Poorly differentiated gastro-entero-pancreatic neuroendocrine carcinomas: Are they really heterogeneous? Insights from the FFCD-GTE national cohort

Nasopharyngeal neuroendocrine neoplasms: Systematic review of the literature and case presentation

Most of neuroendocrine neoplasms (NENs) are located in the gastrointestinal tract and lung, and they are rarely found on the upper aero-digestive tract, which limit the current literature about nasopharyngeal NENs. This systemic review will summarize the clinical, pathological features and optimal diagnosis and management of different types of nasopharyngeal NENs (NP NENs). In-addition, we herein report an EBV negative TP53-mutated/ Rb-wild type nasopharyngeal neuroendocrine carcinoma (NEC) in a young man in which touch preparation cytology studies were integral to establishing a definitive diagnosis. To our knowledge, only very few cases of primary neuroendocrine carcinoma of the nasopharynx have been reported in the literature and the reports of these cases have not included detailed description of different types and how to optimally diagnose and manage them. In this abstract, we also highlighted the evidence about the safety of using growth factors in patients with sickle cell anemia who are receiving cytotoxic chemotherapy.

Neuroendocrine Carcinomas of the Digestive Tract: What Is New?

Neuroendocrine carcinomas (NEC) are rare tumors with a rising incidence. They show poorly differentiated morphology with a high proliferation rate (Ki-67 index). They frequently arise in the lung (small and large-cell lung cancer) but rarely from the gastrointestinal tract. Due to their rarity, very little is known about digestive NEC and few studies have been conducted. Therefore, most of therapeutic recommendations are issued from work on small-cell lung cancers (SCLC). Recent improvement in pathology and imaging has allowed for better detection and classification of high-grade NEN. The 2019 World Health Organization (WHO) classification has described a new entity of well-differentiated grade 3 neuroendocrine tumors (NET G-3), with better prognosis, that should be managed separately from NEC. NEC are aggressive neoplasms often diagnosed at a metastatic state. In the localized setting, surgery can be performed in selected patients followed by adjuvant platinum-based chemotherapy. Concurrent chemoradiotherapy is also an option for NEC of the lung, rectum, and esophagus. In metastatic NEC, chemotherapy is administered with a classic combination of platinum salts and etoposide in the first-line setting. Peptide receptor radionuclide therapy (PRRT) has shown positive results in high-grade NEN populations and immunotherapy trials are still ongoing. Available therapies have improved the overall survival of NEC but there is still an urgent need for improvement. This narrative review sums up the current data on digestive NEC while exploring future directions for their management.

FOLFIRINEC: a randomized phase II trial of mFOLFIRINOX vs platinum-etoposide for metastatic neuroendocrine carcinoma of gastroenteropancreatic or unknown origin

BACKGROUND

Poorly differentiated neuroendocrine carcinomas (NEC) are rare diseases with a poor prognosis. Platinum-etoposide (PE) has been the recommended first-line treatment for decades. FOLFIRINEC (NCT04325425) is a national multicenter randomized phase II study which aims to challenge this standard regimen.

METHODS

The primary objective is to compare the median progression-free survival (PFS) under mFOLFIRINOX versus PE. The secondary objectives are to evaluate the objective response rates (ORR), median overall survival (OS), safety and quality of life. The associated real-time translational study will establish a molecular profile for each patient enrolled.

MAIN INCLUSION CRITERIA ARE

NEC of gastroenteropancreatic (GEP) or unknown origin, metastatic and RECIST 1.1 evaluable disease, tumor sample available and no contraindication to chemotherapy. Patients will be randomized 1:1 between PE every 21 days for 6-8 cycles and mFOLFIRINOX every 14 days for up to 12 cycles and stratified according to center, performance status, Ki67 and pathological subtype. This trial will randomize 218 patients (24 months of follow-up) to have 80% power to detect an improvement of the median PFS from 5 months under PE to 7.5 months under mFOLFIRINOX (HR of 0.67, α =5%, two-sided). An intermediate analysis is planned at 50% of events. Recruitment started on October 20, 2020.

Systemic Treatment of Gastroenteropancreatic Neuroendocrine Carcinoma

OPINION STATEMENT

Treatment recommendations for advanced gastroenteropancreatic neuroendocrine carcinomas (GEP-NEC) are based on uncontrolled, mainly retrospective data. Chemotherapy can offer palliative relief, but long-lasting complete responses or cures are rare. The European Neuroendocrine Tumour Society (ENETS) and European Society for Medical Oncology (ESMO) recommend platinum-based chemotherapy as first-line treatment. This has been the golden standard since the late 1980s and has been evaluated in mostly retrospective clinical studies. However, progression is inevitable for most patients. Unfortunately, data on effective second-line treatment options are scant, and ENETS and ESMO recommendations propose fluorouracil- or temozolomide-based chemotherapy schedules. As such, there is a huge unmet need for improved care. Improved knowledge on GEP-NEC biology may provide a pathway towards more effective interventions including chemotherapy, targeted gene therapy, peptide receptor radionuclide therapy, as well as immune checkpoint inhibitors. The review summarises this current state of the art as well as the most promising developments for systemic therapy in GEP-NEC patients.

