Multicenter retrospective analysis of systemic chemotherapy for advanced neuroendocrine carcinoma of the digestive system

Systematic review of case reports of Japanese esophageal neuroendocrine cell carcinoma in the Japanese literature

Esophageal neuroendocrine cell carcinoma (NEC) is extremely rare, and its treatment strategy has not been established. Systematic review and meta-analysis were carried out to assess the treatment and prognosis of patients with esophageal NEC in Japan. The Ichushi-Web database was searched from January 1964 to May 2018. In total, 141 cases of esophageal NEC were included in the analysis. The survival of the chemotherapy group with stage II/III esophageal NEC was better than that of the surgery group. Meanwhile, the survival of the adjuvant treatment group with stage II/III esophageal NEC was significantly better than that of the surgery alone group. In patients with stage IV esophageal NEC, no significant differences were observed in terms of treatment response from the three regimens: irinotecan/platinum and etoposide/platinum compared with 5-fluorouracil/platinum. Moreover, no significant differences were observed in the survival of patients who received the chemotherapy regimens. However, the 2-year survival rates of the irinotecan/platinum (26%) group and etoposide/platinum (27%) group were higher than that of the 5-fluorouracil/platinum (0%) group. In esophageal NEC, chemotherapy may be used as the first-line treatment. Irinotecan/platinum or etoposide/platinum can be the first-line regimen for chemotherapy. However, the additive effects of surgery remain unclear.

Development and characterization of a cancer cachexia model employing a rare human duodenal neuroendocrine carcinoma-originating cell line

Cancer cachexia interferes with therapy and worsens patients' quality of life. Therefore, for a better understanding of cachexia, we aimed to establish a reliable cell line to develop a cachexia model. We recently established and characterized the TCC-NECT-2 cell line, derived from a Japanese patient with poorly differentiated neuroendocrine carcinoma of the duodenum (D-NEC). Subcutaneous xenograft of TCC-NECT-2 cells in mice resulted in tumor formation, angiogenesis, and 20% incidence of body weight (BW)-loss. Subsequently, we isolated a potent cachexia-inducing subline using stepwise selection and designated as AkuNEC. Orthotopic and s.c. implantation of AkuNEC cells into mice led to diminished BW, anorexia, skeletal muscle atrophy, adipose tissue loss, and decreased locomotor activity at 100% incidence. Additionally, orthotopic implantation of AkuNEC cells resulted in metastasis and angiogenesis. Serum IL-8 overproduction was observed, and levels were positively correlated with BW-loss and reduced adipose tissue and muscle volumes in tumor-bearing mice. However, shRNA knockdown of the IL-8 gene did not suppress tumor growth and cachexia in the AkuNEC model, indicating that IL-8 is not directly involved in cachexia induction. In conclusion, AkuNEC cells may serve as a useful model to study cachexia and D-NEC.

Long-term control with chemoradiation of initially metastatic mixed adenoneuroendocrine carcinoma of the rectum: a case report

BACKGROUND

Mixed adenoneuroendocrine carcinomas are highly malignant tumors with both adenocarcinomatous and neuroendocrine components. They can originate in any organ but are more common in the rectum. Due to their rarity, current treatment recommendations for mixed adenoneuroendocrine carcinoma are based on limited data and follow general guidelines for the management of adenocarcinomas and neuroendocrine neoplasms. Uncertainty regarding the efficacy of the available local and systemic treatment strategies is a compounding issue. Even those patients with locally limited disease have a relatively short life expectancy. In this report, we describe a case of deep rectal mixed adenoneuroendocrine carcinoma with long survival after chemoradiation.

CASE PRESENTATION

A 48-year-old Caucasian woman was diagnosed with a grade 3 rectal adenocarcinoma combined with a poorly differentiated large cell neuroendocrine carcinoma component and synchronous metastases (cT3cN1cM1) in both lobes of the liver in 2012. She received concomitant chemoradiotherapy followed by four additional cycles of cisplatin plus irinotecan. Initial treatment induced complete remission of the rectal tumor and liver metastases. Consequently, it was not necessary to surgically resect the primary tumor or any of the metastases. Three months after the end of treatment, one metastasis in the first segment of the liver showed regrowth, and stereotactic body radiotherapy of the metastasis and chemotherapy resulted in a clinical complete response. The patient has been recurrence-free for more than 5 years.

CONCLUSIONS

Extended long-term control of a poorly differentiated metastatic (stage IV) mixed adenoneuroendocrine carcinoma is rare. The multimodal first- and second-line regimens of radiotherapy and chemotherapy described in this case report represent a new therapeutic approach. Encouraged by the results in this case, we compiled a review of the literature on mixed adenoneuroendocrine carcinoma.

A rare rarity: Neuroendocrine tumor of the esophagus

Esophageal Neuroendocrine tumors (NETs) are rare, aggressive and lacking specific symptoms. This causes a diagnostic delay, worsening the prognosis. Numerous cases are reported in literature, without a consensus on the management. Our aim was to clarify epidemiology, clinical presentation, diagnostic, therapeutic management of esophageal NETs. Extensive literature search identified a total of 226 articles. One hundred twenty-five articles (n = 1676) met the inclusion criteria, showing that: the incidence of esophageal NET varies geographically; men (60-70 years) are more affected; smoking and alcohol abuse are the major risk factors; dysphagia, weight loss, appetite loss are the most common clinical features. The histotypes include high-grade small and large cell esophageal carcinomas and low-grade carcinoid tumors. Mixed neuroendocrine/non-neuroendocrine neoplasms are the most common. Often the diagnosis occurs randomly on endoscopic examination. Circulating markers, functional combined with conventional imaging contributes to the diagnosis and management. Treatment depends on type, grade and stage of the tumor.

Peptide receptor radionuclide therapy in gastroenteropancreatic NEN G3: a multicenter cohort study

Peptide receptor radionuclide therapy (PRRT) is an established treatment of metastatic neuroendocrine tumors grade 1-2 (G1-G2). However, its possible benefit in high-grade gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN G3) is largely unknown. We therefore aimed to assess the benefits and side effects of PRRT in patients with GEP NEN G3. We performed a retrospective cohort study at 12 centers to assess the efficacy and toxicity of PRRT in patients with GEP NEN G3. Outcomes were response rate, disease control rate, progression-free survival (PFS), overall survival (OS) and toxicity. We included 149 patients (primary tumor: pancreatic n = 89, gastrointestinal n = 34, unknown n = 26). PRRT was first-line (n = 30), second-line (n = 62) or later-line treatment (n = 57). Of 114 patients evaluated, 1% had complete response, 41% partial response, 38% stable disease and 20% progressive disease. Of 104 patients with documented progressive disease before PRRT, disease control rate was 69%. The total cohort had median PFS of 14 months and OS of 29 months. Ki-67 21-54% (n = 125) vs Ki-67 ≥55% (n = 23): PFS 16 vs 6 months (P < 0.001) and OS 31 vs 9 months (P < 0.001). Well (n = 60) vs poorly differentiated NEN (n = 62): PFS 19 vs 8 months (P < 0.001) and OS 44 vs 19 months (P < 0.001). Grade 3-4 hematological or renal toxicity occurred in 17% of patients. This large multicenter cohort of patients with GEP NEN G3 treated with PRRT demonstrates promising response rates, disease control rates, PFS and OS as well as toxicity in patients with mainly progressive disease. Based on these results, PRRT may be considered for patients with GEP NEN G3.

