Predictive and prognostic factors for treatment and survival in 305 patients with advanced gastrointestinal neuroendocrine carcinoma (WHO G3): the NORDIC NEC study

An Italian real-world multicenter study of patients with advanced mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) of the gastro-entero-pancreatic system treated with chemotherapy

PURPOSE

The aim of this study is to describe the clinical management of an Italian series of patients with advanced gastro-entero-pancreatic (GEP) MiNENs treated in clinical practice.

METHODS

Clinical records of patients from four Italian referral Centers were retrospectively analyzed to correlate clinical/biological data with clinical outcomes. All the surgical specimens were centrally reviewed.

RESULTS

Clinical data and surgical samples of 51 patients during 1995-2015 were analyzed. Sites of origin were: 32 colorectal, 14 gastro-esophageal, and 5 pancreatobiliary. Twenty-one out of fifty-one (42.2%) developed metachronous distant metastases. Only 5/51 (9.8%) patients received peri-operative therapy, and 23/51 (45.1%) first-line chemotherapy, mostly fluoropyrimidines/oxaliplatin. The NEN component was poorly differentiated in the whole population. Patients with Ki67 index < 55% in the NEC component had a significantly longer median overall survival (OS) (35.3 months; 95% CI 27.1-41.0) than those with Ki67 ≥ 55% (11.9 months; 95% CI 9.1-14.0) P = 0.0005. The median OS was 14 months (95% CI 10.1-19.1) in the whole cohort, with 11.4 months (95% CI 6.2-20.2) in patients who received a first-line therapy.

CONCLUSION

This study confirms that GEP-MiNENs represent a complex disease and that over the past years the clinical management has been predominantly guided by the subjective judgment of the clinicians. Although, in this series, the NEC component appeared mostly responsible for the systemic spread and prognosis on the whole neoplasm, the lack of strong prognostic and predictive factors universally recognized seems to condition their management so far. Future prospective clinical and biomolecular studies could help clinicians to improve clinical management of GEP-MiNENs.

Treatment outcome according to genetic tumour alterations and clinical characteristics in digestive high-grade neuroendocrine neoplasms

BACKGROUND

Chemotherapy has limited efficacy in advanced digestive high-grade neuroendocrine neoplasms (HG-NEN) and prognosis is dismal. Predictive markers for palliative chemotherapy are lacking, and prognostic markers are limited.

METHODS

Digestive HG-NEN patients (n = 229) were prospectively included 2013-2017. Pathological re-assessment revealed 188 neuroendocrine carcinomas (NEC) and 41 neuroendocrine tumours (NET G3). Tumour-DNA was sequenced across 360 cancer-related genes, assessing mutations (mut) and copy number alterations. We linked sequencing results to clinical information and explored potential markers for first-line chemotherapy efficacy and survival.

RESULTS

In NEC given cis/carboplatin and etoposide (PE), TP53mut predicted inferior response rate in multivariate analyses (p = 0.009) and no BRAFmut NEC showed response. In overall assessment of PE-treated NEC, no genetic alterations were prognostic for OS. For small-cell NEC, TP53mut were associated with longer OS (p = 0.011) and RB1 deletions predicted lack of immediate-progression (p = 0.003). In non-small cell NEC, APC mut were associated with immediate-progression and shorter PFS (p = 0.008/p = 0.004). For NET G3, ATRXmut, ARID1A- and ERS1 deletions were associated with shorter PFS.

CONCLUSION

Correlations between genetic alterations and response/immediate-progression to PE were frequent in NEC but affected PFS or OS only when subdividing for cell-type. The classification of digestive NEC into large- and small-cell seems therefore molecularly and clinically relevant.

A randomized phase II trial of Captem or Folfiri as second-line therapy in neuroendocrine carcinomas

BACKGROUND

Neuroendocrine Carcinomas (NECs) prognosis is poor.No standard second-line therapy is currently recognized after failure of platinum-based first-line treatment. FOLFIRI and CAPTEM regimens have shown promising activity in preliminary studies. We aimed to evaluate these regimens in metastatic NEC patients.

METHODS

This is an open-label, multicenter, randomized non-comparative phase II trial to evaluate the activity and safety of FOLFIRI or CAPTEM in metastatic NEC patients. Primary endpoints were the 12 weeks-Disease Control Rate (12w-DCR) by investigator assessment per RECIST v1.1 and safety per CTCAE v5.0. Additional endpoints included overall response rate (ORR), progression-free survival (PFS) and overall survival (OS). Patients' serum samples were subject to NGS miRNome profiling in comparison with healthy donors to reveal differentially expressed miRNAs as candidate circulating biomarkers.

RESULTS

The study was halted for futility at interim analysis, as the minimum 12w-DCR threshold of 10 out of 25 patients required for the first step was not reached. From 06/03/2017 to 18/01/2021, 53 out of 112 patients were enrolled. Median follow-up was 22.6 months (range: 1.4-60.4). The 12w-DCR was 39.1 % in the FOLFIRI arm and 28.0 % in the CAPTEM arm. In the FOLFIRI subgroup the 12-months OS rate was 28.4 % (95 % CI: 12.7-46.5) while in the CAPTEM subgroup it was 32.4 % (95 % CI: 14.9-51.3). The most common G3-G4 side effects were neutropenia (n = 5, 18.5 %) and anemia (n = 2, 7.4 %) for FOLFIRI and G3-G4 thrombocytopenia (n = 2, 8.0 %), G4 nausea/vomiting (n = 1, 4.0 %) for CAPTEM. Three microRNAs emerged as NEC independent predictors. High expression values were found to be significantly associated with decreased PFS and OS.

CONCLUSION

The safety profile of FOLFIRI and CAPTEM was manageable. FOLFIRI and CAPTEM chemotherapy showed comparable activity in the second-line setting after progression on etoposide/platinum.

CLINICALTRIALS

GOV IDENTIFIER

NCT03387592.

Mixed hepatocellular carcinoma and high-grade neuroendocrine neoplasm with ambiguous histopathological features: a case report

Well-differentiated neuroendocrine tumor (NET) and poorly differentiated neuroendocrine carcinoma (NEC) are distinct entities with different biological behavior. However, difficult cases showing equivocal morphology have been reported in some organs. Herein, we report a case of primary hepatic neuroendocrine neoplasm (NEN) with ambiguous histopathological features admixed with conventional hepatocellular carcinoma (HCC). A 70-year-old man with untreated chronic hepatitis B underwent left medial sectionectomy because of two incidental liver masses. On pathological examination, one of the resected tumors had intermingling NEN and HCC components. The NEN component consisted of relatively uniform tumor cells proliferating in trabecular, cord-like, or solid patterns with peripheral nuclear palisading. The tumor cells were immunopositive for synaptophysin, chromogranin A, cluster of differentiation 56 (CD56), and focally hepatocyte paraffin 1. p53 showed wild-type expression. The Ki-67 labeling index was 27% at the hot spot. Eleven months after the surgery, he died of a cerebral hemorrhage without evidence of recurrent liver cancer. The intermediate degree of differentiation and the modest proliferative activity can challenge the distinction between NEC and NET G3. While the coexisting HCC indicates NEC rather than NET in a pathogenetic viewpoint, such ambiguous tumor may not be as aggressive as typical NECs.

Nivolumab plus platinum-doublet chemotherapy in treatment-naive patients with advanced grade 3 Neuroendocrine Neoplasms of gastroenteropancreatic or unknown origin: The multicenter phase 2 NICE-NEC trial (GETNE-T1913)

The prognosis of patients with advanced high-grade (G3) digestive neuroendocrine neoplasms (NENs) is rather poor. The addition of immune checkpoint inhibition to platinum-based chemotherapy may improve survival. NICE-NEC (NCT03980925) is a single-arm, phase II trial that recruited chemotherapy-naive, unresectable advanced or metastatic G3 NENs of gastroenteropancreatic (GEP) or unknown origin. Patients received nivolumab 360 mg intravenously (iv) on day 1, carboplatin AUC 5 iv on day 1, and etoposide 100 mg/m2/d iv on days 1-3, every 3 weeks for up to six cycles, followed by nivolumab 480 mg every 4 weeks for up to 24 months, disease progression, death or unacceptable toxicity. The primary endpoint was the 12-month overall survival (OS) rate (H0 50%, H1 72%, β 80%, α 5%). Secondary endpoints were objective response rate (ORR), duration of response (DoR), progression-free survival (PFS), and safety. From 2019 to 2021, 37 patients were enrolled. The most common primary sites were the pancreas (37.8%), stomach (16.2%) and colon (10.8%). Twenty-five patients (67.6%) were poorly differentiated carcinomas (NECs) and/or had a Ki67 index >55%. The ORR was 56.8%. Median PFS was 5.7 months (95%CI: 5.1-9) and median OS 13.9 months (95%CI: 8.3-Not reached), with a 12-month OS rate of 54.1% (95%CI: 40.2-72.8) that did not meet the primary endpoint. However, 37.6% of patients were long-term survivors (>2 years). The safety profile was consistent with previous reports. There was one treatment-related death. Nivolumab plus platinum-based chemotherapy was associated with prolonged survival in over one-third of chemonaïve patients with G3 GEP-NENs, with a manageable safety profile.