Digestive Well-Differentiated Grade 3 Neuroendocrine Tumors: Current Management and Future Directions

Digestive well-differentiated grade 3 neuroendocrine tumors (NET G-3) have been clearly defined since the 2017 World Health Organization classification. They are still a rare category lacking specific data and standardized management. Their distinction from other types of neuroendocrine neoplasms (NEN) not only lies in morphology but also in genotype, aggressiveness, functional imaging uptake, and treatment response. Most of the available data comes from pancreatic series, which is the most frequent tumor site for this entity. In the non-metastatic setting, surgical resection is recommended, irrespective of grade and tumor site. For metastatic NET G-3, chemotherapy is the main first-line treatment with temozolomide-based regimen showing more efficacy than platinum-based regimen, especially when Ki-67 index <55%. Targeted therapies, such as sunitinib and everolimus, have also shown some positive therapeutic efficacy in small samples of patients. Functional imaging plays a key role for detection but also treatment selection. In the second or further-line setting, peptide receptor radionuclide therapy has shown promising response rates in high-grade NEN. Finally, immunotherapy is currently investigated as a new therapeutic approach with trials still ongoing. More data will come with future work now focusing on this specific subgroup. The aim of this review is to summarize the current data on digestive NET G-3 and explore future directions for their management.

Acute-onset paraneoplastic cerebellar degeneration secondary to neuroendocrine carcinoma with atypical prognosis: a case report

Paraneoplastic cerebellar degeneration (PCD) is a neurological syndrome that is likely caused by tumor-induced autoimmunity against the cerebellum. Neuroendocrine carcinoma (NEC) is a type of neoplasm with high-grade malignant histology and biological behavior. The prognosis for both PCD and NEC is typically poor. We report a case of PCD secondary to metastatic NEC in the lymph nodes, with an unknown primary origin. The case presented acute cerebellar manifestations with typical neuroimaging findings, but with atypical prognosis after lymph node dissection. Neurological symptoms can provide clues to potential tumors, and early antitumor treatment may have contributed to the positive prognosis of PCD secondary to NEC in the present case.

Surgery of the primary tumour in 201 patients with high-grade gastroenteropancreatic neuroendocrine and mixed neuroendocrine-non-neuroendocrine neoplasms

The benefit of surgery in high-grade gastroenteropancreatic neuroendocrine neoplasms (GEP NEN) and mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) is uncertain. The present study aimed to investigate outcomes after tumour surgery in patients with high-grade (Ki-67 > 20%) GEP NEN or MiNEN stage I-III or stage IV. We analysed data from patients treated in the period 2007-2015 at eight Nordic university hospitals. Overall survival (OS) and progression-free survival (PFS)/disease-free survival (DFS) were analysed by Kaplan-Meier estimates. Prognostic factors were evaluated using Cox regression. We included 201 surgically resected patients, 143 stage I-III and 58 stage IV, with 68% having neuroendocrine carcinoma, 23% MiNEN, 5% neuroendocrine tumour G3 and 4% uncertain NEN G3. Primary tumours were located in colon/rectum (52%), oesophagus/cardia (19%), pancreas (10%), stomach (7%), jejunum/ileum (5%), duodenum (4%), gallbladder (2%) and anal canal (1%). For patients with stage I-III, median DFS was 12 months (95% confidence interval [CI] = 5.5-18.5) and median OS was 32 months (95% CI = 24.0-40.0). For patients with stage I-III and an R0 resection, median DFS was 21 months (95% CI = 4.9-37.1) and median OS was 39 months (95% CI = 25.0-53.0). For patients with stage IV, median PFS/DFS was 4 months (95% CI = 1.9-6.1) and median OS was 11 months (95% CI = 4.8-17.2). For patients with stage IV and an R0 resection, median DFS was 6 months (95% CI = 0-16.4) and median OS was 32 months (95% CI = 25.5-38.5). Performance status > 1 and colorectal primary were associated with poor prognosis. There was no difference in survival between patients with high-grade GEP NEN and MiNEN. Surgery of the primary tumour in patients with loco-regional high-grade GEP NEN or MiNEN led to good long-term results and should be considered if an R0 resection is considered achievable. Highly selected patients with stage IV disease may also benefit from surgery.

