) in adults. The aim of this paper is to show the strategy for the surgical treatment of ehhs.

MATERIAL AND METHODS

A total of 19 patients with a final diagnosis of insulinoma or NIPHS who were treated surgically from january 2007 until june 2012 were included. We describe the clinical presentation and preoperative work-up. Emphasis is placed on the surgical technique, complications and long-term follow-up.

RESULTS

All patients had a positive fasting plasma glucose test. Preoperative localization of the lesions was possible in 89.4% of cases. The most frequent surgery was distal pancreatectomy with spleen preservation (9 cases). Three patients with insulinoma presented with synchronous metastases, which were treated with simultaneous surgery. There was no perioperative mortality and morbidity was 52.6%. Histological analysis revealed that 13 patients (68.4%) had benign insulinoma, 3 malignant insulinoma with liver metastases and 3 with a final diagnosis of SHPNI. Median follow-up was 20 months. All patients diagnosed with benign insulinoma or NIPHS had symptom resolution.

CONCLUSION

The surgical treatment of EHHS achieves excellent long-term results in the control of hypoglucemic symptoms.

Grading of neuroendocrine neoplasms: mitoses and Ki-67 are both essential

BACKGROUND

The current WHO classification for neuroendocrine neoplasms (NEN) of the gastrointestinal tract requires Ki-67 and mitotic index for grading. However, both indexes might be conflicting as far as grade is concerned. In this study, we investigate which of the two indexes is most informative to predict survival.

METHODS

We assessed 362 patients with NEN of gastrointestinal (n = 148), pancreatic (n = 29), lung (n = 77), unknown primary site (n = 102) and of miscellaneous (n = 6) origin. Follow-up and proliferative indexes were recorded.

RESULTS

Survival was clearly correlated with both proliferative indexes (p < 0.001). One hundred and nineteen samples (34%) showed discordance in grading between the Ki-67 and the mitotic index, of which 74 (62%) were biopsies and 45 (38%) resection specimens (p = 0.001). In 86% of these cases, survival matched with the highest proliferative index, which was the Ki-67 index in 87% of these cases. Seventeen cases had a mitotic index of 2 (threshold grade 2) and a Ki-67 index of <3% (grade 1). For these cases, survival curve matched that of patients with concordant indexes of grade 1.

CONCLUSION

Grading NEN using two proliferative markers results in discordance between these indexes in one third of cases, more often in biopsy material than in resection specimens. If results are discordant, survival is for the most part associated with the grade of the highest index, for the most part Ki-67. Thus, grading with two proliferative indexes is useful as it highlights cases where one of these indexes may be incongruent.

Reliability of proliferation assessment by Ki-67 expression in neuroendocrine neoplasms: eyeballing or image analysis?

BACKGROUND

The latest WHO classification for neuroendocrine neoplasms (NEN) of the gastrointestinal tract defines grade according to Ki-67 and mitotic indices. Some have questioned the reproducibility and thus the reliability of Ki-67 assessment. We therefore investigated the accuracy of this proliferation marker in NEN.

METHODS

The Ki-67 index of tumor specimens of NEN (n = 73) was assessed by two pathologists as in routine practice with eyeballing and twice by image analysis using ImageJ freeware at different magnifications. RESULTS were correlated with overall survival.

RESULTS

The intraclass correlation coefficient (ICC) between pathologists was 0.88. The ICC for the measurements using image analysis was 0.85. The ICC between all four measurements (pathologists and ImageJ) was 0.80. If the Ki-67 index was translated to grade as prescribed by the current WHO classification (<3% = grade 1, 3-20% = grade 2, >20% = grade 3), kappa was between 0.61 and 0.75. Grades based on pathologist scoring were often (16-29%) higher than grades assigned by image analysis (p < 0.001). Grade was significantly correlated with survival (p < 0.0001) irrespective of the way Ki-67 was assessed.

CONCLUSION

Assessment of the Ki-67 index by eyeballing correlates remarkably well with the Ki-67 index as calculated by image analysis and is therefore an accurate parameter. Moreover, it is significantly related to survival irrespective of the method used. Yet if the Ki-67 index is translated to grade, the grade should be interpreted with caution due to values around threshold levels.