An Overview of Altered Pathways Associated with Sensitivity to Platinum-Based Chemotherapy in Neuroendocrine Tumors: Strengths and Prospects

Neuroendocrine neoplasms (NENs) are a diverse group of malignancies with a shared phenotype but varying prognosis and response to current treatments. Based on their morphological features and rate of proliferation, NENs can be classified into two main groups with a distinct clinical behavior and response to treatment: (i) well-differentiated neuroendocrine tumors (NETs) or carcinoids (with a low proliferation rate), and (ii) poorly differentiated small- or large-cell neuroendocrine carcinomas (NECs) (with a high proliferation rate). For certain NENs (such as pancreatic tumors, higher-grade tumors, and those with DNA damage repair defects), chemotherapy is the main therapeutic approach. Among the different chemotherapic agents, cisplatin and carboplatin, in combination with etoposide, have shown the greatest efficacy in treating NECs compared to NETs. The cytotoxic effects of cisplatin and carboplatin are primarily due to their binding to DNA, which interferes with normal DNA transcription and/or replication. Consistent with this, NECs, which often have mutations in pathways involved in DNA repair (such as Rb, MDM2, BRCA, and PTEN), have a high response to platinum-based chemotherapy. Identifying mutations that affect molecular pathways involved in the initiation and progression of NENs can be crucial in predicting the response to platinum chemotherapy. This review aims to highlight targetable mutations that could serve as predictors of therapeutic response to platinum-based chemotherapy in NENs.

Multidisciplinary Approach for the Management of Metastatic Poorly Differentiated Neuroendocrine Carcinoma of the Pancreas: A Case Report of an Exceptional Responder

ABSTRACT

Poorly differentiated pancreatic neuroendocrine carcinomas (pNECs) are rare, highly aggressive neoplasms. Frequently metastatic at diagnosis, prognosis is poor with median overall survival estimated to be less than 1 year. Although multidisciplinary management, including systemic medications and locoregional therapies aimed at reducing and preventing symptoms caused by mass effect, is the mainstay of treatment for patients with metastatic well-differentiated pancreatic neuroendocrine tumors, rapid progression, organ dysfunction, and poor performance status often preclude initiation of even single-modality palliative chemotherapy for patients with metastatic pNEC, limiting the use of and recommendation for multidisciplinary management.We describe the case of a 51-year-old male patient diagnosed with pNEC metastatic to liver and lymph nodes presenting with impending cholestatic liver failure for whom we were able to successfully initiate and dose-escalate cytotoxic chemotherapy with excellent radiographic response. After multidisciplinary review of his case, the patient underwent pancreaticoduodenectomy and hepatic wedge biopsies, with pathology demonstrating a pathologic complete response to chemotherapy in both the pancreas and liver. Surveillance scans at 2 years from initial diagnosis and 1 year from surgery remain without evidence of locoregional or distant recurrence, highlighting the importance and utility of multidisciplinary management in select cases.

Combination Strategies and Targeted Radionuclide Therapies

Combination models utilising treatments from two or more therapeutic classes are well established in cancer care. In the new era of theranostic (theragnostic) medicine there is an ongoing need to identify and refine novel combination strategies to optimise multidisciplinary care for conditions commonly encountered in nuclear medicine such as neuroendocrine neoplasms (NEN), prostate cancer (PCa), and thyroid cancer, along with seeking advancements in molecular imaging and therapy techniques for other tumour streams. This concise review explores the background of theranostic monotherapy, established approaches to combination strategies in theranostics, and emerging targeted radionuclide therapies in use or under active investigation, with a focus on Australian-led studies.

Chromothripsis is a novel biomarker for prognosis and differentiation diagnosis of pancreatic neuroendocrine neoplasms

This study aimed to identify the role of chromothripsis as a novel biomarker in the prognosis and differentiation diagnosis of pancreatic neuroendocrine neoplasms (pNENs). We conducted next-generation gene sequencing in a cohort of 30 patients with high-grade (G3) pNENs. As a reference, a similar analysis was also performed on 25 patients with low-grade (G1/G2) pancreatic neuroendocrine tumors (pNETs). Chromothripsis and its relationship with clinicopathological features and prognosis were investigated. The results showed that DNA damage response and repair gene alteration and TP53 mutation were found in 29 and 11 patients, respectively. A total of 14 out of 55 patients had chromothripsis involving different chromosomes. Chromothripsis had a close relationship with TP53 alteration and higher grade. In the entire cohort, chromothripsis was associated with a higher risk of distant metastasis; both chromothripsis and metastasis (ENETS Stage IV) suggested a significantly shorter overall survival (OS). Importantly, in the high-grade pNENs group, chromothripsis was the only independent prognostic indicator significantly associated with a shorter OS, other than TP53 alteration or pathological pancreatic neuroendocrine carcinomas (pNECs) diagnosis. Chromothripsis can guide worse prognosis in pNENs, and help differentiate pNECs from high-grade (G3) pNETs.

Complete response induced by nivolumab monotherapy in gastric neuroendocrine carcinoma: a case report

No standard treatment has been established for gastric neuroendocrine carcinoma (G-NEC). We present the case of a patient with recurrent G-NEC who achieved a complete response (CR) with nivolumab. A woman in her 70 s, with no significant medical or family history of illness, underwent an upper gastrointestinal endoscopy, which revealed a Borrmann type 2 tumor in the gastric antrum. Malignant tumor cells were not detected in the endoscopic biopsy samples; however, a malignant gastric tumor was strongly suspected. Therefore, surgical resection was performed, and the tumor was pathologically diagnosed as a G-NEC with liver metastases. Adjuvant etoposide plus carboplatin was administered for four cycles, but recurrence in the liver was observed 5 months after the completion of adjuvant chemotherapy. Ramucirumab plus paclitaxel and irinotecan were introduced as second and third-line treatments. After these treatments, the mesenteric lymph node metastases expanded. Tumor mutation burden (TMB) was low (five mutations/megabase), and microsatellite instability remained stable. However, programmed death-ligand 1 Combined Positive Score (CPS) was ≥ 5 in the resected sample. Therefore, nivolumab monotherapy was introduced as a fourth-line treatment. The mesenteric lymph node metastases exhibited swelling 3 weeks after the initiation of nivolumab; however, they rapidly shrank, and CR was later achieved. Treatment with nivolumab is currently ongoing for 12 months. This is the first report of nivolumab monotherapy in a patient with G-NEC who showed pseudo-progression. Even in TMB-low and microsatellite stable cases, nivolumab may be a viable option for patients with G-NEC.

Comprehensive genomic and transcriptomic characterization of high-grade gastro-entero-pancreatic neoplasms

BACKGROUND

High-grade gastro-entero-pancreatic neoplasms (HG GEP-NENs) can be stratified according to their morphology and Ki-67 values into three prognostic classes: neuroendocrine tumors grade 3 (NETs G3), neuroendocrine carcinomas with Ki-67 < 55% (NECs <55) and NECs with Ki-67 ≥ 55% (NECs ≥55).

METHODS

We analyzed a cohort of 49 HG GEP-NENs by targeted Next-Generation Sequencing (TrueSight Oncology 500), RNA-seq, and immunohistochemistry for p53, Rb1, SSTR-2A, and PD-L1.

RESULTS

Frequent genomic alterations affected TP53 (26%), APC (20%), KRAS and MEN1 (both 11%) genes. NET G3 were enriched in MEN1 (p = 0.02) mutations, while both NECs groups were enriched in TP53 (p = 0.001), APC (p = 0.002) and KRAS (p = 0.02) mutations and tumors with TMB ≥ 10 muts/Mb (p = 0.01). No differentially expressed (DE) gene was found between NECs <55% and NECs ≥55%, while 1129 DE genes were identified between NET G3 and NECs. A slight enrichment of CD4+ and CD8+ T cells in NECs and of cancer-associated fibroblasts and macrophages (M2-like) in NET G3. Multivariate analysis identified histologic type and Rb1 loss as independent prognostic factors for overall survival.

CONCLUSIONS

This study showed that GEP-NET G3 and GEP-NECs exhibit clear genomic and transcriptomic differences, differently from GEP-NECs <55% and GEP-NECs ≥55%, and provided molecular findings with prognostic and potentially predictive value.

[177Lu]Lu-DOTA-TATE plus long-acting octreotide versus high‑dose long-acting octreotide for the treatment of newly diagnosed, advanced grade 2-3, well-differentiated, gastroenteropancreatic neuroendocrine tumours (NETTER-2): an open-label, randomised, phase 3 study

BACKGROUND

There are currently no standard first-line treatment options for patients with higher grade 2-3, well-differentiated, advanced, gastroenteropancreatic neuroendocrine tumours. We aimed to investigate the efficacy and safety of first-line [177Lu]Lu-DOTA-TATE (177Lu-Dotatate) treatment.