The value of MRI in identifying pancreatic neuroendocrine tumour G3 and carcinoma G3

AIM

To explore the magnetic resonance imaging (MRI) differences between pancreatic neuroendocrine tumour grade 3 (pNET-G3) and pancreatic neuroendocrine carcinoma grade 3 (pNEC-G3).

MATERIALS AND METHODS

Between 2009 and 2019, 31 patients underwent pNEN-G3 resection with preoperative MRI in two local hospitals in China. The 31 patients were assigned to a pNET-G3 group (n=13) or a pNEC-G3 group (n=18). The MRI findings between the groups were compared.

RESULTS

There was no statistically significant difference between the two groups in lesion size, clinical characteristics, or laboratory indexes. The lesions showed high or slightly higher signal on diffusion-weighted imaging and decreased apparent diffusion coefficient (ADC) values, which differed between the two groups (p=0.013). The difference between the groups regarding positive enhancement integral, arterial phase and portal phase signal enhancement ratio were statistically significant; however, the delayed phase signal enhancement ratio was not significantly different.

CONCLUSIONS

pNET-G3 and pNEC-G3 showed different characteristics on MRI. In particular, the ADC value and dynamic enhanced imaging could have an important role in distinguishing between the two.

Temozolomide alone or in combination with capecitabine in patients with advanced neuroendocrine neoplasms: an Italian multicenter real-world analysis

PURPOSE

Temozolomide (TEM) has been reported to be active alone or in combination with capecitabine (CAP) in patients with neuroendocrine neoplasms (NENs). We retrospectively evaluated activity and toxicity of TEM-based chemotherapy in patients with advanced NENs and explored the potential correlation with clinical/biological factors.

METHODS

Patients received oral TEM alone or in combination with CAP. Objective response rate (ORR) [complete response + partial response (PR)], median progression-free survival (mPFS), and toxicity were calculated. The O6-methylguanine-DNA-methyltransferase (MGMT) gene inactivation status in tumor tissue was evaluated by pyrosequencing.

RESULTS

From September 2008 to April 2020, 170 patients (84% progressive on different therapies) were consecutively treated, 114 (67%) patients received TEM-CAP and 56 (33%) TEM alone. Primary tumor sites were: pancreas 98 (58%), gastrointestinal tract 21 (12%), lung 35 (21%), and unknown 16 (9%). The ORR was 28% for the whole population (33% for TEM-CAP and 18% for TEM as single agent). The median OS (mOS) and mPFS of the whole population were 35.6 months (32.6-48.7) and 14.7 months (10.1-18.3), respectively. There were 48% PR in the MGMT hypermethylated, mainly in pancreatic NENs. Vomiting and leukopenia were the most frequent grade 3/4 toxicity.

CONCLUSIONS

This large retrospective analysis suggested that a TEM-based chemotherapy is active in advanced, pretreated NEN patients. It generated solid hypotheses that warrant a future prospective study in a biological homogeneous NEN population and clinical setting.

An algorithmic approach utilizing CK7, TTF1, beta-catenin, CDX2, and SSTR2A can help differentiate between gastrointestinal and pulmonary neuroendocrine carcinomas

Primary gastrointestinal neuroendocrine carcinoma (GI-NEC) cannot be distinguished morphologically from pulmonary neuroendocrine carcinoma (P-NEC). This can present a significant diagnostic challenge in cases where site of origin cannot be readily determined. To identify immunohistochemical (IHC) markers that can be used to reliably distinguish between GI-NECs and P-NECs, we constructed 3-mm tissue microarrays, one containing 13 GI-NECs and one containing 20 P-NECs. IHC was performed on both microarrays using 21 stains: AE1/AE3, CK7, CK20, synaptophysin, chromogranin, CD56, INSM1, SSTR2A, CDX2, SATB2, TTF1, Napsin A, PR, GATA3, PAX8, ISL1, beta-catenin, AFP, SMAD4, Rb, and p53. For GI-NEC, the most strongly expressed marker was synaptophysin (mean H-score 248), while AE1/AE3 was the most strongly expressed in P-NEC (mean H-score 230), which was stronger than in GI-NEC (p = 0.011). Other markers that were stronger overall in P-NEC than in GI-NEC included CK7 (p < 0.0001) and TTF1 (p < 0.0001). Markers that were stronger overall in GI-NEC than in P-NEC included SSTR2A (p = 0.0021), SATB2 (p = 0.018), CDX2 (p = 0.019), and beta-catenin (nuclear; p = 0.029). SMAD4, Rb, and p53 showed similar rates of abnormal protein expression. Based on these results, a stepwise algorithmic approach utilizing CK7, TTF1, beta-catenin, CDX2, and SSTR2A had a 91% overall accuracy in distinguishing these GI-NEC from P-NEC. This was tested on a second cohort of 10 metastatic GI-NEC and 10 metastatic P-NEC, with an accuracy in this cohort of 85% and an overall accuracy of 89% for the 53 cases tested. Our algorithm reasonably discriminates GI-NEC from P-NEC using currently available IHC stains.