Identification of candidate serum proteins for classifying well-differentiated small intestinal neuroendocrine tumors

BACKGROUND

Patients with well-differentiated small intestine neuroendocrine tumors (WD-SI-NETs) are most often diagnosed at a metastatic stage of disease, which reduces possibilities for a curative treatment. Thus new approaches for earlier detection and improved monitoring of the disease are required.

MATERIALS AND METHODS

Suspension bead arrays targeting 124 unique proteins with antibodies from the Human Protein Atlas were used to profile biotinylated serum samples. Discoveries from a cohort of 77 individuals were followed up in a cohort of 132 individuals both including healthy controls as well as patients with untreated primary WD-SI-NETs, lymph node metastases and liver metastases.

RESULTS

A set of 20 antibodies suggested promising proteins for further verification based on technically verified statistical significance. Proceeding, we assessed the classification performance in an independent cohort of patient serum, achieving, classification accuracy of up to 85% with different subsets of antibodies in respective pairwise group comparisons. The protein profiles of nine targets, namely IGFBP2, IGF1, SHKBP1, ETS1, IL1α, STX2, MAML3, EGR3 and XIAP were verified as significant contributors to tumor classification.

CONCLUSIONS

We propose new potential protein biomarker candidates for classifying WD-SI-NETs at different stage of disease. Further evaluation of these proteins in larger sample sets and with alternative approaches is needed in order to further improve our understanding of their functional relation to WD-SI-NETs and their eventual use in diagnostics.

Update on the management of gastroenteropancreatic neuroendocrine tumors with emphasis on the role of imaging

OBJECTIVE

The purposes of this article are to review the current management of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) based on the 2012 National Comprehensive Cancer Network guidelines and to describe the role of imaging in a multidisciplinary approach.

CONCLUSION

The management of GEP-NETs has become complex, requiring a multidisciplinary approach. The World Health Organization classification of GEP-NETs has been revised; the U.S. Food and Drug Administration has approved molecular targeted agents (sunitinib, everolimus) for the treatment of pancreatic NETs; and the National Comprehensive Cancer Network clinical practice guidelines have been updated.

Copy number alterations in small intestinal neuroendocrine tumors determined by array comparative genomic hybridization

Background

Small intestinal neuroendocrine tumors (SI-NETs) are typically slow-growing tumors that have metastasized already at the time of diagnosis. The purpose of the present study was to further refine and define regions of recurrent copy number (CN) alterations (CNA) in SI-NETs.

Methods

Genome-wide CNAs was determined by applying array CGH (a-CGH) on SI-NETs including 18 primary tumors and 12 metastases. Quantitative PCR analysis (qPCR) was used to confirm CNAs detected by a-CGH as well as to detect CNAs in an extended panel of SI-NETs. Unsupervised hierarchical clustering was used to detect tumor groups with similar patterns of chromosomal alterations based on recurrent regions of CN loss or gain. The log rank test was used to calculate overall survival. Mann–Whitney U test or Fisher’s exact test were used to evaluate associations between tumor groups and recurrent CNAs or clinical parameters.

Results

The most frequent abnormality was loss of chromosome 18 observed in 70% of the cases. CN losses were also frequently found of chromosomes 11 (23%), 16 (20%), and 9 (20%), with regions of recurrent CN loss identified in 11q23.1-qter, 16q12.2-qter, 9pter-p13.2 and 9p13.1-11.2. Gains were most frequently detected in chromosomes 14 (43%), 20 (37%), 4 (27%), and 5 (23%) with recurrent regions of CN gain located to 14q11.2, 14q32.2-32.31, 20pter-p11.21, 20q11.1-11.21, 20q12-qter, 4 and 5. qPCR analysis confirmed most CNAs detected by a-CGH as well as revealed CNAs in an extended panel of SI-NETs. Unsupervised hierarchical clustering of recurrent regions of CNAs revealed two separate tumor groups and 5 chromosomal clusters. Loss of chromosomes 18, 16 and 11 and again of chromosome 20 were found in both tumor groups. Tumor group II was enriched for alterations in chromosome cluster-d, including gain of chromosomes 4, 5, 7, 14 and gain of 20 in chromosome cluster-b. Gain in 20pter-p11.21 was associated with short survival. Statistically significant differences were observed between primary tumors and metastases for loss of 16q and gain of 7.

Conclusion

Our results revealed recurrent CNAs in several candidate regions with a potential role in SI-NET development. Distinct genetic alterations and pathways are involved in tumorigenesis of SI-NETs.