Survival in Patients with High-Grade Colorectal Neuroendocrine Carcinomas: The Role of Surgery and Chemotherapy

BACKGROUND

Colorectal neuroendocrine tumors are a rare malignancy, yet their incidence appears to be increasing. The optimal treatment for the high-grade subset of these tumors remains unclear. We aimed to examine the relationship between different treatment modalities and outcomes for patients with high-grade neuroendocrine carcinomas (HGNECs) of the colon and rectum.

METHODS

The National Cancer Database (2004-2015) was used to identify patients diagnosed with colorectal HGNECs. The primary outcome was overall survival. A Cox Proportional hazard model was used to identify risk factors for survival.

RESULTS

Overall, 1208 patients had HGNECs; 452 (37.4%) patients had primary tumors of the rectum, and 756 (62.5%) patients had primary tumors of the colon. A total of 564 (46.7%) patients presented with stage IV disease. The median survival was 9.0 months [95% confidence interval (CI) 8.2-9.8]. In multivariable analysis, surgical resection [hazard ratio (HR) 0.54, 95% CI 0.44-0.66; p < 0.001], chemotherapy (HR 0.74, 95% CI 0.69-0.79; p < 0.001), and rectum as the primary site of tumor (HR 0.62, 95% CI 0.51-0.76; p < 0.001) were associated with better overall survival, while older age (HR 1.01, 95% CI 1.00-1.01; p = 0.02) and the presence of metastatic disease (HR 3.34, 95% CI 2.69-4.15; p < 0.001) were associated with worse survival.

CONCLUSIONS

Patients with colorectal HGNECs selected for chemotherapy and surgical resection of the primary tumor demonstrated better overall survival than those managed without resection. Patients who were able to undergo systemic chemotherapy may benefit from potentially curative resection of the primary tumor.

Current Treatment Options in Gastroenteropancreatic Neuroendocrine Carcinoma

Poorly differentiated gastroenteropancreatic neuroendocrine carcinomas (GEPNECs) are a rare neoplasm with a bleak prognosis. Currently there are little prospective data available for optimal treatment. This review discusses the current available regimens and the future direction for the treatment of GEPNECs. Treatment plans for GEPNECs are often adapted from those devised for small cell lung cancer; however, differences in these malignancies exist, and GEPNECs require their own treatment paradigms. As such, current first-line treatment for GEPNECs is platinum-based chemotherapy with etoposide. Studies show that response rate and overall survival remain comparable between cisplatin and carboplatin versus etoposide and irinotecan; however, prognosis remains poor, and more efficacious therapy is needed to treat this malignancy. Additional first-line and second-line treatment options beyond platinum-based chemotherapy have also been investigated and may offer further treatment options, but again with suboptimal outcomes. Recent U.S. Food and Drug Administration approval of peptide receptor radionuclide therapy in low- and intermediate-grade neuroendocrine tumors may open the door for further research in its usefulness in GEPNECs. Additionally, the availability of checkpoint inhibitors lends promise to the treatment of GEPNECs. This review highlights the lack of large, prospective studies that focus on the treatment of GEPNECs. There is a need for randomized control trials to elucidate optimal treatment regimens specific to this malignancy. IMPLICATIONS FOR PRACTICE: There are limited data available for the treatment of poorly differentiated gastroenteropancreatic neuroendocrine carcinomas (GEPNECs) because of the rarity of this malignancy. Much of the treatment regimens used in practice today come from research in small cell lung cancer. Given the poor prognosis of GEPNECs, it is necessary to have treatment paradigms specific to this malignancy. The aim of this literature review is to summarize the available first- and second-line GEPNEC therapy, outline future treatments, and highlight the vast gap in the literature.

Carboplatin in Combination with Oral or Intravenous Etoposide for Extra-Pulmonary, Poorly-Differentiated Neuroendocrine Carcinomas

BACKGROUND

Carboplatin-etoposide (CarboEtop) is a 1st-line option for patients with advanced extra-pulmonary (EP), poorly-differentiated (PD) neuroendocrine carcinoma (NEC). Different schedules are used in clinical practice and randomised evidence is lacking.

OBJECTIVES

To provide real-life outcomes of carboplatin combined with oral or intravenous (IV) etoposide (Etop) in advanced EP-PD-NEC, from 2 specialist centres.

METHODS

Activity/efficacy/toxicity data of CarboEtop were collected retrospectively and analysed.

RESULTS

We identified 113 patients; median age: 65.8 years; male: 64%; gastro-entero-pancreatic origin: 54%; stage IV: 90%; median Ki-67: 70%; median follow-up: 11.5 months. A total of 123 courses of CarboEtop (oral: 45%; IV: 55%) were administered; 106 (86%) 1st-line, 16 (13%) 2nd-line, and 1 (1%) 3rd-line. Disease control rate: 74.5% in 1st-line and 69.2% in 2nd/3rd-line, with no significant difference between oral and IV Etop in 1st-line (69.8 vs. 80.8%, p = 0.237). Median progression-free survival (PFS): 6.0 and 4.5 months in 1st-line and 2nd/3rd-line, respectively. Overall survival (OS): 11.5 and 12.5 months in 1st-line and 2nd/3rd-line, respectively. The schedule (oral versus IV Etop) did not impact on 1st-line PFS (5.6 vs. 6.2 months, p = 0.179), although there was a trend towards shorter OS (8.9 vs. 12.1 months, p = 0.069). Liver metastases correlated with worse 1st-line PFS (p = 0.015) and 1st-line OS (p < 0.001) on multivariable analysis. The commonest grade 3-4 adverse event was myelosuppression (49%), with comparable toxicity between oral and IV Etop, except for venous thromboembolism (12.5 vs. 1.7%, p = 0.04).

CONCLUSIONS

CarboEtop for advanced EP-PD-NEC is active, effective, and well-tolerated. Oral and IV Etop schedules are associated with comparable toxicity; activity should be compared in larger cohorts.

The Molecular and Clinical Landscape of Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors are rare tumors of the pancreas originating from the islets of the Langerhans. These tumors comprise 1% to 3% of all newly diagnosed pancreatic cancers every year and have a unique heterogeneity in clinical presentation. Whole-genome sequencing has led to an increased understanding of the molecular biology of these tumors. In this review, we will summarize the current knowledge of the signaling pathways involved in the tumorigenesis of pancreatic neuroendocrine tumors as well as the major studies targeting these pathways at preclinical and clinical levels.

Efficacy and safety of ramucirumab-containing chemotherapy in patients with pretreated metastatic gastric neuroendocrine carcinoma

BACKGROUND

Ramucirumab (RAM), a monoclonal antibody for vascular endothelial growth factor 2 (VEGFR2), has been effective for advanced gastric adenocarcinoma (AC). However, little is known about the efficacy of RAM-containing chemotherapy (RAM-CTx) in gastric neuroendocrine carcinoma (G-NEC).