METHODS

NETTER-2 was an open-label, randomised, parallel-group, superiority, phase 3 trial. We enrolled patients (aged ≥15 years) with newly diagnosed higher grade 2 (Ki67 ≥10% and ≤20%) and grade 3 (Ki67 >20% and ≤55%), somatostatin receptor-positive (in all target lesions), advanced gastroenteropancreatic neuroendocrine tumours from 45 centres across nine countries in North America, Europe, and Asia. We used interactive response technologies to randomly assign (2:1) patients to receive four cycles (cycle interval was 8 weeks ± 1 week) of intravenous 177Lu-Dotatate plus intramuscular octreotide 30 mg long-acting repeatable (LAR) then octreotide 30 mg LAR every 4 weeks (177Lu-Dotatate group) or high-dose octreotide 60 mg LAR every 4 weeks (control group), stratified by neuroendocrine tumour grade (2 vs 3) and origin (pancreas vs other). Tumour assessments were done at baseline, week 16, and week 24, and then every 12 weeks until disease progression or death. The primary endpoint was progression-free survival by blinded, independent, central radiology assessment. We did the primary analysis at 101 progression-free survival events as the final progression-free survival analysis. NETTER-2 is registered with ClinicalTrials.gov, NCT03972488, and is active and not recruiting.

FINDINGS

Between Jan 22, 2020, and Oct 13, 2022, we screened 261 patients, 35 (13%) of whom were excluded. We randomly assigned 226 (87%) patients (121 [54%] male and 105 [46%] female) to the 177Lu-Dotatate group (n=151 [67%]) and control group (n=75 [33%]). Median progression-free survival was 8·5 months (95% CI 7·7-13·8) in the control group and 22·8 months (19·4-not estimated) in the 177Lu-Dotatate group (stratified hazard ratio 0·276 [0·182-0·418]; p<0·0001). During the treatment period, adverse events (of any grade) occurred in 136 (93%) of 147 treated patients in the 177Lu-Dotatate group and 69 (95%) of 73 treated patients in the control group. There were no study drug-related deaths during the treatment period.

INTERPRETATION

First-line 177Lu-Dotatate plus octreotide LAR significantly extended median progression-free survival (by 14 months) in patients with grade 2 or 3 advanced gastroenteropancreatic neuroendocrine tumours. 177Lu-Dotatate should be considered a new standard of care in first-line therapy in this population.

FUNDING

Advanced Accelerator Applications, a Novartis Company.

NETest in advanced high-grade gastroenteropancreatic neuroendocrine neoplasms

Molecular blood biomarkers are lacking for high-grade (HG) gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN). To histologically distinguish between neuroendocrine carcinoma (NEC), neuroendocrine tumors G3 (NET G3), adenocarcinoma and MINEN is often challenging. The mRNA-based NETest has diagnostic, prognostic and predictive value in neuroendocrine tumors G1-2 but has not been studied in HG GEP-NEN. Patients with advanced HG GEP-NEN were prospectively included in an observational study. A blood sample was collected before the start of chemotherapy and pseudonymised before NETest was performed. NETest results are expressed as an activity index (NETest score) from 0 to 100. The normal score cut-off is 20. Histological sections were pseudonymised before centralized pathological re-evaluation. Samples from 60 patients were evaluable with the NETest. Main primary tumor sites were colon (14), rectum (12), pancreas (11) and esophagus (7). Re-classification: 30 NEC, 12 NET G3, 3 HG-NEN ambiguous morphology, 8 MiNEN, 3 adenocarcinomas with neuroendocrine differentiation (ADNE), 3 adenocarcinomas and 1 NET G2. Elevated NETest (>20) was seen in 38/45 (84%) HG GEP-NEN, all 17 large-cell NEC (100%), 11/13 (85%) small-cell NEC, all ambiguous cases and 7/12 (64%) NET G3. NETest was elevated in 5/8 (63%) MiNEN, 2/3 ADNE, however not in 3 adenocarcinomas. Median survival was 10.2 months (9.6-10.8 95%CI) for evaluable HG GEP-NEN treated with palliative chemotherapy (n = 39), and survival was significantly shorter in patients with NETest >60 with an OS of only 6.5 months. This is the first study to evaluate use of the NETest in advanced HG GEP-NEN. The NETest was almost always elevated in GEP-NEC and in all large-cell NEC. The NETest was also frequently elevated in NET G3 and MiNEN, however cases were limited. Baseline NETest was not predictive for benefit of chemotherapy, however a NETest >60 was prognostic with a shorter survival for patients receiving chemotherapy.

Emerging and under-recognised patterns of colorectal carcinoma morphologies: a comprehensive review

While the overwhelming majority of colorectal carcinomas (CRC) are diagnosed as adenocarcinoma not otherwise specified, there are numerous under-recognised morphologic patterns of CRC. These patterns are recognised by the WHO, appear in reporting manuals for the American Joint Committee of Cancer, and/or are listed on synoptic reports, while many other variants have either fallen out of favour or are emerging as future bona fide patterns. Herein, we discuss 13 variants: serrated adenocarcinoma, micropapillary adenocarcinoma, medullary carcinoma, neuroendocrine carcinoma, mucinous adenocarcinoma, signet-ring cell carcinoma, adenosquamous carcinoma, adenoma-like adenocarcinoma, lymphoglandular complex-like CRC, carcinoma with sarcomatoid components, cribriform-comedo-type adenocarcinoma, undifferentiated carcinoma and low-grade tubuloglandular adenocarcinoma. The purpose of this review is to scrutinise these variants by assessing their clinical characteristics, morphologic cues, as well as pitfalls, and address their prognostic significance. Our analysis aims to bring clarity and updated understanding to these variants, offering valuable insights for pathologists. This contributes to more nuanced CRC diagnosis and treatment strategies, highlighting the importance of recognising a broad spectrum of morphologic patterns in CRC.

Clinical diagnosis and treatment of 37 cases of gallbladder neuroendocrine carcinoma

OBJECTIVE

This study aims to investigate the clinical and pathological characteristics, treatment approaches, and prognosis of gallbladder neuroendocrine carcinoma (GB-NEC).

METHODS

Retrospective analysis was conducted on the clinical data of 37 patients with GB-NEC admitted to Shanxi Cancer Hospital from January 2010 to June 2023. The study included an examination of their general information, treatment regimens, and overall prognosis.

RESULTS

Twelve cases, either due to distant metastasis or other reasons, did not undergo surgical treatment and received palliative chemotherapy (Group 1). Two cases underwent simple cholecystectomy (Group 2); four patients underwent palliative tumor resection surgery (Group 3), and nineteen patients underwent radical resection surgery (Group 4). Among the 37 GB-NEC patients, the average pre-surgery CA19-9 level was 113.29 ± 138.45 U/mL, and the median overall survival time was 19 months (range 7.89-30.11 months). Of these, 28 cases (75.7%) received systemic treatment, 25 cases (67.6%) underwent surgical intervention, and 16 cases (64.0%) received postoperative adjuvant treatment, including combined radiochemotherapy or chemotherapy alone. The median overall survival time was 4 months (0.61-7.40 months) for Group 1 (n = 12), 8 months for Group 2 (n = 2), 21 months (14.67-43.33 months) for Group 3 (n = 4), and 19 months (range 7.89-30.11 months) for Group 4 (n = 19). A significant difference in median overall survival time was observed between Group 1 and Group 4 (P = 0.004).

CONCLUSION

Surgery remains the primary treatment for GB-NEC, with radical resection potentially offering greater benefits to patient survival compared to other therapeutic options. Postoperative adjuvant therapy has the potential to extend patient survival, although the overall prognosis remains challenging.

Gastroenteropancreatic neuroendocrine neoplasms: current development, challenges, and clinical perspectives

Neuroendocrine neoplasms (NENs) are highly heterogeneous and potentially malignant tumors arising from secretory cells of the neuroendocrine system. Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are the most common subtype of NENs. Historically, GEP-NENs have been regarded as infrequent and slow-growing malignancies; however, recent data have demonstrated that the worldwide prevalence and incidence of GEP-NENs have increased exponentially over the last three decades. In addition, an increasing number of studies have proven that GEP-NENs result in a limited life expectancy. These findings suggested that the natural biology of GEP-NENs is more aggressive than commonly assumed. Therefore, there is an urgent need for advanced researches focusing on the diagnosis and management of patients with GEP-NENs. In this review, we have summarized the limitations and recent advancements in our comprehension of the epidemiology, clinical presentations, pathology, molecular biology, diagnosis, and treatment of GEP-NETs to identify factors contributing to delays in diagnosis and timely treatment of these patients.

Molecular Classification of Gastrointestinal and Pancreatic Neuroendocrine Neoplasms: Are We Ready for That?

In the last two decades, the increasing availability of technologies for molecular analyses has allowed an insight in the genomic alterations of neuroendocrine neoplasms (NEN) of the gastrointestinal tract and pancreas. This knowledge has confirmed, supported, and informed the pathological classification of NEN, clarifying the differences between neuroendocrine carcinomas (NEC) and neuroendocrine tumors (NET) and helping to define the G3 NET category. At the same time, the identification genomic alterations, in terms of gene mutation, structural abnormalities, and epigenetic changes differentially involved in the pathogenesis of NEC and NET has identified potential molecular targets for precision therapy. This review critically recapitulates the available molecular features of digestive NEC and NET, highlighting their correlates with pathological aspects and clinical characteristics of these neoplasms and revising their role as predictive biomarkers for targeted therapy. In this context, the feasibility and applicability of a molecular classification of gastrointestinal and pancreatic NEN will be explored.