Radical resection of large metastatic non-functioning pancreatic neuroendocrine carcinoma complicated by splenic vein thrombosis and sinistral portal hypertension

INTRODUCTION AND IMPORTANCE

There are limited reports in the literature of radical surgical resection for pancreatic neuroendocrine carcinoma (PNEC). In patients with non-functioning PNEC (NF-PNEC) within the tail of the pancreas tumours can cause splenic vein thrombosis (SVT) and subsequent sinitral portal hypertension (SPH). Radical surgical resection in such patients with concomitant liver metastasis has not previously been reported.

CASE PRESENTATION

We present a 67-year old female patient who presented with a large NF-PNEC within the tail of the pancreas with liver metastasis. We performed a distal pancreatectomy, splenectomy, partial gastrectomy and liver resection to achieve radical resecton.

DISCUSSION

All patients with NF-PNEC within the tail of the pancreatic should be considered for radical surgical resection. In the presence of multi-visceral involvement and complications such as SVT and/or SPH multi-speciality surgical expertise is likely to be required.

CONCLUSION

Radical multi-visceral resection for large NF-PNEC can be safely performed in the presence of SVT and SPH.

Post-Radiation Grade 3 Neuroendocrine Carcinoma: A New Entity?

BACKGROUND

Cancer survivors have a 14% increased risk of developing a malignancy compared with the general population. Second radiation-induced malignancies with different histologies have been described in different organs. Based on individual observations, we hypothesized that neuroendocrine carcinoma (NEC) could arise in irradiated organs.

METHODS

In a retrospective analysis of Gustave Roussy database of NEC patients (small cell lung cancer excluded) diagnosed as a second cancer, we looked for the frequency of grade 3 NEC that arose in patients who had received previous radiation therapy for a first cancer. Radiation therapy for the first cancer, dose, location of radiation therapy, pathological characteristics, overall survival, and response to treatment of secondary NEC were analyzed.

RESULTS

From January 1995 to December 2017, 847 cases of NEC were seen at Gustave Roussy. Among them, 95 (11.2%) patients had a history of previous malignancy of which 36 (4%) had been treated with radiation therapy. Out of these 36 patients, 12 (1.4% of all NEC patients) developed a NEC within the previous irradiated organ (median dose of 50 Gy, range 36-67.5). Most frequent first cancers were breast cancer (n = 4) and Hodgkin lymphoma (n = 3). NEC arose within a median time of 21.7 years (range 5.1-36.4) from radiation in the thorax (n = 5), digestive tract (n = 3), and other sites. Five large cell NEC, 3 small cell NEC, 1 mixed neuroendocrine neoplasm and 3 not otherwise specified NEC were diagnosed. Ten patients had stage IV disease at diagnosis; median overall survival was 37.8 months (95% CI [17.6 to NA]). Three patients (25%) achieved complete response with multimodal treatment.

CONCLUSIONS

NEC can arise from previously irradiated organs and may have a better outcome in this setting. Other risk factors should be investigated to explain the high rate of previous cancer in this population of neuroendocrine neoplasm.

A Consensus-Developed Morphological Re-Evaluation of 196 High-Grade Gastroenteropancreatic Neuroendocrine Neoplasms and Its Clinical Correlations

High-grade gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are classified according to morphology as well-differentiated neuroendocrine tumours (NETs) G3 or poorly differentiated neuroendocrine carcinomas (NECs). Little data exist concerning which morphological criteria this subdivision should be based on. Uncertainty exists if the NEC group should be further subdivided according to proliferation rate. Clinical data on NET G3 and NEC with a lower Ki-67 range are limited. A total of 213 patients with high-grade GEP-NEN (Ki-67 >20%) were included from the Nordic NEC Registries. Four experienced NET pathologists re-evaluated the cases to develop the best morphological criteria to separate NET G3 from NEC, assuming longer survival in NET G3. Organoid growth pattern, capillary network in direct contact to tumour cells, and absence of desmoplastic stroma were found to best separate NET G3 from NEC. Of 196 patients with metastatic disease, NET G3 was found in 12.3%, NEC with a Ki-67 <55% (NEC < 55) in 29.6%, and NEC with a Ki-67 ≥55% (NEC ≥ 55) in 56.6%. Only in 1.5%, the morphology was ambiguous. Of 164 patients receiving first-line chemotherapy, 88% received platinum/etoposide treatment. Response rate was higher for NEC ≥ 55 (44%) than that of NEC < 55 (25%) and NET G3 (24%) (p = 0.025 and p = 0.026). Median progression-free survival was 5 months for all groups. Median overall survival was 33 months for NET G3 compared to 11 months for both NEC < 55 and NEC ≥ 55 (p = 0.004 and 0.003). Specific morphological criteria can separate NET G3 from NECs and show prognostic significance. High-grade GEP-NEN patients stratified by morphology and proliferation rate demonstrate significant differences in response to chemotherapy and survival.