Gene Expression of Glucose Transporter 1 (GLUT1), Hexokinase 1 and Hexokinase 2 in Gastroenteropancreatic Neuroendocrine Tumors: Correlation with F-18-fluorodeoxyglucose Positron Emission Tomography and Cellular Proliferation

Neoplastic tissue exhibits high glucose utilization and over-expression of glucose transporters (GLUTs) and hexokinases (HKs), which can be imaged by ¹⁸F-Fluorodeoxyglucose-positron emission tomography (FDG-PET). The aim of the present study was to investigate the expression of glycolysis-associated genes and to compare this with FDG-PET imaging as well as with the cellular proliferation index in two cancer entities with different malignant potential. Using real-time PCR, gene expression of GLUT1, HK1 and HK2 were studied in 34 neuroendocrine tumors (NETs) in comparison with 14 colorectal adenocarcinomas (CRAs). The Ki67 proliferation index and, when available, FDG-PET imaging was compared with gene expression. Overexpression of GLUT1 gene expression was less frequent in NETs (38%) compared to CRAs (86%), P = 0.004. HK1 was overexpressed in 41% and 71% of NETs and CRAs, respectively (P = 0.111) and HK2 was overexpressed in 50% and 64% of NETs and CRAs, respectively (P = 0.53). There was a significant correlation between the Ki67 proliferation index and GLUT1 gene expression for the NETs (R = 0.34, P = 0.047), but no correlation with the hexokinases. FDG-PET identified foci in significantly fewer NETs (36%) than CRAs (86%), (P = 0.04). The gene expression results, with less frequent GLUT1 and HK1 upregulation in NETs, confirmed the lower metabolic activity of NETs compared to the more aggressive CRAs. In accordance with this, fewer NETs were FDG-PET positive compared to CRA tumors and FDG uptake correlated with GLUT1 gene expression.

Recurrence of a carcinoid tumor of the ovary 13 years after the primary surgery: A case report

The current study presents the case of a patient with a recurrent carcinoid tumor of the ovary, 13-years after the primary surgery. The primary surgery consisted of a total abdominal hysterectomy and bilateral salpingo-oophorectomy for a left ovarian tumor at 54 years old. Pathologically, the tumor was diagnosed as a carcinoid tumor of the ovary. Following the primary treatment, the patient was admitted to a cardiologist due to carcinoid-induced heart failure. At 67 years old, the patient was referred to Kyoto University Hospital with a solitary mass 8 cm in diameter and located in the paraaortic area, which was detected by routine ultrasonography and subsequent computed tomography (CT) scans. Urinary 5-hydroxyindole acetate (5-HIAA), a serotonin degradation metabolite, was present at elevated levels. With a diagnosis of a recurrent carcinoid tumor, the patient underwent a tumor resection. The pathological diagnosis was that of lymph node metastasis of the trabecular carcinoid. Post-operatively, the 5-HIAA levels returned to normal. Carcinoid tumors occasionally recur following surgery due to borderline malignant potential. Due to the slow growing nature of these tumors, in specific cases, recurrence occurs following a long interval. Therefore, a relatively long follow-up period is required.

Proposal for a standardized pathology report of gastroenteropancreatic neuroendocrine tumors: prognostic significance of pathological parameters

Background

There is confusion in the diagnosis and biological behaviors of gastroenteropancreatic neuroendocrine tumors (GEP-NETs), because of independently proposed nomenclatures and classifications. A standardized form of pathology report is required for the proper management of patients.

Methods

We discussed the proper pathological evaluation of GEP-NET at the consensus conference of the subcommittee meeting for the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. We then verified the prognostic significance of pathological parameters from our previous nationwide collection of pathological data from 28 hospitals in Korea to determine the essential data set for a pathology report.

Results

Histological classification, grading (mitosis and/or Ki-67 labeling index), T staging (extent, size), lymph node metastasis, and lymphovascular and perineural invasion were significant prognostic factors and essential for the pathology report of GEP-NET, while immunostaining such as synaptophysin and chromogranin may be optional. Furthermore, the staging system, either that of the 2010 American Joint Cancer Committee (AJCC) or the European Neuroendocrine Tumor Society (ENETS), should be specified, especially for pancreatic neuroendocrine neoplasms.

Conclusions

A standardized pathology report is crucial for the proper management and prediction of prognosis of patients with GEP-NET.