METHODS

We retrospectively analysed and compared the clinical outcomes of patients (pts) with G-NEC receiving RAM-CTx, G-NEC receiving CTx without RAM and AC receiving RAM-CTx in our hospital. G-NEC was defined by neuroendocrine carcinoma features, regardless of the proportion, based on histology and neuroendocrine markers (synaptophysin, chromogranin A or CD56). VEGFR2 expression in tumour vessels was evaluated in archival primary G-NEC tissues by immunohistochemistry using the same anti-VEGFR2 primary antibody and scoring scheme (vascular VEGFR2 H-score) as in the REGARD trial.

RESULTS

Seventeen G-NEC receiving RAM-CTx, 13 G-NEC receiving CTx without RAM and 173 AC pts receiving RAM-CTx were analysed. The overall response rate (59% vs 8 % vs 28%), progression-free survival (median 7.7 vs 1.8 vs 3.3 months) and overall survival (median 16.1 vs 8.6 vs 9.6 months) were significantly better in pts with G-NEC receiving RAM-CTx than G-NEC receiving CTx without RAM or AC receiving RAM-CTx. No severe or unexpected adverse events occurred. The median vascular VEGFR2 H-score, based on available G-NEC tissues from 12 pts receiving RAM-CTx, was 220 (range 150-260), which was markedly higher than that reported on AC tissues from the REGARD trial as historical control (median 35, range 0-240).

CONCLUSIONS

RAM-CTx showed a promising activity without severe or unexpected safety profile in pts with G-NEC. This may in part be explained by higher vascular VEGFR2 expression in G-NEC tissues.

Analysis of Gastric Carcinoma With Neuroendocrine Character

The clinical significance of gastric adenocarcinoma with neuroendocrine differentiation is unclear because of its rarity. The aim of this study was to suggest a treatment strategy for this tumor. A total of 10 resected gastric tumors with neuroendocrine character, including 3 neuroendocrine carcinomas (NECs) and 7 adenocarcinomas with neuroendocrine differentiation, were retrospectively reviewed regarding tumor characteristics and therapeutic outcomes. The gastric adenocarcinomas with neuroendocrine differentiation had high rates of lymph node metastasis and vessel invasion, and showed the poor prognoses as NEC. The median survival time (MST) was 13 months. Preoperative and postoperative chemotherapy tended to prolong the MST compared with operation alone (112.5 versus 5 months; P = 0.058). Moreover, chemotherapy for postoperative recurrence significantly contributed to improving prognosis (MST, 15 versus 7 months; P = 0.025). Gastric adenocarcinoma with neuroendocrine differentiation had equivalently high potential malignancy as NEC. More aggressive treatment should be considered for this tumor according to NEC.

Metastatic esophageal carcinosarcoma comprising neuroendocrine carcinoma, squamous cell carcinoma, and sarcoma: A case report

RATIONALE

Esophageal carcinosarcoma generally comprises 2 histological components: squamous cell carcinoma (SqCC) and sarcoma. Esophageal carcinosarcoma comprising 3 components is extremely rare and no reports have described therapeutic effects for this disease with metastasis.

PATIENT CONCERNS

A 76-year-old man with dysphagia presented to a local clinic. Gastrointestinal endoscopy revealed a polypoid tumor in the middle esophagus and he was referred to our hospital.

DIAGNOSIS AND INTERVENTIONS

Thoracoscopic esophagectomy with super-extended (D3) nodal dissection and gastric tube reconstitution was performed, which resulted in carcinosarcoma comprising neuroendocrine carcinoma (NEC), SqCC, and sarcoma. Pathological stage was T1bN1M0 stage IIB according to the TNM Classification of Malignant Tumors-7th edition. The NEC component was observed in lymph node. At 47 days after surgery, lymph nodes, liver, and bone metastasis appeared, and tumor markers such as ProGRP and NSE were elevated. Combination chemotherapy with cisplatin and etoposide (EP) adapted to NEC was performed.

OUTCOMES

The patient showed complete response within 4 cycles of chemotherapy. However, the disease recurred 5.5 months after the final course of EP chemotherapy.

LESSONS

A therapeutic strategy based on assessment of which component caused metastasis might be important for metastatic carcinosarcoma comprising 3 components, although more accumulation of data about the efficacy of chemotherapy is necessary. Moreover, elucidation of the mechanisms underlying generation of carcinosarcoma is expected in the future.

Current Chemotherapy Use in Neuroendocrine Tumors

The role of chemotherapy in neuroendocrine tumors (NETs) has evolved with the development of other effective systemic therapies. At the same time, the evolving classification of NETs by grade has allowed for prognostic stratification. Chemotherapy is not routinely used for grade 1 to 2 NETs, but capecitabine (CAPTEM) or streptozocin-based regimens may be used, particularly for pancreatic NETs. In contrast, poorly differentiated grade 3 NETs are usually treated with platinum doublet chemotherapy. There is no consensus for the treatment of well-differentiated G3 NETs, but platinum doublets or CAPTEM are reasonable options.

The Problem of High-Grade Gastroenteropancreatic Neuroendocrine Neoplasms: Well-Differentiated Neuroendocrine Tumors, Neuroendocrine Carcinomas, and Beyond

High-grade gastroenteropancreatic neuroendocrine neoplasms are well-differentiated neuroendocrine tumors or poorly differentiated small/large cell neuroendocrine carcinoma. Distinguishing these entities relies on different genetic backgrounds and resulting different biology. The new classification creates several problems. Almost all clinical treatment data on neuroendocrine neoplasms do not stratify between well and poorly differentiated, providing insufficient help in treatment selection. Treatment of gastroenteropancreatic neuroendocrine neoplasms should separate between well-differentiated neuroendocrine tumors and neuroendocrine carcinoma, and depends on primary tumor site, stage, proliferation rate, and clinical course. This article addresses how to diagnose and treat gastroenteropancreatic neuroendocrine neoplasms, focusing on well-differentiated neuroendocrine tumors versus neuroendocrine carcinomas.

Large Cell Neuroendocrine Carcinoma of the Colon With Carcinomatosis Peritonei

Colorectal large-cell neuroendocrine carcinomas (NECs) are extremely rare and have very poor prognosis compared to adenocarcinomas. A 74-year-old man presented with abdominal pain, diarrhea and hematochezia. The histopathologic report of colonoscopic biopsy performed at a local clinic was a poorly differentiated carcinoma. An abdominopelvic computed scan revealed irregularly enhanced wall thickening at the sigmoid colon with regional fat stranding and lymphnode enlargement. He underwent a laparoscopic high anterior resection with selective peritonectomy for peritoneal carcinomatosis, intraoperative peritoneal irrigation chemotherapy, and early postoperative intraperitoneal chemotherapy for 5 days. The tumor had a high proliferation rate (mitotic count > 50/10 HPFs and 90% of the Ki-67 index) and lymph-node metastases had occurred. On immunohistochemistry, the tumor cells expressed CD56 and synaptophysin. Large-cell NEC was confirmed. Systemic chemotherapy with cisplatin/etoposide was done. The patient is still alive after 3 years with no evidence of recurrence.