Clinicopathological and genomic features in patients with head and neck neuroendocrine carcinoma

Neuroendocrine carcinoma (NEC) of the head and neck is a rare type of malignancy, accounting for only 0.3% of all head and neck cancers, and its clinicopathological and genomic features have not been fully characterized. We conducted a retrospective analysis of 27 patients with poorly differentiated NEC of the head and neck seen at our institution over a period of 15 years. Patient characteristics, adopted therapies, and clinical outcomes were reviewed based on the medical records. Pathological analysis and targeted sequencing of 523 cancer-related genes were performed using evaluable biopsied/resected specimens based on the clinical data. The most common tumor locations were the paranasal sinus (33%) and the oropharynx (19%). Eighty-one percent of the patients had locally advanced disease. The 3-year overall survival rates in all patients and in the 17 patients with locally advanced disease who received multimodal curative treatments were 39% and 53%, respectively. Histologically, large cell neuroendocrine carcinoma was the predominant subtype (58% of evaluable cases), and the Ki-67 labeling index ranged from 59 to 99% (median: 85%). Next-generation sequencing in 14 patients identified pathogenic/likely pathogenic variants in TP53, RB1, PIK3CA-related genes (PREX2, PIK3CA, and PTEN), NOTCH1, and SMARCA4 in six (43%), three (21%), two (14%), two (14%), and one (7%) patients, respectively. Sequencing also detected the FGFR3-TACC3 fusion gene in one patient. The median value of the total mutational burden (TMB) was 7.1/Mb, and three patients had TMB ≥ 10. Regardless of the aggressive pathological features, our data revealed favorable clinical characteristics in the patients with locally advanced disease who received curative treatment. The lower TP53 and RB1 mutation prevalence rates compared to those described for small cell lung cancer suggests the biological heterogeneity of NEC in different parts of the body. Furthermore, the FGFR3-TACC3 fusion gene and mutations in genes encoding the components of the NOTCH and PI3K/AKT/mTOR pathways found in our study may be promising targets for NEC of the head and neck.

Mixed epithelial endocrine neoplasms of the colon and rectum - An evolution over time: A systematic review

BACKGROUND

Mixed tumors of the colon and rectum, composed of a combination of epithelial and endocrine elements of benign and malignant potential are rare neoplasms. These can occur anywhere in the gastrointestinal tract and are often diagnosed incidentally. Though they have been a well-documented entity in the pancreas, where the exocrine-endocrine mixed tumors have been known for a while, recognition and accurate diagnosis of these tumors in the colon and rectum, to date, remains a challenge. This is further compounded by the different terminologies that have been attributed to these lesions over the years adding to increased confusion and misclassification. Therefore, dedicated literature reviews of these lesions in the colon and rectum are inconsistent and are predominantly limited to case reports and case series of limited case numbers. Though, most of these tumors are high grade and of advanced stage, intermediate and low grade lesions of these mixed tumors are also increasingly been reported. There are no established independent consensus based guidelines for the therapeutic patient management of these unique lesions.

AIM

To provide a comprehensive targeted literature review of these complex mixed tumors in the colon and rectum that chronicles the evolution over time with summarization of historical perspectives of terminology and to further our understanding regarding their pathogenesis including genomic landscape, clinicoradiological features, pathology, treatment, prognosis, the current status of the management of the primary lesions, their recurrences and metastases.

METHODS

A comprehensive review of the published English literature was conducted using the search engines PubMed, MEDLINE and GOOGLE scholar. The following search terms ["mixed tumors colon" OR mixed endocrine/neuroendocrine tumor/neoplasm/lesion colon OR adenocarcinoma and endocrine/neuroendocrine tumor colon OR mixed adenocarcinoma and endocrine/neuroendocrine carcinoma colon OR Amphicrine tumors OR Collision tumors] were used. Eligibility criteria were defined and all potential relevant items, including full articles and/or abstracts were independently reviewed, assessed and agreed upon items were selected for in-depth analysis.