Emerging Treatment Options for Neuroendocrine Neoplasms of Unknown Primary Origin: Current Evidence and Future Perspectives

Among neuroendocrine neoplasms (NENs), a non-negligible proportion (9-22%) is represented by sufferers of NENs of unknown primary origin (UPO), a poor prognostic group with largely unmet clinical needs. In the absence of standard therapeutic algorithms, current guidelines suggest that the treatment of UPO-NENs should be based on tumor clinical-pathological characteristics, disease burden, and patient conditions. Chemotherapy represents the backbone for the treatment of high-grade poorly differentiated UPO-NENs, usually providing deep but short-lasting responses. Conversely, the spectrum of available systemic therapy options for well-differentiated UPO-NENs may range from somatostatin analogs in indolent low-grade tumors, to peptide receptor radioligand therapy, tyrosine kinase inhibitors (TKIs), or chemotherapy for more aggressive tumors or in case of high disease burden. In recent years, molecular profiling has provided deep insights into the molecular landscape of UPO-NENs, with both diagnostic and therapeutic implications. Although preliminary, interesting activity data have been provided about upfront chemoimmunotherapy, the use of immune checkpoint inhibitors (ICIs), and the combination of ICIs plus TKIs in this setting. Here, we review the literature from the last 30 years to examine the available evidence about the treatment of UPO-NENs, with a particular focus on future perspectives, including the expanding scenario of targeted agents in this setting.

Predictive Nomogram and Propensity Score Matching in Neuroendocrine Carcinoma of the Tubular Gastrointestinal Tract: A US Population-Based Clinical Outcome Study

Background: Neuroendocrine carcinomas (NECs) of the tubular gastrointestinal tract (GI-NECs) are rare and associated with worse clinical outcomes. This population-based study aims to highlight key demographics, clinicopathological factors, and survival outcomes in the US population. Methods: Data from 10,387 patients with GI-NECs were extracted from the Surveillance, Epidemiology, and End Result (SEER) database from 2000 to 2020. Results: Most patients were >40 years old at the time of presentation with a median age of 63 years old, with almost equal ethnic distribution per US population data. The most common primary tumor site was the small intestine (33.6%). The metastatic spread was localized in 34.8%, regional in 27.8%, and distant in 37.3% of cases, and the liver was the most common site of metastasis (19.9%) in known cases of metastases. Most NEC patients underwent surgery, presenting the highest 5-year overall survival of 73.2% with a 95% confidence interval (CI) (95% CI 72.0-74.4%), while chemotherapy alone had the lowest 5-year survival of 8.0% (95% CI 6.4-10.0%). Compared to men, women had a superior 5-year survival rate of 59.0% (95% CI 57.6-60.5%). On multivariate analysis, age > 65 (HR 2.49, 95% CI 2.36-2.54%, p ≤ 0.001), distant metastasis (HR 2.57, 95% CI 2.52-2.62%, p ≤ 0.001), tumor size > 4 mm (HR 1.98, 95%, CI 1.70-2.31%, p ≤ 0.001), esophageal (HR 1.49, 95% CI 0.86-2.58%, p ≤ 0.001), transverse colon (HR 1.95, 95% CI 1.15-3.33%, p ≤ 0.01), descending colon (HR 2.12, 95% CI 1.12, 3.97%, p = 0.02) anorectal sites, and liver or lung metastases were associated with worse survival. Surgical intervention and tumors located in the small intestine or appendix showed a better prognosis. Conclusion: GI-NECs are a group of rare malignancies associated with a poor prognosis. Therefore, epidemiological studies analyzing national databases may be the best alternative to have a more comprehensive understanding of this condition, assess the impact of current practices, and generate prognosis tools.

Systemic Therapy for Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PanNETs) account for approximately 2% of all pancreatic malignancies. Several systemic treatment options have been developed over the last four decades, ranging from cytotoxic chemotherapy and octreotide to newer targeted therapies like sunitinib, cabozantinib, and lenvatinib. Although surgery or liver-directed therapy remains cornerstone for management of metastatic PanNETs, however, they remain unfeasible in majority of cases. PanNETs behave differently than SI-NETs (small intestinal NET); the former is more aggressive and less responsive to somatostatin-based therapies. The optimal sequence of the systemic therapies for the advanced PanNETs depends mainly on the tumor burden, Ki-67 index, and the tempo of the disease. In the end, drawing from ENETS (European Neuroendocrine Tumor Society) and ESMO (European Society for Medical Oncology) guidelines, we propose a working algorithm for the management of advanced PanNETs, not amenable to surgery or liver-directed therapies.

Clinicopathological Findings and Treatment Outcomes of Patients with Primary Hepatobiliary Neuroendocrine Neoplasms: A Retrospective Single-institution Analysis

Objective Primary hepatobiliary neuroendocrine neoplasms (NENs) are rare tumors exhibiting several morphological and behavioral characteristics. Considering the lack of relevant data on this topic, we evaluated the clinicopathological features and treatment outcomes of patients with primary hepatobiliary NENs. Methods/Patients We examined 43 consecutive patients treated at the National Cancer Center Hospital with pathological diagnoses of primary hepatobiliary NEN between 1980 and 2016. Results Nine patients were diagnosed with neuroendocrine tumor (NET) G1, 9 with NET G2, and 25 with neuroendocrine carcinoma (NEC) based on the World Health Organization 2019 classification. Patients with NEC had primary sites across the hepatobiliary organs, although sites in patients with NET G1 and NET G2 only included the liver and ampulla of Vater. Patients with primary extrahepatic bile duct or ampulla of Vater NENs tended to be diagnosed earlier than patients with primary gallbladder NENs. The median survival times in the NET G1, NET G2, and NEC groups were 167.9, 97.4, and 11.1 months, respectively. A good performance status, absence of distant metastases, and low tumor grade were identified as independent predictors of a favorable prognosis. Conclusion The NET-to-NEC ratio and tumor stage distribution at the diagnosis differed depending on the primary site. Patients with G1 and G2 NETs who underwent surgical resection had good prognoses, whereas those with NEC exhibited more advanced disease and poorer prognoses. The performance status, staging classification, and tumor grade are important factors to consider when devising an appropriate treatment strategy and predicting the prognoses of patients with primary hepatobiliary NEN.

Primary Resistance to RET Inhibition in a RET Fusion-Positive Pancreatic Neuroendocrine Carcinoma

We present a 54-year-old White male with a diagnosis of stage IV pancreatic neuroendocrine carcinoma. Next-generation sequencing of the tumor/blood identified a complex tumor genome, which included a rearranged during transfection (RET) gene fusion. The patient initially received cytotoxic chemotherapy with a significant radiographic response. After 4 cycles of chemotherapy, the patient was transitioned to a clinical trial using selpercatinib, a RET inhibitor, as maintenance therapy. Unfortunately, our patient developed progression of disease at the first treatment monitoring scan. Our patient suffered primary resistance to RET-targeted therapy. Proposed mechanisms of resistance include intrinsic resistance of the nuclear receptor co-activator 4-RET fusion to RET inhibition, the RET fusion representing a passenger alteration to another tumorigenic driver pathway and/or decreased efficacy of RET inhibition after platinum-based chemotherapy. Our patient's clinical course highlights the fact that "actionable" genomic alterations do not always equate to patient benefit.

Treatment of poorly differentiated neuroendocrine carcinomas of rectum and anus with chemoradiotherapy: a single-centre evaluation

PURPOSE

Poorly differentiated neuroendocrine carcinoma (PDNEC) of the rectum and anus is a rare disease exhibiting aggressive biological behaviour, even if diagnosed early. Currently, there are no agreed standard treatment approaches and management of locally advanced (LA) and metastatic PDNEC usually follows treatments used in pulmonary neuroendocrine carcinomas because of the similarities with small cell lung cancer. The role of surgery in PDNEC is still debated and the benefit of chemoradiotherapy (CRT) is unknown. This report summarises the experiences of CRT application in anorectal PDNEC in a single Danish institution.

METHODS

All patients with PDNEC treated with concomitant CRT between May 2019 and January 2021 at a University hospital in Denmark were evaluated. Demographics, treatment and survival outcomes were collected and analysed.

RESULTS

Six patients were identified. Five patients received radiotherapy with 50.4 Gy/28 fractions, and four were eligible for curative resection after the CRT. Distant metastasis was observed in four patients at diagnosis. Two patients with synchronous liver metastases were treated with RFA, and one received a liver resection. The treatment was well tolerated with limited side effects. The median follow-up time was 17 months (range 10-36 months), and the median duration of response was 11.2 months (range 8.1 to 24.2 months). One patient achieved a complete response.

CONCLUSION

A multimodal treatment approach with CRT in advanced stages of PDNEC in a highly selected patient group is well tolerated and with a high chance of achieving local control and, combined with surgery, even complete response in a single case.