Treatment options for PNET liver metastases: a systematic review

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) are rare pancreatic neoplasms. About 40-80% of patients with PNET are metastatic at presentation, usually involving the liver (40-93%). Liver metastasis represents the most significant prognostic factor. The aim of this study is to present an up-to-date review of treatment options for patients with liver metastases from PNETs.

METHODS

A systematic literature search was performed using the PubMed database to identify all pertinent studies published up to May 2018.

RESULTS

The literature search evaluated all the therapeutic options for patients with liver metastases of PNETs, including surgical treatment, loco-regional therapies, and pharmacological treatment. All the different treatment options showed particular indications in different presentations of liver metastases of PNET. Surgery remains the only potentially curative therapeutic option in patients with PNETs and resectable liver metastases, even if relapse rates are high. Efficacy of medical treatment has increased with advances in targeted therapies, such as everolimus and sunitinib, and the introduction of radiolabeled somatostatin analogs. Several techniques for loco-regional control of metastases are available, including chemo- or radioembolization.

CONCLUSIONS

Treatment of patients with PNET metastases should be multidisciplinary and must be personalized according to the features of individual patients and tumors.

Neuroendocrine carcinoma in the extrahepatic biliary tract: A case report and literature review

RATIONALE

Neuroendocrine carcinoma (NEC) arising from the extrahepatic biliary tracts (EHBTs) is rare, and thus its management and prognosis remain poorly clarified. We herein describe a case of NEC in the perihilar EHBTs, and review the literature, together with a comparison between NECs in the perihilar and distal EHBTs, to elucidate the management strategy and oncological outcome of this rare entity.

PATIENT CONCERNS

A 62-year-old Chinese male was admitted with complaints of painless jaundice. Imaging studies revealed a 2-cm mass in the hepatic hilum, regional lymph node involvement, and severe stenosis at the junction of the common hepatic ducts.

DIAGNOSES

The histopathological examination of the resected specimen demonstrated small tumor cells with round hperchromatic nuclei and scant cytoplasm. A detailed immunohistochemical analysis showed that the tumor was strongly positive for synaptophysin, CD56 and chromogranin A, with a Ki-67 labeling index greater than 80%. These results led to a diagnosis of NEC in the perihilar bile duct.

INTERVENTIONS

The patient underwent surgical resection including a left hemihepatectomy, cholecystectomy, lymphadenectomy and Roux-en-Y hepaticojejunostomy.

OUTCOMES

During the two months of follow-up, repeated imaging studies indicated tumor recurrence in the liver. The patient died 6 months after surgery.

LESSONS

NEC in the EHBTs is extremely challenging to diagnose preoperatively because of mimicking other bile duct cancers. The prognosis of this disease entity is dismal, and most patients die within 2 years after diagnosis. Subtyping of NECs into perihilar NECs and distal NECs is beneficial for clinical applications, including guiding therapy selection and predicting survival.

Unusual Sites of High-Grade Neuroendocrine Carcinomas: A Case Series and Review of the Literature

Case series

Patient: Female, 29 • Female, 69 • Female, 52 • Female, 71 • Male, 62 • Female, 67

Final Diagnosis: Neuroendocrine carcinoma

Symptoms: Abdominal pain

Medication: —

Clinical Procedure: —

Specialty: Oncology

Small cell carcinoma of the stomach: A report of two cases and a review of the literature

Primary small cell gastric carcinomas (SCGC) are rare tumors with an aggressive nature, characterized by early, widespread metastases and poor overall prognosis. SCGC shares similar clinicopathological and molecular characteristics with small cell lung carcinoma and is usually treated in a similar manner. Here, two cases of SCGC in young Caucasian male patients are presented. One patient had metastatic and the other locoregional disease. Multimodal treatment was applied in each case; the resulting survival time was 20.2 months in the patient with initially locoregional disease whereas the remains alive and disease-free 20 months after initial diagnosis. A review of the literature is also presented.

Establishment of preclinical chemotherapy models for gastroenteropancreatic neuroendocrine carcinoma

Gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC) is a rare and devastating malignancy, and preclinical studies are needed to evaluate potential therapeutic regimens. Here, we examined the antitumor effects of cisplatin (CDDP), etoposide (ETP) and irinotecan (CPT-11) and their combinations on GEP-NEC using three small-cell GEP-NEC cell lines (pancreatic NEC, A99; esophageal NEC, TYUC-1; duodenum NEC, TCC-NECT-2). In vitro studies were conducted using cell viability assays. In vivo experiments were conducted in mice inoculated with A99 or TCC-NECT-2 and treated with no agent, CDDP, CDDP+ETP (EP) or CDDP+CPT-11 (IP). TYUC-1 was the most susceptible to all agents, whereas A99 was refractory. Classical isobolograms showed synergism in both the EP and IP combinations for the three cell lines. In the TCC-NECT-2 mouse model, the IP regimen showed a significant antitumor effect, and CDDP alone showed a marginal effect compared to the control. In contrast, no effect was detected in the A99 model, probably because A99 was established from a metastatic tumor after chemotherapy with EP. Gene expression analysis of the ATP-binding cassette transporters revealed that ATP binding cassette subfamily B member1 (ABCB1) was conspicuously expressed in A99, and ABCB1 and ATP binding cassette subfamily C member2 (ABCC2) were deficient in TYUC-1, which might explain a part of different CDDP susceptibilities between cell lines. These preclinical models indicate that CDDP is a key agent, and IP regimen might be a reasonable option, although its efficacy is moderate. Our data on the platinum-based regimen will be useful as reference information in developing new agents for GEP-NEC.

Sunitinib shrinks NET-G3 pancreatic neuroendocrine neoplasms

PURPOSE

The 2017 revised World Health Organization classification of pancreatic neuroendocrine neoplasms classified conventional G3 tumors into well-differentiated (NET-G3) and poorly differentiated (NEC-G3) tumors. However, guidelines for selection of drug therapy were not established in the 2017 revision. This study aimed to elucidate the rates of maximum tumor reduction of sunitinib, progression-free survival, and overall survival in the new classification.

METHODS

We investigated the reduction rate over time using computed tomography for 60 patients with unresectable or distant metastatic pancreatic neuroendocrine neoplasms who received 37.5 mg of sunitinib in our department from April 2013 to November 2017.

RESULTS

Of the 60 cases, 42, 10, and 5 were NET-G1/G2, NET-G3, and NEC-G3, respectively. The prognostic factors were analyzed according to clinicopathological factors using the Cox hazard model. The median observation period was 19 months, and the median duration of sunitinib administration was 7 months. The median maximum reduction rate of sunitinib was 18.3%. Tumor response was classified according to the Response Evaluation Criteria in Solid Tumors: 20 cases (33.3%) showed partial response, 29 cases (48.3%) showed stable disease, and 11 cases (18.3%) showed progressive disease. In a multivariate analysis of factors contributing to progression-free survival from the start of sunitinib administration, only histologically poor differentiation was a significant factor (p = 0.010). Progression-free survival and overall survival were significantly better in patients with NET-G3 than that in patients with NEC-G3 (p = 0.005, p = 0.012), while it was not different between those with NET-G3 and those with NET-G1/2.

CONCLUSION

Our results indicate that sunitinib is as effective for NET-G3 as for NET-G1/2.