Guidelines for biomarker testing in gastroenteropancreatic neuroendocrine neoplasms: a national consensus of the Spanish Society of Pathology and the Spanish Society of Medical Oncology

The annual incidence of neuroendocrine tumours in the Caucasian population ranges from 2.5 to 5 new cases per 100,000 inhabitants. Gastroenteropancreatic neuroendocrine tumours is a family of neoplasms widely variable in terms of anatomical location, hormone composition, clinical syndromes they cause and in their biological behaviour. This high complexity and clinical heterogeneity, together with the known difficulty of predicting their behaviour from their pathological features, are reflected in the many classifications that have been developed over the years in this field. This article reviews the main tissue and clinical biomarkers and makes recommendations for their use in medical practice. This document represents a consensus reached jointly by the Spanish Society of Medical Oncology (SEOM) and the Spanish Society of Pathology (SEAP).

Characterization of neuroendocrine tumors of the pancreas by real-time quantitative polymerase chain reaction. A methodological approach

The aim of this study was to assess the suitability of using real-time quantitative PCR (RT-qPCR) to characterize neuroendocrine (NE) tumors of the pancreas. For a series of tumors, we evaluated several genes of interest, and the data were matched with the "classical" immunohistochemical (IHC) features. In 21 cases, we extracted RNA from formalin-fixed paraffin-embedded (FFPE) blocks, and in nine cases, we also extracted RNA from fresh-frozen tissue. The RT-qPCR procedure was performed using two sets of customized arrays. The test using the first set, covering 96 genes of interest, was focused on assessing the feasibility of the procedure, and the results were used to select 18 genes indicative of NE differentiation, clinical behavior, and therapeutic responsiveness for use in the second set of arrays. Threshold cycle (Ct) values were used to calculate the fold-changes in gene expression using the 2-∆∆Ct method. Statistical procedures were used to analyze the results, which were matched with the IHC and follow-up data. Material from fresh-frozen samples performed better in terms of the level of amplification, but acceptable and concordant results were also obtained from FFPE samples. In addition, high concordance was observed between the mRNA and protein expression levels of somatostatin receptor type 2A (R = 0.52, p = 0.016). Genes associated with NE differentiation, as well as the gastrin-releasing peptide receptor and O-6-methylguanine-DNA methyltransferase genes, were underexpressed, whereas angiogenesis-associated markers (CDH13 and SLIT2) were overexpressed in tissues with malignant behavior. The RT-qPCR procedure is practical and feasible in economic terms for the characterization of NE tumors of the pancreas and can complement morphological and IHC-based evaluations. Thus, the results of the RT-qPCR procedure might offer an objective basis for therapeutic choices.

Clinical validation of the gastrointestinal NET grading system: Ki67 index criteria of the WHO 2010 classification is appropriate to predict metastasis or recurrence

BACKGROUND

In the WHO 2010 classification, the neuroendocrine tumors (NETs) are subdivided by their mitotic index or Ki67 index into either G1 or G2 NETs. Tumors with a Ki67 index of <2% are classified as G1 and those with 3-20% are classified as G2. However, the assessment of tumors with Ki67 index of greater than 2% and less than or equal to 3% is still unclear. To resolve the problem, we validated the Ki67 index criteria of gastrointestinal NETs of the WHO 2010 classification.

METHODS

The medical records of 45 patients who were pathologically diagnosed as having NET G1/G2 of the gastrointestinal tract were analyzed retrospectively. According to the WHO 2010 classification, Ki67 index were calculated. Computer-assisted cytometrical analysis of Ki67 immunoreactivity was performed using the WinRooF image processing software. Receiver operating characteristic (ROC) curves were generated to determine the best discriminating Ki67 index. To clarify the assessment of tumors with Ki67 index between 2-3%, the calculated cutoff of Ki67 index was evaluated using Fisher's exact test.

RESULTS

ROC curve analysis confirmed that 2.8% was the best Ki67 index cutoff value for predicting metastasis or recurrence. The sensitivity of the new Ki67 index cutoff was 42.9%, and the specificity was 86.8%.

CONCLUSIONS

Division of NETs into G1/G2 based on Ki67 index of 3% was appropriate to predict metastases or recurrences. The WHO grading system may be the most useful classification to predict metastases or recurrences.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1553036118943799.