Patient derived tumoroids of high grade neuroendocrine neoplasms for more personalized therapies

There are no therapeutic predictive biomarkers or representative preclinical models for high-grade gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN), a highly aggressive, fatal, and heterogeneous malignancy. We established patient-derived (PD) tumoroids from biobanked tissue samples of advanced high-grade GEP-NEN patients and applied this model for targeted rapid ex vivo pharmacotyping, next-generation sequencing, and perturbational profiling. We used tissue-matched PD tumoroids to profile individual patients, compared ex vivo drug response to patients' clinical response to chemotherapy, and investigated treatment-induced adaptive stress responses.PD tumoroids recapitulated biological key features of high-grade GEP-NEN and mimicked clinical response to cisplatin and temozolomide ex vivo. When we investigated treatment-induced adaptive stress responses in PD tumoroids in silico, we discovered and functionally validated Lysine demethylase 5 A and interferon-beta, which act synergistically in combination with cisplatin. Since ex vivo drug response in PD tumoroids matched clinical patient responses to standard-of-care chemotherapeutics for GEP-NEN, our rapid and functional precision oncology approach could expand personalized therapeutic options for patients with advanced high-grade GEP-NEN.

Colorectal neuroendocrine carcinoma and mixed neuroendocrine-non-neuroendocrine neoplasm: Prognostic factors and PD-L1 expression

Colorectal neuroendocrine carcinoma (NEC) and mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) are rare malignancies with unclear boundaries and poor prognoses. Our study aimed to conduct a comparative analysis of these diseases, identify prognostic factors, and explore potential therapeutic targets. We collected and analyzed clinicopathological data of NEC and MiNEN in our hospital from 2011 to 2020. Immunohistochemical staining for PD-L1, BRAF V600E, and mismatch repair proteins was performed. We identified 14 NEC and 7 MiNEN cases. Demographic data, including median overall survival (17.1 months for NEC and 18.5 months for MiNEN), did not significantly differ. NEC showed a higher tendency to occur in the rectum and sigmoid colon (p = 0.025) and had fewer cases with metastatic adenocarcinoma components in lymph nodes (p = 0.009) compared to MiNEN. Adverse prognostic factors were age ≥70 years (p = 0.012), N2 nodal status (p = 0.032), and stage IV disease (p = 0.013) based on multivariate Cox regression analysis. We identified five PD-L1 positive cases, two BRAF V600E mutated cases, and one Lynch syndrome case with MSH2 and MSH6 loss. Patients with colorectal NEC or MiNEN exhibited poor survival rates. Adverse prognostic factors included older age, N2 nodal status, and distant metastasis. Potential therapeutic avenues such as immune checkpoint and BRAF inhibitors were suggested for patients with these carcinomas.

Radiosensitizing Favors Response to Peptide Receptor Radionuclide Therapy in Patients With Highly Proliferative Neuroendocrine Malignancies: Preliminary Evidence From a Clinical Pilot Study

AIM/INTRODUCTION

Peptide receptor radionuclide therapy (PRRT) represents a cornerstone of treatment regimens for patients with low proliferative neuroendocrine tumors (NETs). However, in patients experiencing somatostatin receptor-positive NET with higher proliferation rates, a value and potential therapeutic benefit of PRRT as part of multimodal treatment approaches and potentially with addition of radiosensitizing agents has not yet been established.

PATIENTS AND METHODS

In this study, 20 patients with histologically confirmed gastroenteropancreatic (GEP) NET with proliferation rates (Ki67) between 15% and 55% were treated either with PRRT only (n = 10) or with a combination therapy (n = 10) comprising PRRT and capecitabine/temozolomide (CAP/TEM) for at least 2 consecutive cycles.

RESULTS

Disease control rate in patients treated with PRRT alone was 60% (40% stable disease and 20% partial response). Strikingly, in patients treated with PRRT in combination with radiosensitization (CAP/TEM), the disease control rate was 90% (20% stable disease and 70% partial response). The median progression-free survival in the PRRT only group was 12 months, whereas the median progression-free survival in the PRRT + CAP/TEM group was 26 months and has not been yet reached for all patients in the group during the observation period. The median disease-specific survival for patients with PRRT alone was 51 months, whereas this end point was not yet reached in the PRRT + CAP/TEM group. Moreover, the PRRT + CAP/TEM group showed a significantly higher reduction of SSTR-PET-based metabolic tumor volume and chromogranin A levels compared with the PRRT only group. Importantly, adverse events of all grades did not differ between both groups.

CONCLUSIONS

PRRT + CAP/TEM represents a highly promising and well-tolerated therapeutic regimen for patients experiencing somatostatin receptor-positive NET with higher (Ki67 ≥ 15%) proliferation rate. Prospective randomized clinical trials are warranted.

Rare malignant neoplasm of the esophagus: current status and future perspectives

Esophageal cancer is common worldwide, including in Japan, and its major histological subtype is squamous cell carcinoma. However, there are some rare esophageal cancers, including neuroendocrine neoplasm, gastrointestinal stromal tumor, carcinosarcoma and malignant melanoma. The biological and clinical features of these cancers differ from those of esophageal squamous cell carcinoma. Therefore, different treatment strategies are needed for these cancers but are based on limited evidence. Neuroendocrine neoplasm is mainly divided into neuroendocrine tumor and neuroendocrine carcinoma by differentiation and the Ki-67 proliferation index or mitotic index. Epidemiologically, the majority of esophageal neuroendocrine neoplasms are neuroendocrine carcinoma. The treatment of neuroendocrine carcinoma is similar to that of small cell lung cancer, which has similar morphological and biological features. Gastrointestinal stromal tumor is known to be associated with alterations in the c-KIT and platelet-derived growth factor receptor genes and, if resectable, is treated in accordance with the modified Fletcher classification. Carcinosarcoma is generally resistant to both chemotherapy and radiotherapy and requires multimodal treatments such as surgery plus chemotherapy to achieve cure. Primary malignant melanoma is resistant to cytotoxic chemotherapy, but immune checkpoint inhibitors have recently demonstrated efficacy for malignant melanoma of the esophagus. This review focuses on the current status and future perspectives for rare cancer of the esophagus.

Diagnostic and Therapeutic Management of Primary Orbital Neuroendocrine Tumors (NETs): Systematic Literature Review and Clinical Case Presentation

BACKGROUND

The ocular involvement of neuroendocrine neoplasms (NENs) is uncommon and mainly represented by metastases from gastrointestinal and lung neuroendocrine tumors. Primary orbital NENs are even less common and their diagnostic and therapeutic management is a challenge.

METHODS

A systematic review of the literature was conducted from 1966 to September 2023 on PubMed to identify articles on orbital NENs and to summarize their clinical-pathological features, diagnosis and therapeutic management. Furthermore, we presented a case of a locally advanced retro-orbital primary neuroendocrine tumor that was referred to the certified Center of Excellence of Sant'Andrea Hospital, La Sapienza University of Rome, Italy.

RESULTS

The final analysis included 63 records on orbital NENs and 11 records focused on primary orbital NENs. The localization was mostly unilateral and in the right orbit; proptosis or exophthalmos represented the initial symptoms. The diagnostic work-up and therapeutic management was discussed and a diagnostic algorithm for the suspicion of primary orbital NENs was proposed.

CONCLUSIONS

A multidisciplinary approach is required for the management of primary orbital NENs, emphasizing the importance of early referral to dedicated centers for prompt differential diagnosis, tailored treatment, and an improved quality of life and survival.

Novel ensemble feature selection techniques applied to high-grade gastroenteropancreatic neuroendocrine neoplasms for the prediction of survival

BACKGROUND AND OBJECTIVE

Determining the most informative features for predicting the overall survival of patients diagnosed with high-grade gastroenteropancreatic neuroendocrine neoplasms is crucial to improve individual treatment plans for patients, as well as the biological understanding of the disease. The main objective of this study is to evaluate the use of modern ensemble feature selection techniques for this purpose with respect to (a) quantitative performance measures such as predictive performance, (b) clinical interpretability, and (c) the effect of integrating prior expert knowledge.

METHODS

The Repeated Elastic Net Technique for Feature Selection (RENT) and the User-Guided Bayesian Framework for Feature Selection (UBayFS) are recently developed ensemble feature selectors investigated in this work. Both allow the user to identify informative features in datasets with low sample sizes and focus on model interpretability. While RENT is purely data-driven, UBayFS can integrate expert knowledge a priori in the feature selection process. In this work, we compare both feature selectors on a dataset comprising 63 patients and 110 features from multiple sources, including baseline patient characteristics, baseline blood values, tumor histology, imaging, and treatment information.

RESULTS

Our experiments involve data-driven and expert-driven setups, as well as combinations of both. In a five-fold cross-validated experiment without expert knowledge, our results demonstrate that both feature selectors allow accurate predictions: A reduction from 110 to approximately 20 features (around 82%) delivers near-optimal predictive performances with minor variations according to the choice of the feature selector, the predictive model, and the fold. Thereafter, we use findings from clinical literature as a source of expert knowledge. In addition, expert knowledge has a stabilizing effect on the feature set (an increase in stability of approximately 40%), while the impact on predictive performance is limited.