Irinotecan plus cisplatin followed by octreotide long-acting release maintenance treatment in advanced gastroenteropancreatic neuroendocrine carcinoma: IPO-NEC study

There have been very few prospective studies of first-line chemotherapy on advanced gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC). This phase II study assessed the activity and safety of irinotecan plus cisplatin (IP) followed by octreotide long-acting release (LAR) maintenance treatment in advanced GEP-NEC. Forty patients were treated and eighteen patients (45.0%) had a partial response. The median progression-free survival (PFS) and overall survival (OS) were 5.7 months and 12.9 months, respectively. Because GEP-NECs are heterogeneous, a subgroup analysis was conducted by dividing all patients into a high proliferation neuroendocrine tumor (NET) group (well differentiated neuroendocrine neoplasms with a Ki-67 level between 20-60%) or a poorly differentiated NEC (PDNEC) group. Compared with the PDNEC group, the patients in high proliferation NET group had a lower response rate (0% versus 51.4%) but longer PFS (8.9 versus 5.7 months) and received more octreotide LAR treatment (median cycles, 7 versus 3). The most common toxicities included grade 3/4 leukopenia/neutropenia (60%), nausea/vomiting (17.5%) and diarrhea (12.5%). Therefore, IP is an active regimen in patients with advanced GEP-PDNEC and should probably not be given to patients with advanced high proliferative NET. The benefit of octreotide LAR maintenance therapy on high proliferation NETs requires further study.

Neuroendocrine Carcinoma of the Stomach: A Response to Combination Chemotherapy Consisting of Ramucirumab Plus Paclitaxel

Extrapulmonary neuroendocrine carcinoma (NEC) is a rare disease, and there is no standard chemotherapy. A 73-year-old man was diagnosed with advanced gastric NEC. He received chemotherapy of irinotecan plus cisplatin, and amrubicin monotherapy. After failure of second-line chemotherapy, he received ramucirumab plus paclitaxel; this treatment was chosen because vascular endothelial growth factor 2 was strongly expressed in the tumor endothelial cells. After two cycles, his NEC had markedly reduced in size, and he continued with this treatment for over eight months. In this case, the combination of an anti-angiogenic inhibitor and a cytotoxic agent was highly effective for gastric NEC.

A case of small intestinal neuroendocrine carcinoma diagnosed using double-balloon endoscopy with long-term survival

Neuroendocrine neoplasms, including neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs), are rare epithelial tumors with a predominant neuroendocrine differentiation. Compared with NETs, NECs have been reported to be rarer and have a poorer prognosis. We present a rare case of small bowel NEC diagnosed using double-balloon endoscopy (DBE) and the long-term survival accomplished via intensive therapy. DBE revealed an ulcerative tumor in the deep jejunum, and biopsy specimens showed large and highly dysplastic tumor cells; immuno-histological synaptophysin and chromogranin A tests were positive, and the Ki-67 index was more than 90%. Partial intestinal resection without complete lymph node dissection was performed and, postoperatively, chemotherapy was administered. The patient was observed for 3 years after chemotherapy, and complete remission was maintained.

The efficacy of chemotherapy and operation in patients with colorectal neuroendocrine carcinoma

BACKGROUND

Colorectal neuroendocrine carcinoma (CRNEC) is a rare type of malignancy and is quite aggressive with dismal prognosis. Neither large-scale retrospective studies nor prospective studies have been performed to evaluate the prognostic value of adjuvant chemotherapy in patients with CRNEC.

METHODS

Using the Surveillance, Epidemiology, and End Results-Medicare database, 318 elderly patients who were diagnosed with high-grade colorectal neuroendocrine tumors were included. The survival benefit was evaluated using a Cox proportional hazards model and propensity score-matched techniques.

RESULTS

Among patients with stage I-III CRNEC, there was also no significant difference in cancer-specific survival (CSS) (P = 0.898) or overall survival (OS) (P = 0.539) between the 5-fluorouracil (5-FU) and the no chemotherapy groups. Meanwhile, the etoposide + platinum (EP) regimen showed no improved survival in patients with stage I-III CRNEC compared with the no chemotherapy group. For stage IV CRNEC, there was no significant difference between operation group and no operation group in CSS (P = 0.317) or OS (P = 0.385). Both 5-FU and EP regimens improved the CSS (for 5-FU, hazard ratio [HR] = 0.257, 95% confidence interval [CI] = 0.134-0.491, P < 0.001; for EP, HR = 0.348, 95% CI = 0.192-0.631, P = 0.001) and OS (for 5-FU, HR = 0.274, 95% CI = 0.149-0.502, P < 0.001; for EP, HR = 0.345, 95% CI = 0.194-0.612, P < 0.001) of patients in stage IV CRNEC.

CONCLUSIONS

Our findings demonstrated that neither the 5-FU based nor EP chemotherapy regimens improved the CSS or OS for patients with stage I-III CRNEC. And for stage IV CRNEC, chemotherapy is an independent prognostic factor for CSS and OS, while operation could not improve the CSS or OS for patients with stage IV CRNEC.

Downgrading of a G3 Neuroendocrine Tumor to a G2 Tumor: Can First-Line Cytotoxic Chemotherapy Change the Tumor Biology?

The antiproliferative treatment options for neuroendocrine tumors (NET)/neuroendocrine carcinomas of the gastrointestinal tract critically depend on the proliferation rate, evaluated by immunohistochemical staining for Ki-67. According to their grading, tumors are treated with somatostatin analogs, mTOR inhibitors, or cytotoxic substances. This case illustrates downgrading of a primarily highly proliferative NET achieved by a variation of cytotoxic chemotherapy regimens, followed by a combination therapy using everolimus together with lanreotide. The latter medication might lead to a good clinical response as far as tumor growth is concerned.

Chemotherapy in NETs: When and how

The majority of neuroendocrine tumours (NETs) are well-differentiated tumours that follow an indolent course, in contrast to a minority of poorly differentiated neuroendocrine carcinomas (NECs) which exhibit an aggressive course and assocaited with an overall short survival. Although surgery is the only curative treatment for NETs it is not always feasible,necessitating the application of other therapies including chemotherapy. Streptozotocin (STZ)-based regimens have long been used for advanced or metastatic well-to-moderately differentiated (G1-G2) NETs, especially those originating from the pancreas (pNETs). In poorly differentiated grade 3 (G3) tumours, platinum-based chemotherapy is recommended as first-line therapy, albeit without durable responses. Although data for temozolomide (TMZ)-based chemotherapy are still evolving, this treatment may replace STZ-based regimens in pNETs due to its better tolerability and side effect profile. In addition, there is evidence that TMZ could also be used in the subgroup of well-differentiated G3 NETs. There is less clear-cut evidence of a benefit for chemotherapy in intestinal NETs, but still evolving data suggest that TMZ may be efficacious in particular patients. In lung and thymic carcinoids, chemotherapy is reserved for patients with progressive metastatic disease in whom other treatment options are unavailable. Overall, chemotherapy is indicated in patients who have progressed on first-line treatment with somatostatin analogues, have extensive tumour load or exhibit rapid growth following a period of follow-up, and/or have a high proliferative rate; it may occasionally can be used in a neo-adjuvant setting. Prospective randomised studies are awaited to substantiate the role of chemotherapy in the therapeutic algorithm of NETs along with other evolving treatments.

