Intravenous versus oral etoposide: efficacy and correlation to clinical outcome in patients with high-grade metastatic gastroenteropancreatic neuroendocrine neoplasms (WHO G3)

Selection of Chemotherapy in Advanced Poorly Differentiated Extra-Pulmonary Neuroendocrine Carcinoma

Extra-pulmonary poorly differentiated neuroendocrine carcinoma is rare, and evidence for treatment has been limited. In this article, the evidence behind the cytotoxic chemotherapy choices used for metastatic or unresectable EP-PD-NEC is reviewed. In the first-line setting, etoposide and platinum chemotherapy or irinotecan and platinum have been demonstrated to be equivalent in a large phase III trial. Questions remain regarding the optimal number of cycles, mode of delivery, and the precise definition of platinum resistance in this setting. In the second-line setting, FOLFIRI has emerged as an option, with randomized phase 2 trials demonstrating modest, but significant, response rates. Beyond this, data are extremely limited, and several regimens have been used. Heterogeneity in biological behaviour is a major barrier to optimal EP-PD-NEC management. Available data support the potential role of the Ki-67 index as a predictive biomarker for chemotherapy response. A more personalised approach to management in future studies will be essential, and comprehensive multi-omic approaches are required to understand tumour somatic genetic changes in relation to their effects on the surrounding microenvironment.

Decoding Diffuse Midline Gliomas: A Comprehensive Review of Pathogenesis, Diagnosis and Treatment

Diffuse midline gliomas (DMGs) are a group of aggressive CNS tumors, primarily affecting children and young adults, which have historically been associated with dismal outcomes. As the name implies, they arise in midline structures in the CNS, primarily in the thalamus, brainstem, and spinal cord. In more recent years, significant advances have been made in our understanding of DMGs, including molecular features, with the identification of potential therapeutic targets. We aim to provide an overview of the most recent updates in the field of DMGs, including classification, molecular subtypes, diagnostic techniques, and emerging therapeutic strategies including a review of the ongoing clinical trials, thus providing the treating multidisciplinary team with a comprehensive understanding of the current landscape and potential therapeutic strategies for this devastating group of tumors.

Potent molecular-targeted therapies for gastro-entero-pancreatic neuroendocrine carcinoma

Neuroendocrine neoplasms (NENs), which are characterized by neuroendocrine differentiation, can arise in various organs. NENs have been divided into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs) based on morphological differentiation, each of which has a distinct etiology, molecular profile, and clinicopathological features. While the majority of NECs originate in the pulmonary organs, extrapulmonary NECs occur most predominantly in the gastro-entero-pancreatic (GEP) system. Although platinum-based chemotherapy is the main therapeutic option for recurrent or metastatic GEP-NEC patients, the clinical benefits are limited and associated with a poor prognosis, indicating the clinically urgent need for effective therapeutic agents. The clinical development of molecular-targeted therapies has been hampered due to the rarity of GEP-NECs and the paucity of knowledge on their biology. In this review, we summarize the biology, current treatments, and molecular profiles of GEP-NECs based on the findings of pivotal comprehensive molecular analyses; we also highlight potent therapeutic targets for future precision medicine based on the most recent results of clinical trials.

European Neuroendocrine Tumor Society (ENETS) 2023 guidance paper for digestive neuroendocrine carcinoma

This ENETS guidance paper, developed by a multidisciplinary working group, provides up-to-date and practical advice on the diagnosis and management of digestive neuroendocrine carcinoma, based on recent developments and study results. These recommendations aim to pave the road for more standardized care for our patients resulting in improved outcomes. Prognosis is generally poor for digestive NEC, most are advanced at diagnosis and median survival in metastatic disease is 11-12 months. Surgery can be of benefit for localized disease after extensive preoperative imaging. Carboplatin in combination with etoposide is recommended as first-line treatment for metastatic disease. Irinotecan with fluoropyrimidines has the best evidence as second-line treatment. Immunotherapy plays a minor role in biomarker-unselected patients. Molecular profiling if available is encouraged to identify new targets. More prospective clinical trials are highly needed to fulfil the unmet needs in this field, especially on new predictive and prognostic biomarkers and to improve survival of patients with advanced disease.