CONCLUSIONS

The features WHO Performance Status, Albumin, Platelets, Ki-67, Tumor Morphology, Total MTV, Total TLG, and SUVmax are the most stable and predictive features in our study. Overall, this study demonstrated the practical value of feature selection in medical applications not only to improve quantitative performance but also to deliver potentially new insights to experts.

Multimodal management of foregut neuroendocrine neoplasms

The foregut, which includes the esophagus, stomach and duodenum, represents one of the most common sites for neuroendocrine neoplasms. These are highly heterogenous with different risk of progression depending on location, cell-type of origin, size, grade and other factors. Various endoscopic and imaging modalities exist to inform therapeutic decision-making, which may be in the form of surgical or endoscopic resection and medical therapy depending on the extent of the disease after diagnostic evaluation. This narrative review aims to explore the literature on the multimodal management of such foregut neuroendocrine neoplasms.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Changes in tumor-to-blood ratio as a prognostic marker for progression-free survival and overall survival in neuroendocrine tumor patients undergoing PRRT

BACKGROUND

Historically, patient selection for peptide receptor radionuclide therapy (PRRT) has been performed by virtue of somatostatin receptor scintigraphy (SRS). In recent years, somatostatin receptor positron emission tomography (SSTR-PET) has gradually replaced SRS because of its improved diagnostic capacity, creating an unmet need for SSTR-PET-based selection criteria for PRRT. Tumor-to-blood ratio (TBR) measurements have shown high correlation with the net influx rate Ki, reflecting the tumor somatostatin receptor expression, to a higher degree than standardized uptake value (SUV) measurements. TBR may therefore predict treatment response to PRRT. In addition, changes in semiquantitative SSTR-PET parameters have been shown to predate morphological changes, making them a suitable metric for response assessment.

METHODS

The institutional database of the Department of Nuclear Medicine (University Hospital Essen) was searched for NET patients undergoing ≥ 2 PRRT cycles with available baseline and follow-up SSTR-PET. Two blinded independent readers reported the occurrence of new lesions quantified tumor uptake of up to nine lesions per patient using SUV and TBR. The association between baseline TBR and changes in uptake/occurrence of new lesions with progression-free survival (PFS) and overall survival (OS) was tested by use of a Cox regression model and log-rank test.

RESULTS

Patients with baseline TBR in the 1st quartile had a shorter PFS (14.4 months) than those in the 3rd (23.7 months; p = 0.03) and 4th (24.1 months; p = 0.02) quartile. Similarly, these patients had significantly shorter OS (32.5 months) than those with baseline TBR in the 2nd (41.8 months; p = 0.03), 3rd (69.2 months; p < 0.01), and 4th (42.7 months; p = 0.03) quartile. Baseline to follow-up increases in TBR were independently associated with shorter PFS when accounting for prognostic markers, e.g., RECIST response (hazard ratio = 2.91 [95%CI = 1.54-5.50]; p = 0.01). This was confirmed with regard to OS (hazard ratio = 1.64 [95%CI = 1.03-2.62]; p = 0.04). Changes in SUVmean were not associated with PFS or OS.

CONCLUSIONS

Baseline TBR as well as changes in TBR were significantly associated with PFS and OS and may improve patient selection and morphological response assessment. Future trials need to assess the role of TBR for therapy monitoring also during PRRT and prospectively explore TBR as a predictive marker for patient selection.

[18F]FDG PET/CT-Avid Discordant Volume as a Biomarker in Patients with Gastroenteropancreatic Neuroendocrine Neoplasms: A Multicenter Study

[18F]FDG PET/CT and [68Ga]Ga-DOTATATE PET/CT are both used to predict tumor biology in neuroendocrine neoplasms. Although the presence of discordant ([18F]FDG-avid/non-[68Ga]Ga-DOTATATE-avid) disease predicts poor prognosis, the significance of the volume of such discordant disease remains undetermined. The aim of this study is to investigate discordant tumor volume as a potential biomarker in patients with advanced gastroenteropancreatic neuroendocrine neoplasms (GEPNENs). Methods: A multicenter retrospective study in patients with advanced GEPNENs and paired [18F]FDG and [68Ga]Ga-DOTATATE PET/CT no more than 85 d apart was conducted. Patients with discordant disease were identified by the NETPET score, and discordant lesions were contoured with a flat [18F]FDG SUV cutoff of 4. The primary variable of interest was the total discordant volume (TDV), which was the sum of the volumes of discordant lesions. Patients were dichotomized into high- and low-TDV cohorts by the median value. The primary endpoint was overall survival. Results: In total, 44 patients were included (50% men; median age, 60 y), with primary cancers in the pancreas (45%), small bowel (23%), colon (20%), and other (12%). Of the patients, 5% had grade 1 disease, 48% had grade 2 disease, and 48% had grade 3 disease (24% well differentiated, 67% poorly differentiated, 10% unknown within the grade 3 cohort). The overall median survival was 14.1 mo. Overall survival was longer in the low-TDV cohort than in the high-TDV cohort (median volume, 43.7 cm3; survival time, 23.8 mo vs. 9.4 mo; hazard ratio, 0.466 [95% CI, 0.229-0.948]; P = 0.0221). Patients with no more than 2 discordant intrahepatic lesions survived longer than those with 2 or more lesions (31.8 mo vs. 10.2 mo, respectively; hazard ratio, 0.389 [95% CI, 0.194-0.779]; P = 0.0049). Conclusion: TDV is a potential prognostic biomarker in GEPNENs and should be investigated in future neuroendocrine neoplasm trials.

[Practical application of immunohistochemistry in pancreatic neuroendocrine neoplasms : Tips and pitfalls]

Pancreatic neuroendocrine neoplasms (PanNEN) are rather rare entities. Morphology, combined with immunohistochemistry, allows typing and grading, thereby leading therapeutic decisions. Depending on tumor stage and differential diagnosis, a broad diagnostic panel may be required. The present work summarizes the minimal diagnostic, prognostic, and predictive markers in PanNEN.Markers of choice for defining a neuroendocrine phenotype are synaptophysin, chromogranin A, and INSM1. The proliferation fraction Ki67 is indispensable for grading, while p53 and Rb1 can help in the differentiation from neuroendocrine carcinoma (NEC). Transcription factors, such as cdx2, TTF‑1, and Islet‑1, can indicate the site of a primary tumor in the setting of a cancer of unknown primary (CUP). DAXX/ATRX immunohistochemistry has mainly prognostic value. Molecular pathology studies currently have little practical value in the diagnosis of PanNEN.An important pitfall in routine diagnostics is the wide spectrum of differential diagnoses mimicking neuroendocrine neoplasms. An expanded immunohistochemical panel is strongly recommended in case of doubt.

Treatment modalities favoring outcome in well-differentiated neuroendocrine tumors G3

Introduction

Neuroendocrine neoplasms (NEN) are a rare and heterogenous group of tumors arising from neuroendocrine cells in multiple organs. Neuroendocrine tumors (NET) G3 encompass a small subgroup accounting for less than 10% of all neuroendocrine neoplasms. In contrast to NET G1 and G2 as well as neuroendocrine carcinomas (NEC), in NET G3 data on treatment and patient outcomes are still limited. Especially in a metastasized tumor stage, the role of surgery, peptide receptor radionucleotide therapy (PRRT), and systemic chemotherapy is not clearly defined.

Methods

In this real-life cohort, we consecutively analyzed clinical outcome in NET G3 patients receiving different diagnostic and treatment.

Results and discussion

We found that even metastasized NET G3 patients undergoing surgery, or receiving radiation, somatostatin analogues (SSA), and PRRT showed a clear survival benefit. Interestingly, all treatment regimen were superior to classical chemotherapeutic agents. In addition, somatostatin receptor (SSTR) PET-CT, FDG PET-CT, and repetitive biopsies were shown to be useful diagnostic and prognostic tools in NET G3. Our study demonstrates that patients with highly proliferative NET G3 might benefit from less aggressive treatment modalities commonly used in low proliferative NEN.

Gastroenteropancreatic neuroendocrine carcinoma in children and adolescents: a population-based study

PURPOSE

Gastroenteropancreatic Neuroendocrine Carcinoma (GEP-NEC) in children is an exceptionally rare and aggressive form of cancer. We aimed to conduct a population-based cohort study to predict overall survival (OS) in pediatric patients with GEP-NEC.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was employed to identify all pediatric patients with GEP-NEC diagnosed between 2000 and 2019. To create survival curves based on various criteria, Kaplane-Meier estimations were utilized. The log-rank test was used to compare survival curves. The variables associated with OS were determined using Cox proportional-hazards regression. Furthermore, we developed a nomogram to predict overall survival in pediatric GEP-NEC patients.

RESULTS

A total of 103 pediatric GEP-NEC patients were identified. The tumors primarily affected females (62.2%). The majority of GEP-NEC was found in the appendix (63.1%), followed by the pancreas (23.3%) and the intestinal tract (13.6%). The highest rates of localized stage (76.9%) and surgery (98.5%) were found in the NEC of appendix origin. However, pancreatic origins had the largest proportion of distant disease (66.7%) but the lowest percentage of surgery (37.5%). Overall 1-year, 3-year, and 5-year survival rates for all patients were 94.4%, 85.4%, and 85.4%, respectively. Tumors of pancreatic origin had the worst survival compared with those of the appendix and intestinal tract. The Cox proportional hazard regression revealed that only site was an important independent predictor of survival.