Gastric Adenocarcinoma with Dual Differentiation toward Neuroendocrine and α-Fetoprotein-Producing Features: Report of 2 Cases

Some gastric carcinomas show composite features of neuroendocrine carcinoma (NEC) and α-fetoprotein (AFP)-producing carcinoma, which are very rare; only a few cases have been reported to date. We reviewed an additional 2 such cases of gastric carcinoma, which were both advanced aggressive tumors showing regional lymph node metastasis and distant metastasis. Both cases were accompanied by ordinary adenocarcinoma forms, implying that they had preceded the NEC and AFP-producing carcinoma components. A distinctive feature was the finding suggestive of dual differentiation of tumor cells to neuroendocrine and AFP-producing phenotypes, which was identified even in the metastatic tumor in the regional lymph node. Because both tumors predominantly showed poorly differentiated forms, the final pathologic diagnosis must rely on the immunohistochemistry. Pathologists should always keep in mind the existence of such tumors for the correct diagnosis of some gastric carcinomas with specific phenotypes, especially in pathologic diagnosis on biopsy.

Medical Therapy of Gastrointestinal Neuroendocrine Tumors

Intestinal neuroendocrine tumors (NETs) constitute a heterogeneous group with duodenal, small intestinal, colonic and rectal NETs. They constitute more than half of all NETs, with the highest frequencies in the rectum, small intestine, and colon. The tumor biology varies with the location of the primary tumor as well as with the grade and staging of the tumor. Small intestinal NETs usually present low proliferation and are treated in the first line with somatostatin analogs according to current guidelines. If progression occurs, one can add interferon alpha or change the treatment to everolimus. Peptide receptor radionuclide therapy (PRRT) with Lutetium¹⁷⁷-DOTATATE can be an option in the future after registration of the compound. Rectal tumors are usually small when they metastasize; they can be treated with somatostatin analogs but more so with PRRT, while another option is of course everolimus. Colonic NETs are more aggressive than the rest of intestinal NETs and will be treated with everolimus, sometimes in combination with somatostatin analogs based on positive scintigraphy. Another option is a cytotoxic agent such as streptozotocin plus 5-fluorouracil (5-FU) or temozolomide plus capecitabine. The most aggressive tumors, i.e. neuroendocrine carcinoma G3, are treated with a platin-based therapy plus etoposide; if they present with a lower proliferation, i.e. <50%, temozolomide plus capecitabine plus bevacizumab can also be attempted. Duodenal NETs are mostly treated similar to pancreatic NETs, either with cytotoxic agents, streptozotocin plus 5-FU, or temozolomide plus capecitabine, or with targeted agents such as everolimus.

Mixed adenoneuroendocrine carcinoma of the distal bile duct: A case report

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Mixed adenoneuroendocrine carcinomas (MANECs) of the distal bile duct are extremely rare.

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The treatment of MANECs of the bile duct remains controversial and the prognosis is poor.

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Larger studies are required to establish standard treatment regimens of MANECs of the bile duct.

Introduction

Mixed adenoneuroendocrine carcinomas (MANECs) of the distal bile duct are extremely rare, and only a few cases have been reported in the English literature.

Presentation of case

An 82-year-old man was referred to our hospital for increasing biliary enzymes. Abdominal computed tomography (CT) showed enlargement of the intrahepatic bile ducts and stenosis of the distal bile duct. Endoscopic retrograde cholangiopancreatography showed stenosis of the distal bile duct and a high-density signal at the same site on diffusion weighted imaging. PET-CT showed increased FDG accumulation (SUVmax: 4.5) at the distal bile duct stenosis. Biopsy specimens obtained by endoscopic ultrasonography-guided fine-needle aspiration revealed adenocarcinoma. The patient was diagnosed with adenocarcinoma of the distal bile duct and underwent subtotal stomach-preserving pancreaticoduodenectomy with regional lymph node dissection. The resected distal bile duct tumor was 18 × 14 × 12 mm in diameter. Hematoxylin and eosin staining revealed a composite carcinoma with adenocarcinoma and non-adenocarcinoma elements. The non-adenocarcinoma component stained positive for synaptophysin and chromogranin A. The Ki-67 labeling index was 37%. The non-adenocarcinoma component was therefore diagnosed as a neuroendocrine carcinoma. The two composite carcinoma was diagnosed as MANEC of the distal bile duct. The patient was treated with surgery alone and he remained disease-free for 7 months after the surgery.

Discussion

The treatment of MANECs of the bile duct remains controversial and the prognosis is poor.

Conclusions

There is no standard treatment for MANECs of the bile duct. Larger studies are required to establish standard treatment regimens.

Mixed adenoneuroendocrine carcinoma derived from the cystic duct: A case report

INTRODUCTION

Mixed adenoneuroendocrine carcinomas (MANECs) derived from cystic duct are extremely rare.

PRESENTATION OF CASE

An 80-year-old woman was admitted to the department of surgery, Onomichi general hospital with abnormal liver function and jaundice. Enhanced abdominal computed tomography (CT) detected a well-enhanced papillary tumor in the cystic duct, which protruded into the common bile duct. The intrahepatic bile duct was dilated due to tumor obstruction. The entire tumor showed high intensity in T2-weighted magnetic resonance imaging (MRI) imaging. Endoscopic retrograde cholangiopancreatography (ERCP) showed that the tumor ranged from part of communication of three ducts (cystic, common hepatic and common bile duct), to the middle of common bile duct. Biliary cytology determined a class V malignancy (adenocarcinoma). Endoscopic ultrasound determined that the tumor was primarily at the cystic duct with heterogeneous echoic pattern, which extended into the common bile duct. The preoperative diagnosis was cystic duct carcinoma (T3N0M0, StageIIIA). An extended cholecystectomy with regional lymph nodes dissection was performed. Histologically, the tumor had components of both well-differentiated tubular adenocarcinoma and neuroendocrine carcinoma, which is classified as MANECs according to the 2010 WHO classification of endocrine tumors. Eight months after surgery, multiple liver metastases were discovered, and treatment with adjuvant chemotherapy was initiated.

DISSCUSION

We present a rare case of MANECs derived from cystic duct. Until now, an established adjuvant systemic chemotherapy has not emerged, and curative resection, with poor long-term prognosis, remains the only treatment option.

CONCLUSION

Though standards of treatment for MANECs have not been established,multidisciplinary theraphy is necessary to improve outcome.

Neuroendocrine Gastroenteropancreatic Tumors: Where Are We?

AIMS

Neuroendocrine gastroenteropancreatic tumors are infrequently found neoplasms. Our objective was to analyze the survival rates for all sites that they occur in by studying different variables.

MATERIALS AND METHODS

A retrospective study was carried out using records for a 7-year period from January 1, 2008 to December 31, 2014 on neuroendocrine gastroenteropancreatic tumors patients diagnosed at the Pontevedra-Salnés Hospital Complex. The variables used were as follows: age at diagnosis, tumor size, presence or absence of metastases at diagnosis, cell proliferation index, Ki-67 of each tumor, treatments received, postdiagnosis survival time, existence or not of tumor progression, and time from diagnosis to progression and from diagnosis to mortality. In relation to treatments, the information recorded was whether the treatment was endoscopic, surgical, or pharmacological.