RESULTS

In total 237 full articles/abstracts documents were considered for eligibility of which 45 articles were illegible resulting in a total of 192 articles that were assessed for eligibility of which 139 have been selected for reference in this current review. This seminal manuscript is a one stop article that provides a detailed outlook on the evolution over time with summarization of historical perspectives, nomenclature, clinicoradiological features, pathology, treatment, prognosis and the current status of the management of both the primary lesions, their recurrences and metastases. Gaps in knowledge have also been identified and discussed. An important outcome of this manuscript is the justified proposal for a new, simple, clinically relevant, non-ambiguous terminology for these lesions to be referred to as mixed epithelial endocrine neoplasms (MEENs).

CONCLUSION

MEEN of the colon and rectum are poorly understood rare entities that encompass an extensive range of heterogeneous tumors with a wide variety of combinations leading to tumors of high, intermediate or low grade malignant potential. This proposed new revised terminology of MEEN will solve the biggest hurdle of confusion and misclassification that plagues these rare unique colorectal neoplasms thus facilitating the future design of multi institutional prospective randomized controlled clinical trials to develop and evaluate newer therapeutic strategies that are recommended for continued improved understanding and personal optimization of clinical management of these unique colorectal neoplasms.

Well Differentiated Grade 3 Neuroendocrine Tumors of the Digestive Tract: A Narrative Review

The 2017 World Health Organization (WHO) classification of neuroendocrine neoplasms (NEN) of the digestive tract introduced a new category of tumors named well-differentiated grade 3 neuroendocrine tumors (NET G-3). These lesions show a number of mitosis, or a Ki-67 index higher than 20% with a well-differentiated morphology, therefore separating them from neuroendocrine carcinomas (NEC) which are poorly differentiated. It has become clear that NET G-3 show differences not only in morphology but also in genotype, clinical presentation, and treatment response. The incidence of digestive NET G-3 represents about one third of NEN G-3 with main tumor sites being the pancreas, the stomach and the colon. Treatment for NET G-3 is not yet standardized because of lack of data. In a non-metastatic setting, international guidelines recommend surgical resection, regardless of tumor grading. For metastatic lesion, chemotherapy is the main treatment with similar regimen as NET G-2. Sunitinib has also shown some positive results in a small sample of patients but this needs confirmation. Peptide receptor radionuclide therapy (PRRT) and immunotherapy could be future available treatments after ongoing studies. The goal of this review was to sum up the latest data on the epidemiology and management of digestive NET G-3.

Post first-line dacarbazine or temozolomide in neuroendocrine carcinoma

OBJECTIVE

First-line chemotherapy in metastatic neuroendocrine carcinomas (NECs) is based on etoposide and platinum. However, there is no standard concerning second-line treatment. The objective of this study was to evaluate efficacy and tolerance of dacarbazine or temozolomide in metastatic digestive NEC as post first-line treatment.

MATERIAL AND METHODS

This study included patients with a metastatic NEC of digestive or unknown primary site. All patients received platinum-etoposide as first-line chemotherapy. Primary endpoint was progression-free survival (PFS). Secondary endpoints were clinical/morphological responses, toxicity, and overall survival (OS).

RESULTS

Twenty-seven patients were included: 17 received dacarbazine and 10 temozolomide as post-first line treatments. Median PFS was 3.0 (95%CI (2.2;3.7)) months. There was no significant difference between dacarbazine and temozolomide on PFS. Clinical and morphological responses were found in 12 and 9 patients, respectively. Median OS was 7.2 (95%CI (2.2;12.2)) months. The toxicity profile was that expected with such treatments.

CONCLUSION

LV5FU2-dacarbazine or temozolomide-capecitabine chemotherapies allow a temporary clinical response for almost half of patients and/or a morphological response for a third of patients.

Digestive Neuroendocrine Neoplasms (NEN): French Intergroup clinical practice guidelines for diagnosis, treatment and follow-up (SNFGE, GTE, RENATEN, TENPATH, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, SFR)

INTRODUCTION

This document is a summary of the French Intergroup guidelines regarding the management of digestive neuroendocrine neoplasms (NEN) published in February 2020 (www.tncd.org).

METHODS

All French medical societies involved in the management of NEN took part in this work. Recommendations were graded into four categories (A, B, C or D), according to the level of evidence found in the literature until May 2019.