CONCLUSIONS

Our study revealed that only the primary site was found to be the most important predictor of the OS in pediatric GEP-NEC. It's important to work closely with a multidisciplinary team, including oncologists, surgeons, and other specialists, to determine the most appropriate treatment plan for pediatric GEP-NEC.

Extrapulmonary Neuroendocrine Carcinomas: Current Management and Future Perspectives

Neuroendocrine carcinomas (NECs) are poorly differentiated and highly aggressive epithelial neuroendocrine neoplasms. The most common primary site is the lung, but they may arise in every organ. Approximately 37% of extrapulmonary NECs (EP-NECs) occur in the gastroenteropancreatic (GEP) tract, followed by the genitourinary (GU) system and gynecological tract. As a result of their rarity, there is scant evidence to guide treatment recommendations, and a multidisciplinary approach is essential for the management of such patients. Platinum-based chemotherapy currently represents the standard of care for EP-NECs of any site, mirroring the management of small-cell lung cancer (SCLC), but further approaches are still under investigation. Indeed, ongoing trials evaluating targeted therapies, immune checkpoint inhibitors (ICIs), and radionuclide therapy could provide potentially breakthrough therapeutic options. Given the relative dearth of evidence-based literature on these orphan diseases, the aim of this review is to provide an overview of the pathology and current treatment options, as well as to shed light on the most pressing unmet needs in the field.

The association between jaundice and poorly differentiated pancreatic neuroendocrine neoplasms (Ki67 index > 55.0%)

BACKGROUND

Jaundice occurs in some pancreatic disease. However, its occurrences and role in pancreatic neuroendocrine neoplasms (PNENs) has not been well studied. In this study we showed the association between jaundice and the risk of high grade and poorly differentiated PNENs.

METHODS

Ninety-three patients with head-neck PNENs were included. Poorly differentiated pancreatic neuroendocrine neoplasms were defined by a ki67 index > 55.0%. Logistic regression was used to show the association between demographic information, clinical signs and symptoms and the risk of poorly differentiated tumors. A nomogram model was developed to predict poorly differentiated tumor.

RESULTS

Eight of 93 PNEN patients (8.6%) had jaundice. The age and ki67 index in patients with jaundice were significantly higher than those patients without jaundice. All jaundice occurred in patients with grade 3 PNENs. Mutivariable regression analysis showed that age (odds ratio(OR) = 1.10, 95% confidence interval (CI):1.02-1.19), tumor size (OR = 1.42, 95%CI:1.01-2.00) and jaundice (OR = 14.98, 95%CI: 1.22-184.09) were associated with the risk of poorly differentiated PNENs. The age and size combination showed a good performance in predicting poorly differentiated PNENs (area under the curve (AUC) = 0.81, 95% CI: 0.71-0.90). The addition of jaundice further improved the age- and size-based model (AUC = 0.86, 95% CI: 0.78-0.91). A nomogram was developed based on age, tumor size and jaundice.

CONCLUSION

Our data showed that jaundice was associated with the risk of high grade PNENs and poorly differentiated PNENs.

Predictive Factors of Response to Streptozotocin in Neuroendocrine Pancreatic Neoplasms

Pancreatic neuroendocrine neoplasms (Pan-NENs) may exhibit a heterogeneous clinical course, ranging from indolent to progressive/metastatic behavior. In the latter scenario, streptozocin (STZ) is considered the cornerstone of systemic treatment; however, response to STZ-based chemotherapy may vary among individuals. In this narrative review, we aimed to identify the predictive factors of response to STZ in advanced Pan-NENs. We performed an extensive search in international online databases for published studies and ongoing clinical trials evaluating STZ in Pan-NENs. We found 11 pertinent studies evaluating 17 patient-, tumor-, or treatment-related factors. Age, CgA blood levels, tumor grade, Ki-67% index, anatomical location of the primary tumor, tumor stage, site of metastasis origin, liver tumor burden, extrahepatic spread, functional status, O6-methylguanine-methyltransferase (MGMT) status, line of therapy, and response to previous treatments were all statistically associated with radiological response and/or survival. The identified predictors may help clinicians make appropriate treatment decisions, in this way improving clinical outcomes in patients with advanced Pan-NENs.

Phase II study of everolimus and temozolomide as first-line treatment in metastatic high-grade gastroenteropancreatic neuroendocrine neoplasms

BACKGROUND

The optimal treatment for metastatic high-grade gastroenteropancreatic (GEP) neuroendocrine neoplasms when Ki-67 ≤55% is unknown. A prospective multi-centre phase 2 study was performed to evaluate the efficacy and safety of everolimus and temozolomide as first-line treatment for these patients.

METHODS

Patients received everolimus 10 mg daily continuously and temozolomide 150 mg/m2 for 7 days every 2 weeks. Endpoints included response, survival, safety and quality of life (QoL). Histopathological re-evaluation according to the 2019 WHO classification was performed.

RESULTS

For 37 eligible patients, the primary endpoint with 65% disease control rate (DCR) at 6 months (m) was reached. The response rate was 30%, the median progression-free survival (PFS) 10.2 months and the median overall survival (OS) 26.4 months. Considering 26 NET G3 patients, 6 months DCR was 77% vs. 22% among nine NEC patients (p = 0.006). PFS was superior for NET G3 vs. NEC (12.6 months vs. 3.4 months, Log-rank-test: p = 0.133, Breslow-test: p < 0.001). OS was significantly better for NET G3 (31.4 months vs. 7.8 months, p = 0.003). Grade 3 and 4 toxicities were reported in 43% and 38%. QoL remained stable during treatment.

CONCLUSION

Everolimus and temozolomide may be a treatment option for selected GEP-NET G3 patients including careful monitoring. Toxicity did not compromise QoL.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NTC02248012).

Utility of histopathological revision in the management of gastro-entero-pancreatic neuroendocrine neoplasia

BACKGROUND

Histological evaluation and grading assessment are key points in the diagnostic work-up of gastroentero-pancreatic neuroendocrine neoplasms (GEP-NENs).

AIM

To analyze the impact of histopathological revision on the clinical management of patients with GEP-NEN.

MATERIALS AND METHODS

Patients referred to our Center of Excellence between 2015 and 2021 were included in this study. Immunohistochemical slides at the time of initial diagnosis were reviewed to assess tumor morphology, diagnostic immunohistochemistry, and Ki67.

RESULTS

101 patients were evaluated, with 65 (64.4%) gastrointestinal, 25 (24.7%) pancreatic, and 11 (10.9%) occult neoplastic lesions suspected to be of GEP origin. The main changes resulting from the revision were: first Ki-67 assessment in 15.8% of patients, Ki-67 change in 59.2% of patients and grading modification in 23.5% of patients. An additional immunohistochemical evaluation was performed in 78 (77.2%) patients, leading to a confirmation of GEP origin in 10 of 11 (90.9%) of unknown primary site neoplastic lesions and an exclusion of NEN diagnosis in 2 (2%) patients. After histopathological revision, a significant modification in clinical management was proposed in 42 (41.6%) patients.

CONCLUSIONS

Histopathological revision in a referral NEN center is strongly advised in newly diagnosed GEP-NENs to properly plan prognostic stratification and therapeutic choice.

Study protocol of LANTana: a phase Ib study to investigate epigenetic modification of somatostatin receptor-2 with ASTX727 to improve therapeutic outcome with [177Lu]Lu-DOTA-TATE in patients with metastatic neuroendocrine tumours, UK

INTRODUCTION

Suitability for peptide receptor radionuclide therapy (PRRT) for neuroendocrine neoplasia (NENs) depends on presence of somatostatin receptor-2 (SSTR2) determined by [68Ga]Ga-DOTA-peptide-positron emission tomography (PET). Some patients have low or no uptake on [68Ga]Ga-DOTA-peptide-PET, precluding PRRT. The upstream promoter region of SSRT2 is methylated, with percentage of methylation correlating with SSTR2 expression. Demethylating agents increase uptake on PET imaging in vivo such that tumours previously negative on PET become positive, correlating with a dose dependent increase in tumorous SSTR2 expression. LANTana will determine whether treatment with the demethylating agent, ASTX727, results in re-expression of SSTR2 using [68Ga]Ga-DOTA-peptide-PET to image epigenetic modification of the SSTR2 locus, allowing subsequent PRRT.

METHODS AND ANALYSIS

27 participants with a histological diagnosis of NEN (Ki67<55%) with no or low uptake on baseline [68Ga]Ga-DOTA-TATE-PET/CT will be recruited. Patients will receive 5 days of ASTX727 (fixed dose 35 mg decitabine+100 mg cedazuridine). [68Ga]Ga-DOTA-peptide-PET/CT will be repeated day 8±2; where there is significant uptake greater than liver in most lesions, PRRT will be administered. Primary objective is to determine re-expression of SSTR2 on PET imaging. Tolerability, progression-free survival, overall response and quality of life will be assessed. Methylation in peripheral blood mononuclear cells and tumorous methylation will be evaluated.