RESULTS

Ninety-three neuroendocrine tumors made up a ratio of 4.42 cases per 100,000 inhabitants per annum. The median patient follow-up time was 44 months. The overall 5-year survival rate for patients who were followed up for a minimum of 60 months (49 patients) was 65.3%. The progression-free survival was 75.6% for 41 patients who were followed up for a minimum of 60 months. The survival rate for patients receiving endoscopic treatment was 100%, as there was no patient mortality recorded for those treated by endoscopic resection during the follow-up period.

CONCLUSION

Pancreatic neuroendocrine tumors may be managed conservatively in elderly patients by either monitoring them with imaging studies or treating them with somatostatin analogs. In the case of digestive tract tumors (stomach, duodenum, and rectum) that meet the criteria for endoscopic resection, this is a reliable and safe technique in the long term.

Neuroendocrine Cancer, Therapeutic Strategies in G3 Cancers

BACKGROUND

According to the latest WHO classification, neuroendocrine neoplasm (NEN) G3 of the gastrointestinal tract is defined by a proliferation index Ki67 above 20%. Gastrointestinal neuroendocrine carcinoma (NEC) is a rare and highly aggressive malignancy and despite responsiveness to chemotherapy, overall survival is poor. In the last 3-4 years, the heterogeneity of the NEN G3 group has become evident.

SUMMARY

In addition to the proliferative activity, the tumour differentiation seems to play a major role, further dividing the NEN G3 group into neuroendocrine tumour (NET) G3 and NEC. NET G3 often arise in the pancreas, and their median proliferation rate is lower and prognosis is better as compared to NEC. However, NET G3 show a limited response to platinum-based chemotherapy. Lack of specific data for NET G3 hampers clear therapeutic recommendations. Cisplatin combined with etoposide is the established standard regimen for advanced gastrointestinal NEC. Substituting carboplatin for cisplatin or irinotecan for etoposide is considered alternative first-line regimen. There is no standard second-line treatment; options are discussed within this review.

KEY POINTS

(1) In NEN G3, the distinction between NET G3 and NEC G3 is clinically and prognostically meaningful. (2) Platinum-based chemotherapy remains the recommended first-line treatment in metastasized NEC patients. (3) There is no established standard for NET G3; treatments established for NET G2 such as temozolomide-based chemotherapy or peptide receptor radiotherapy may be considered. (4) Specific trials for NET G3 are necessary. (5) New therapies for NEC are urgently needed. Checkpoint inhibitors should be evaluated.

Systemic chemotherapy with pronounced efficacy and neutropenia in a granulocyte-colony stimulating factor-producing advanced gastric neuroendocrine carcinoma

An advanced granulocyte-colony stimulating factor (G-CSF)-producing tumor is rare, and it exhibits leukocytosis in association with high serum G-CSF levels. A 67-year-old male with a 1-month history of bloody emesis and black stools was revealed to exhibit leukocytosis, anemia and a high serum concentration of G-CSF. During a gastrointestinal endoscopy, an ulcerating tumor was identified in the stomach. Computed tomography and a fluorodeoxyglucose-positron emission tomography scan demonstrated direct invasion of the gastric tumor into the transverse colon, regional lymphadenopathy, lung nodules and diffuse high uptake of FDG in bone marrow. The histological diagnosis was a G-CSF-producing neuroendocrine carcinoma (NEC) (tumor 4b, node 2, metastasis 1, pulmonary, clinical stage IV). Systemic chemotherapy consisting of cisplatin and irinotecan was started. Common terminology criteria of adverse events grade 3 tumor lysis syndrome and gastric penetration appeared. Grade 4 neutropenia lasted for 10 days despite intensive G-CSF administration. Prominent shrinkage of the primary and the metastatic tumors was observed subsequent to 3 cycles of chemotherapy. Total gastrectomy and resection of the transverse colon were subsequently performed. Systemic chemotherapy was effective for a G-CSF-producing advanced gastric NEC with careful monitoring and appropriate supportive care for severe adverse events.

The impact of pathologic differentiation (well/poorly) and the degree of Ki-67 index in patients with metastatic WHO grade 3 GEP-NECs

We investigated the impact of pathologic differentiation (well or poorly differentiated) in metastatic grade 3 GEP-NEC patients receiving etoposide and platinum (EP)-based therapy, and evaluated a more exact Ki67 index cut-off point to select patients with grade 3 GEP-NEC who might benefit from EP-based therapy. A total of 31 patients with metastatic grade 3 GEP-NECs receiving EP-based therapy were included in this study. Primary sites included 13 foregut-derived GEP-NECs [stomach (n = 4), duodenum (n = 4), and pancreas (n = 5)] and 2 hindgut-derived GEP-NECs of the rectum. 14 patients had well differentiated (WD) and 17 had poorly differentiated (PD). Between WD and PD grade 3 GEP-NECs, there was a significant difference in the distribution of Ki67 index. There was no significant difference of treatment efficacy between WD and PD grade 3 GEP-NECs (RR; 35.7% vs. 41.2%, p = 0.525). Tumor response to EP occurred in 5 of 7 patients with Ki67 > 60% and 7 of 24 with Ki67 ≤ 60%, which was significantly different (RR; 71.4% vs. 29.2%, P = 0.043). Among grade 3 GEP-NECs, there was a significant difference in ranges of Ki67 index between WD and PD NECs. Higher levels (> 60%) of Ki67 index might be a predictive marker for efficacy of EP as a standard regimen in grade 3 GEP-NECs.

Dynamic computed tomography is useful for prediction of pathological grade in pancreatic neuroendocrine neoplasm

BACKGROUND AND AIM

Pathological grading is important in defining the therapeutic strategy in pancreatic neuroendocrine neoplasm (PNEN) but is difficult for unresectable cases. Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) is useful in the diagnosis of PNEN, but its usefulness for pathological grading is not well established. No studies have examined the diagnostic ability of dynamic computed tomography (CT) for pathological grading of PNEN. We investigated the usefulness of EUS-FNA and dynamic CT in the diagnosis and pathological grading of PNEN.

METHODS

In this retrospective study, 39 PNEN patients finally diagnosed via EUS-FNA and/or surgical resection underwent dynamic CT. Pathological samples were diagnosed based on WHO2010; staging was based on the European Neuroendocrine Tumor Society classification. The proportion of the quantification value in the tumor to the pancreatic parenchyma in arterial phase was defined as the CT ratio. Immunohistochemical staining with CD31 was performed to evaluate microvessel density (MVD). We evaluated the relationship between pathological grade, CT ratio, and MVD.

RESULTS

By using EUS-FNA, 35 of 39 (90%) cases were diagnosed as PNEN. As for pathological grade, 15 of 35 (43%) cases could be identified correctly. CT ratio could predict pathological Grade 3 disease. The sensitivity, specificity, and diagnostic accuracy were 100%, 94%, and 95%. MVD was significantly correlated with CT ratio (r = 0.83, P < 0.0001) and pathological grade (P = 0.0074).

CONCLUSIONS

Computed tomography ratio has a relationship with pathological grade in PNEN, which would help decide therapeutic strategy in unresectable cases and cases in which pathological grading is difficult.