RESULTS

The management of NEN is challenging because of their heterogeneity and the increasing complexity of diagnostic and therapeutic procedures. Pathological analysis is required for their diagnostic and prognostic characterization, which mainly relies on differentiation, grade and stage. The two main emergency situations are functioning syndromes and poorly-differentiated carcinoma. Chromogranin A is the main biochemical marker of NET, although of limited clinical interest. Initial characterization relies on morphological and isotopic imaging. The treatment of localized NET relies on watchful follow-up and local or surgical resection depending on its supposed aggressiveness. Treatment options for metastatic disease include surgery, somatostatin analogues, chemotherapy, targeted therapies, organ-driven locoregional therapies and peptide-receptor radionuclide therapy. As specific predictive factors of treatment efficacy are yet to be identified and head-to-head comparisons have not or only rarely been performed, the therapeutic strategy currently depends on prognostic factors. Cumulative toxicity and the impact of treatment on quality of life must be considered since survival is relatively long in most patients with NET.

CONCLUSION

These guidelines are proposed to achieve the most beneficial therapeutic strategy in clinical practice as the therapeutic landscape of NEN is becoming ever more complex. These recommendations are permanently being reviewed.

Efficacy of Second-Line Chemotherapy in Extrapulmonary Neuroendocrine Carcinoma

OBJECTIVES

A platinum/etoposide doublet is standard first-line therapy for poorly differentiated neuroendocrine carcinoma (PD NEC); however, evidence to guide treatment beyond first-line regimens is lacking. This study aimed to evaluate the efficacy of second-line regimens in PD NEC.

METHODS

We performed a retrospective analysis of patients treated with second-line chemotherapy for PD NEC. Inclusion criteria were previous first-line therapy with platinum/etoposide, extrapulmonary PD NEC, and follow-up data. The primary end points were overall survival (OS) and progression-free survival (PFS) after second-line therapy. Secondary end points included OS and PFS from first-line therapy.

RESULTS

Sixty-four patients were included. The median OS from initiation of second-line therapy was 6.2 months (95% confidence interval [CI], 4.9-8.9). The median PFS was 2.3 months (95% CI, 2.0-3.2). No second-line regimen showed a statistically significant difference in OS or PFS. There was a significant increase in OS for cisplatin first-line regimens compared with carboplatin (17.0 months [95% CI, 12.5-22.6] vs 11.7 months [95% CI, 8.0-14.0]).

CONCLUSIONS

The efficacy of current second-line therapy in PD NEC is poor. No second-line regimen showed statistically significant superiority. Cisplatin was associated with longer OS regardless of second-line regimen or age. However, unmeasured confounders such as performance status or comorbidities may explain this effect.

P53, Somatostatin receptor 2a and Chromogranin A immunostaining as prognostic markers in high grade gastroenteropancreatic neuroendocrine neoplasms

Background

High grade gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN) with a Ki67 proliferation index > 20%, include well-differentiated tumours grade 3 (NET G3) and poorly differentiated (PD) neuroendocrine carcinomas (NEC). Abnormal p53-expression is a feature of PD tumours, while expression of chromogranin A (CgA) and somatostatin-receptor 2a (SSTR-2a) may be a feature of well-differentiated tumours. The aim of this study was to elucidate the expression and prognostic value of these three markers in 163 GEP-NEN patients with a Ki67-index > 20%.

Method

Clinical data, histopathology and overall survival were analysed according to Kaplan-Meier’s method and Cox regression. The expression of SSTR-2a, CgA and synaptophysin was analysed in tumour specimens by immunohistochemistry, and semi-quantitatively scored as negative (< 5%), heterogeneously positive (5–30%) or strongly positive (> 30%). P53 was defined as normal when scored as heterogeneously positive (1–30%), and abnormal when negative (0%) or strongly positive (> 30%).

Results

In multivariate analysis, better survival was observed among patients with heterogeneously positive p53 compared to strongly positive (p < 0.001). When dichotomised, tumours with a heterogeneously positive p53 vs. negative and strongly positive p53 also showed a significantly better survival (p = 0.002).

Survival was significantly worse for negative CgA compared to heterogeneously positive CgA (p = 0.02). Strongly positive SSTR-2a expression was found in 26% of the 163 included patients. Well-differentiated morphology correlated with strong expression of SSTR-2a and CgA, and heterogeneously positive p53-staining, and was more frequent in pancreatic primaries. In pancreatic primaries, strongly positive SSTR-2a was associated with longer survival (univariate analysis, p = 0.02). A significantly lower Ki67 proliferation index was found in patients with a heterogeneously positive p53, a positive SSTR-2a and CgA expression.