Therapeutic strategies for gastroenteropancreatic neuroendocrine neoplasms: State-of-the-art and future perspectives

Although gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have always been considered rare tumors, their incidence has risen over the past few decades. They represent a highly heterogeneous group of neoplasms with several prognostic factors, including disease stage, proliferative index (Ki67), and tumor differentiation. Most of these neoplasms express somatostatin receptors on the cell surface, a feature that has important implications in terms of prognosis, diagnosis, and therapy. Although International Guidelines propose algorithms aimed at guiding therapeutic strategies, GEP-NEN patients are still very different from one another, and the need for personalized treatment continues to increase. Radical surgery is always the best option when feasible; however, up to 80% of cases are metastatic upon diagnosis. Regarding medical treatments, as GEP-NENs are characterized by relatively long overall survival, multiple therapy lines are adopted during the lifetime of these patients, but the optimum sequence to be followed has never been clearly defined. Furthermore, although new molecular markers aimed at predicting the response to therapy, as well as prognostic scores, are currently being studied, their application is still far from being part of daily clinical practice. As they represent a complex disease, with therapeutic protocols that are not completely standardized, GEP-NENs require a multidisciplinary approach. This review will provide an overview of the available therapeutic options for GEP-NENs and attempts to clarify the possible approaches for the management of these patients and to discuss future perspectives in this field.

The Novel Dual Topoisomerase Inhibitor P8-D6 Shows Anti-myeloma Activity In Vitro and In Vivo

P8-D6 is a novel dual inhibitor of human topoisomerase I (TOP1) and II (TOP2) with broad pro-apoptotic antitumor activity. NCI-60 screening revealed markedly improved cytotoxicity of P8-D6 against solid and leukemia cell lines compared with other single and dual topoisomerase inhibitors, for example, irinotecan, doxorubicin, or pyrazoloacridine. In this study, we investigated the capacity of P8-D6 to inhibit myeloma cell growth in vitro and in vivo Growth inhibition assays demonstrated significant anti-myeloma effects against different myeloma cell lines with IC₅₀ values in the low nanomolar range. Freshly isolated plasma cells of patients with multiple myeloma were killed by P8-D6 with similar doses. P8-D6 activated caspase 3/7 and induced significant apoptosis of myeloma cells. Supportive effects of bone marrow stromal cells on IL6-dependent INA-6 myeloma cells were abrogated by P8-D6 and apoptosis occurred in a time- and dose-dependent manner. Of note, healthy donor peripheral blood mononuclear cells and human umbilical vein endothelial cells were not affected at concentrations toxic for malignant plasma cells. Treatment of myeloma xenografts in immunodeficient SCID/beige mice by intravenous and, notably, also oral application of P8-D6 markedly inhibited tumor growths, and significantly prolonged survival of tumor-bearing mice.

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.

Prognostic factors of metastatic neuroendocrine carcinoma under first-line treatment with platinum etoposide with a focus on NEC score and Rb expression: Results from the multicentre RBNEC study of the Groupe d'Etude des Tumeurs Endocrines (GTE) and the ENDOCAN-RENATEN network

INTRODUCTION AND AIM

Neuroendocrine carcinomas (NECs) are aggressive malignant diseases. Platinum-etoposide (PE) combination is the standard first-line treatment, whatever the primary location. The NEC score and also retinoblastoma protein (Rb) status have been suggested to be predictive/prognostic factors in NEC. The primary objective of our multicentric retrospective study was to evaluate the prognostic relevance of the NEC score and Rb status, assessed by immunohistochemistry in PE-treated patients with metastatic NEC.

METHODS

Seven centres participated. The inclusion criteria were NEC, whatever the primary site, metastatic stage, first-line treatment with PE and tissue samples available. Rb status was determined centrally.