A case of mixed adenoneuroendocrine carcinoma of the pancreas: Immunohistochemical analysis for histogenesis

RATIONALE

Tumors with multiple histological features, such as adenocarcinomas and neuroendocrine carcinomas, were included as a new category of neuroendocrine carcinomas in the 2010 World Health Organization classification. We recently experienced a rare case of a pancreatic carcinoma with both adenocarcinoma and neuroendocrine carcinoma components, a so-called mixed adenoneuroendocrine carcinoma.

PATIENT CONCERNS AND DIAGNOSIS

A 66-year-old man was referred to our hospital with obstructive jaundice. Contrast-enhanced computed tomography images indicated a tumor located at the pancreatic head measuring 3.0 × 2.5 cm in diameter and invading the common bile duct. Cytological examination of the bile juice obtained by endoscopic retrograde cholangiopancreatography revealed adenocarcinoma cells. Pancreaticoduodenectomy was performed safely as radical resection.

INTERVENTIONS

Microscopically, the resected tumor consisted of tightly intermingled adenocarcinoma and neuroendocrine carcinoma components. On the immunohistochemical examination, p53 was ubiquitously positive in both components, whereas chromogranin A, synaptophysin and neuron-specific enolase, neuroendocrine markers, were limited to the neuroendocrine carcinoma component.

OUTCOMES

Thus, such features of both adenocarcinoma and neuroendocrine carcinoma observed microscopically and immunohistochemically seemed to indicate a composite tumor.

LESSONS

The findings of this case suggest that adenocarcinoma and neuroendocrine carcinoma may be derived from a single cancer stem cell.

Pancreatic Neuroendocrine Neoplasms: Basic Biology, Current Treatment Strategies and Prospects for the Future

Pancreatic neuroendocrine neoplasms (pNENs) are rare tumors accounting for only 1%–2% of all pancreatic tumors. pNENs are pathologically heterogeneous and are categorized into three groups (neuroendocrine tumor: NET G1, NET G2; and neuroendocrine carcinoma: NEC) on the basis of the Ki-67 proliferation index and the mitotic count according to the 2010 World Health Organization (WHO) classification of gastroenteropancreatic NENs. NEC in this classification includes both histologically well-differentiated and poorly differentiated subtypes, and modification of the WHO 2010 classification is under discussion based on genetic and clinical data. Genomic analysis has revealed NETs G1/G2 have genetic alterations in chromatin remodeling genes such as MEN1, DAXX and ATRX, whereas NECs have an inactivation of TP53 and RB1, and these data suggest that different treatment approaches would be required for NET G1/G2 and NEC. While there are promising molecular targeted drugs, such as everolimus or sunitinib, for advanced NET G1/G2, treatment stratification based on appropriate predictive and prognostic biomarkers is becoming an important issue. The clinical outcome of NEC is still dismal, and a more detailed understanding of the genetic background together with preclinical studies to develop new agents, including those already under investigation for small cell lung cancer (SCLC), will be needed to improve the prognosis.

Design and Validation of the GI-NEC Score to Prognosticate Overall Survival in Patients With High-Grade Gastrointestinal Neuroendocrine Carcinomas

Background

Prognostic markers for risk stratification of patients with gastrointestinal high-grade neuroendocrine carcinomas (GI-NECs) are lacking; we designed and validated a prognostic score for overall survival (OS).

Methods

Consecutive patients diagnosed in five neuroendocrine specialist European centers were included. Patients were divided into three cohorts: a training cohort (TC), an external validation cohort (EVC), and a prospective validation cohort (PVC). Prognostic factors were identified by log-rank test, Cox-regression, and logistic regression analyses. The derived score was internally and externally validated. All statistical tests were two-sided.

Results

Of 395 patients screened, 313 were eligible (TC = 109 patients, EVC = 184 patients, and PVC = 20 patients). The derived prognostic score included five variables: presence of liver metastases, alkaline phosphatase (ALK), lactate dehydrogenase (LDH), Eastern Cooperative Oncology Group performance status (ECOG PS), and Ki67. In multivariable analysis, the score was prognostic for OS (hazard ratio [HR] = 1.86, 95% confidence interval [CI] = 1.47 to 2.35, P < .001) and had good discrimination (C-index = 0.76) and calibration (mean error = 0.021, 90th percentile = 0.037) in the TC. These results were validated in the EVC and PVC, in which our score was able to prognosticate for OS when adjusted for other prognostic variables in the multivariable analysis (HR = 1.85, 95% CI = 1.27 to 2.71, P = .001; and HR = 4.51, 95% CI = 1.87 to 10.87, P = .001, respectively). The score classified patients into two groups with incremental risk of death: group A (0-2 points, 181 patients [63.9%], median OS = 19.4 months, 95% CI = 16.1 to 25.1) and group B (3-6 points, 102 patients [36.1%], median OS = 5.2 months, 95% CI = 3.6 to 6.9).

Conclusions

The GI-NEC score identifies two distinct patient cohorts; it provides a tool for clinicians when making treatment decisions and may be used as a stratification factor in future clinical trials.

Subtype classification and management of gastric neuroendocrine neoplasms

Gastric neuroendocrine neoplasms (g-NENs) are a group of heterogeneous tumors arising from endocrine cells in the stomach. Because of the low incidence, clinical misdiagnosis and mismanagement of g-NENs may occasionally occur. In this review, I summarize the epidemiology, pathology, tumor staging, clinical classification, diagnostic algorithm, treatment and prognosis of g-NENs, to explain the standard diagnosis and management, as well as the latest advances in g-NEN research. The author advocates the four-type classification of g-NENs, and emphasizes that type 1 g-NENs are a recurrent disease which needs long-term follow-up. Molecular mechanism of recurrence of and medical therapy for type 1 g-NENs are the future research direction for neuroendocrine neoplasms.

Systemic therapies for advanced gastroenteropancreatic neuroendocrine tumors

Neuroendocrine tumors are a heterogeneous group of malignancies, characterised by production of hormones and vasoactive peptides. The incidence of gastroenteropancreatic neuroendocrine tumors (GEP-NET) is rising, and they have the highest prevalence amongst upper gastro-intestinal tumors. Diagnosis remains challenging due to wide variations in presentation and slow onset of symptoms. A multi-disciplinary approach is vital in appropriately managing the diverse spectrum of GEP-NET. Areas covered: Investigations in GEP-NET and biomarkers are described. Moreover, all available therapeutic options for GEP-NET including surgery, somatostatin analogues, targeted agents, Peptide Receptor Radionuclide Therapy and chemotherapy are also discussed. Expert commentary: The landscape of management has changed significantly in the last decade as a result of many practice-changing clinical trials. Long- acting somatostatin analogues are used not only for symptom control but also for their anti-proliferative effect. Targeted agents, such as everolimus and sunitinib, have improved PFS in GEP-NET. The recently presented NETTER-1 trial confirms the place of peptide receptor radionuclide treatment (PRRT) in treating NET. While chemotherapy remained an important option for high grade tumors. Despite promising results from recent trials, challenges include establishing the optimal sequencing of therapies to optimize outcome and preserve the quality of life.