Conclusion

Our results suggest that abnormal p53-expression is an independent negative prognostic marker in GEP-NEN with a Ki67-index > 20%. Patients with heterogeneously positive p53 had the best prognosis. SSTR-2a was a positive prognostic marker in pancreatic NEN. Negative CgA was associated with a significantly worse OS compared to heterogeneously positive CgA-expression in a multivariate sub-analysis. Lower Ki67 index correlated significantly with heterogeneously positive p53, positive SSTR-2a and CgA expression.

Retrospective study on mixed neuroendocrine non-neuroendocrine neoplasms from five European centres

BACKGROUND

Mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) is a rare diagnosis, mainly encountered in the gastro-entero-pancreatic tract. There is limited knowledge of its epidemiology, prognosis and biology, and the best management for affected patients is still to be defined.

AIM

To investigate clinical-pathological characteristics, treatment modalities and survival outcomes of a retrospective cohort of patients with a diagnosis of MiNEN.

METHODS

Consecutive patients with a histologically proven diagnosis of MiNEN were identified at 5 European centres. Patient data were retrospectively collected from medical records. Pathological samples were reviewed to ascertain compliance with the 2017 World Health Organisation definition of MiNEN. Tumour responses to systemic treatment were assessed according to the Response Evaluation Criteria in Solid Tumours 1.1. Kaplan-Meier analysis was applied to estimate survival outcomes. Associations between clinical-pathological characteristics and survival outcomes were explored using Log-rank test for equality of survivors functions (univariate) and Cox-regression analysis (multivariable).

RESULTS

Sixty-nine consecutive patients identified; Median age at diagnosis: 64 years. Males: 63.8%. Localised disease (curable): 53.6%. Commonest sites of origin: colon-rectum (43.5%) and oesophagus/oesophagogastric junction (15.9%). The neuroendocrine component was; predominant in 58.6%, poorly differentiated in 86.3%, and large cell in 81.25%, of cases analysed. Most distant metastases analysed (73.4%) were occupied only by a poorly differentiated neuroendocrine component. Ninety-four percent of patients with localised disease underwent curative surgery; 53% also received perioperative treatment, most often in line with protocols for adenocarcinomas from the same sites of origin. Chemotherapy was offered to most patients (68.1%) with advanced disease, and followed protocols for pure neuroendocrine carcinomas or adenocarcinomas in equal proportion. In localised cases, median recurrence free survival (RFS); 14.0 months (95%CI: 9.2-24.4), and median overall survival (OS): 28.6 months (95%CI: 18.3-41.1). On univariate analysis, receipt of perioperative treatment (vs surgery alone) did not improve RFS (P = 0.375), or OS (P = 0.240). In advanced cases, median progression free survival (PFS); 5.6 months (95%CI: 4.4-7.4), and median OS; 9.0 months (95%CI: 5.2-13.4). On univariate analysis, receipt of palliative active treatment (vs best supportive care) prolonged PFS and OS (both, P < 0.001).

CONCLUSION

MiNEN is most commonly driven by a poorly differentiated neuroendocrine component, and has poor prognosis. Advances in its biological understanding are needed to identify effective treatments and improve patient outcomes.

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.

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.

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.

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.

Evaluating bevacizumab in combination with FOLFIRI after the failure of platinum-etoposide regimen in patients with advanced poorly differentiated neuroendocrine carcinoma: The PRODIGE 41-BEVANEC randomized phase II study

INTRODUCTION

Patients with gastroenteropancreatic (GEP), metastatic or locally advanced, non-resectable, grade 3 poorly-differentiated neuroendocrine carcinoma (NEC) are treated with cisplatin (or carboplatin)-etoposide in first-line palliative chemotherapy (CT1). However, nearly all patients will develop resistance and there is no standard second-line treatment.

AIM

PRODIGE 41-BEVANEC is an academic randomized, phase II study designed to evaluate the efficacy of bevacizumab in combination with FOLFIRI after failure of CT1 in unknown primary NEC and GEP-NEC.

MATERIALS AND METHODS

The main eligibility criteria are age ≥18 years, metastatic (synchronous or metachronous) or locally advanced, non-resectable, grade 3 GEP-NEC, and documented progressive disease during or after CT1 therapy.

RESULTS

A total of 124 patients will be randomly assigned (1:1) to receive either 5 mg/kg bevacizumab with FOLFIRI, or FOLFIRI alone, every 14 days until disease progression or unacceptable toxicity. The hypothesis is to demonstrate a 6-month overall survival for at least 50% of the patients in bevacizumab arm versus 35% in the control arm (FOLFIRI alone). Secondary endpoints are objective response, response duration, progression-free survival, toxicity, and biochemical response.

CONCLUSION

The study is currently opened in France (NCT02820857). The first patient was randomized on September 6, 2017.