RESULTS

We report multicentric data from 185 metastatic patients (37% women, median age 63). There were 108 small-cell NECs (SCNECs, 58.4%), 50 large-cell NECs (LCNECs, 27%) and 27 not otherwise specified NECs (nosNECs, 14.6%). The primary sites were the thorax (37%), gastroenteropancreatic sites (38%), unknown (15%) and other (9%). The mean Ki-67 index was 76% (range 20-100). Rb status was interpretable in 122 cases. Rb expression was lost in 74% of the cases: 84% of SCNEC vs. 60% and 63% of LCNEC and nosNEC, respectively (p = 0.016). Objective response was seen in 70% of SCNEC, 45% of LCNEC and 48% of nosNEC (p < 0.001) and in 62% of Rb-negative tumours vs. 46% of Rb-positive tumours (p = 0.3). There was no difference in median progression-free survival or overall survival (OS) as per Rb status. Age, NEC score and response to chemotherapy were the main factors associated with OS in our cohort.

CONCLUSION

In our series, Rb status had no prognostic impact in PE-treated metastatic patients with NEC, whereas age, NEC score and response to chemotherapy were the main factors associated with OS.

Efficacy of a third-generation oncolytic herpes simplex virus in neuroendocrine tumor xenograft models

BACKGROUND: Few chemotherapies are available for neuroendocrine tumors, especially for highly malignant neuroendocrine cancers. The third-generation oncolytic herpes simplex virus type 1 (HSV-1) T-01 selectively replicates in tumor cells and shows cytotoxicity against tumor cells without damaging surrounding normal tissues. We examined the antitumor effect of T-01 to explore novel treatments for patients with neuroendocrine tumors.

METHODS: The cytotoxicity of T-01 was tested in two human and one murine neuroendocrine tumor cell lines in vitro. Mouse models with subcutaneously implanted human neuroendocrine tumor QGP1 cells were used to investigate T-01 efficacy in vivo.

RESULTS: T-01 showed cytotoxicity against the three cell lines in vitro. In xenograft models, the growth of tumors derived from QGP1 cells was inhibited by T-01 compared with control group. Although weight loss of mice was observed with tumor growth in the control group, it was suppressed by T-01 administration. The antitumor effects of T-01 were dependent on virus concentration and frequency of administration.

CONCLUSIONS: T-01 effectively inhibits tumor cell proliferation in a poorly differentiated NEC mouse model. These results suggest that the third-generation oncolytic HSV-1 may serve as a novel treatment for patients with neuroendocrine tumors.

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.

Urgent need for consensus: international survey of clinical practice exploring use of platinum-etoposide chemotherapy for advanced extra-pulmonary high grade neuroendocrine carcinoma (EP-G3-NEC)

BACKGROUND

Platinum-etoposide (PE) chemotherapy (CH) is a globally established combination for extra-pulmonary high grade neuroendocrine carcinoma (EP-G3-NEC); the optimal schedule has not been established.

METHODS

An international survey was designed, and completed by clinicians with an expertise in the field to assess consistency in clinical practice.

RESULTS

Seventy-five replies were received (June-Nov'17). A minority of physicians (13; 17.6%) did not take Ki-67 or morphology (9; 12.0%) into consideration for selection of CH. Most (72; 96.0%) selected PE-CH as first-line treatment for EP-G3-NEC. CH schedules varied: cisplatin-based (37/71; 52.1%), carboplatin-based (34/71; 47.9%); intravenous etoposide (64/71; 90.1%), oral etoposide (7/71; 9.9%). Choice of second-line CH depended on time to progression on PE-based first-line: if > 6 months, re-challenge with PE was the preferred choice (34; 45.9%); if < 6 months, alternative combinations such as fluoropyrimidine/irinotecan (21; 29.2%) or temozolomide/capecitabine (22; 30.6%) were used.

CONCLUSION

Significant variation in PE regimen employed exists. Standardising clinical practice would facilitate clinical trial development.