ETHICS AND DISSEMINATION

LANTana has ethical approval from Leeds West Research Ethics Committee (REC Reference: 21/YH/0247).Sponsored by Imperial College London and funded by Advanced Accelerator Applications pharmaceuticals. Results will be presented at conferences and submitted to peer-reviewed journals for publication and will be available on ClinicalTrials.gov.

TRIAL REGISTRATION NUMBERS

EUDRACT number: 2020-003800-15, NCT05178693.

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.

Review of Merkel cell carcinoma with solitary pancreatic metastases mimicking primary neuroendocrine tumor of the pancreas

OBJECTIVE/BACKGROUND

Merkel cell carcinoma (MCC) but metastases to the pancreas are very rare. There are only a few cases of isolated metastases of MCC to the pancreas. Because of this rarity, it can be wrongly diagnosed as a neuroendocrine tumor of the pancreas(pNET), especially the poorly differentiated neuroendocrine carcinoma (PNEC) subtype, in which the treatment is vastly different than that of MCC with isolated metastases of the pancreas.

METHODS

An electronic search of the PubMed and google scholar databases was performed to obtain the literature on MCC with pancreatic metastases, using the following search terms: Merkel cell carcinoma, pancreas, and metastases. Results are limited to the following available article types: case reports and case series. We identified 45 cases of MCC with pancreatic metastases from the PubMed and Google Scholar database search and examined their potential relevance. Only 22 cases with isolated pancreatic metastases were taken for review including one case that we encountered.

RESULTS

The results from our review of cases of isolated pancreatic metastases of MCC were compared to the characteristics of the poorly differentiated pancreatic neuroendocrine tumor (PNEC). We found the following: (a) MCC with isolated pancreatic metastases occurred at an older age than PNEC and with male gender predominance (b) Most of the metastases occurred within 2 years of initial diagnosis of MCC (c) Resection of pancreatic mass was the first line treatment in case of resectable PNECs whereas resection of metastases was infrequently performed in MCC with pancreatic metastases.

Surgical treatment of stage IV gastroenteropancreatic neuroendocrine carcinoma: Experience and outcomes in the United States

BACKGROUND AND OBJECTIVES

Surgery for metastatic gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC) has not been well-studied. This retrospective cohort study describes patients in the United States with stage IV GEP-NEC and their survival outcomes segregated by surgery.

METHODS

Patients diagnosed with stage IV GEP-NEC from 2004 to 2017 in the National Cancer Database were categorized into three groups: no surgery, primary site or metastatic site ("single-site") surgery, and primary site and metastatic site ("multisite") surgery. Factors associated with surgical treatment were identified, and risk-adjusted overall survival of each group was compared.

RESULTS

Of 4171 patients included, 958 (23.0%) underwent single-site surgery and 374 (9.0%) underwent multisite surgery. The strongest predictor of surgery was primary tumor type. Compared with no surgery, the risk-adjusted mortality reduction associated with single-site surgery ranged from 63% for small bowel (HR = 0.37, 0.23-0.58, p < 0.001) NEC to 30% for colon and appendix NEC (HR = 0.70, 0.61-0.80, p < 0.001), while the mortality reduction associated with multisite surgery ranged from 77% for pancreas NEC (HR = 0.23, 0.17-0.33, p < 0.001) to 48% for colon and appendix NEC (HR = 0.52, 0.44-0.63, p < 0.001).

CONCLUSIONS

We observed an association between extent of surgical intervention and overall survival for patients with stage IV GEP-NEC. Surgical resection should be further investigated as a treatment option for highly-selected patients with this aggressive disease.

Successful management of a rare case of gallbladder neuroendocrine carcinoma with tumor thrombi

A gallbladder neuroendocrine neoplasm (GB‑NEN) is a bizarre heterogeneous neoplasm arising from neuroendocrine cells, which are present in minimal amounts on the GB mucosa either due to conversion of undifferentiated stem cells, chronic inflammation and resulting in pathological metaplasia or switching of GB adenocarcinoma to neuroendocrine one. Among all the GB malignancies, GB-NEN accounts for approximately 2.1%. A 41-year-old lady presented with right upper abdomen pain and distension for 2 weeks. Contrast CT showed heterogeneously enhancing wall thickening involving fundus-body of the GB with large exophytic component involving segments IV/V of liver, peripheral enhancement and central low attenuating necrotic areas. Middle hepatic and left branch of portal vein was filled with enhancing lesion, tumor thrombi. She underwent left trisectionectomy followed by adjuvant chemotherapy. Postoperative biopsy reported as poorly differentiated unifocal small cell GB-neuroendocrine carcinomas (GB-NEC). Resected margins were free of tumor with periportal lymph nodes negative for tumor. Follow-up PET-CT after six months of treatment completion shows no tumor recurrence or metastases. She has completed 12 months following the surgery and is asymptomatic. As the occurrence of GB-NEC is rare, there are little data regarding etiology, pathogenesis, treatment and prognosis of it. Even though metastasis is early and most frequent to lymph nodes, liver, lung and peritoneum, the presence of tumor thrombus in GB-NEC is rarely reported. Though most reports suggest very poor outcomes, radical surgery followed by adjuvant chemotherapy can yield good short-term results as seen in this case.

Managing Metastatic Extrapulmonary Neuroendocrine Carcinoma After First-Line Treatment

PURPOSE OF REVIEW

Extrapulmonary neuroendocrine carcinoma (EP-NEC) is a rare, aggressive malignancy that can arise from any organ and frequently presents with distant metastases. Advanced disease has a poor prognosis with median overall survival (OS) rarely exceeding 1 year even with systemic therapy. The management paradigm of advanced/metastatic EP-NEC has been extrapolated from small cell lung cancer (SCLC) and commonly consists of 1st line therapy with etoposide and platinum (cisplatin or carboplatin), followed by alternative cytotoxic regimens at the time of progression. Only a minority of patients are able to receive 2nd line therapy, and cytotoxics derived from the SCLC paradigm such as topotecan or lurbinectedin have very limited activity. We aimed to evaluate emerging therapeutic options in the 2nd and later lines and survey potential future developments in this space.

RECENT FINDINGS

After a long period of stagnation in treatment options and outcomes, more promising regimens are gradually being utilized in the 2nd line setting including systemic therapy combinations such as FOLFIRI, FOLFOX, modified FOLFIRINOX, CAPTEM, and, more recently, novel checkpoint inhibitors such as nivolumab and ipilimumab. Simultaneously, advances in the understanding of disease biology are helping to refine patient selection and identify commonalities between NEC and their sites of origin which may eventually lead to additional targeted therapy options. While many questions remain, contemporary developments give grounds for optimism that improved outcomes for EP-NEC will soon be within reach.

Lymph node ratio and hematological parameters predict relapse-free survival in patients with high grade rectal neuroendocrine neoplasms after radical resection: a multicenter prognostic study

BACKGROUND

The prognostic nutritional index (PNI), alkaline phosphatase (ALP), and lymph node ratio (LNR) are reportedly related to prognosis. The aim of this study was to elucidate the clinical importance of the LNR and hematological parameters in patients with high grade rectal neuroendocrine neoplasms (HG-RNENs) who were undergoing radical resection.

METHODS

We reviewed the medical records of patients with HG-RNENs from 17 large-scale medical centers in China (January 1, 2010-April 30, 2022). A nomogram was constructed by using a proportional hazard model. Bootstrap method was used to draw calibration plots to validate the reproducibility of the model. Concordance index (C-Index), decision curve analysis (DCA), and time-dependent area under the receiver operating characteristic curve (TD-AUC) analysis were used to compare the prognostic predictive power of the new model with American Joint Committee on Cancer (AJCC) TNM staging and European Neuroendocrine Tumor Society (ENETS) TNM staging.

RESULTS

A total of 85 patients with HG-RNENs were enrolled in this study. In the 45 patients with HG-RNENs who underwent radical resection, PNI ≤ 49.13 (HR: 3.997, 95% CI: 1.379-11.581, P = 0.011), ALP > 100.0 U/L (HR: 3.051, 95% CI: 1.011-9.205, P = 0.048), and LNR > 0.40 (HR: 6.639, 95% CI: 2.224-19.817, P = 0.0007) were independent predictors of relapse-free survival. The calibration plots suggested that the nomogram constructed based on the three aforementioned factors had good reproducibility. The novel nomogram revealed a C-index superior to AJCC TNM staging (0.782 vs 0.712) and ENETS TNM staging (0.782 vs 0.657). Also, the new model performed better compared to AJCC TNM staging and ENETS TNM staging in DCA and TD-AUC analyses.

CONCLUSIONS

LNR, ALP, and PNI were independent prognostic factors in patients with HG-RNENs after radical resection, and the combined indicator had better predictive efficacy compared with AJCC TNM staging and ENETS TNM staging.

Equivalent Survival between Gastric Large-Cell Neuroendocrine Carcinoma and Gastric Small-Cell Neuroendocrine Carcinoma

BACKGROUND

According to the 2019 World Health Organization (WHO) classification of gastric neuroendocrine neoplasms, gastric neuroendocrine carcinoma (GNEC) can be further divided into gastric large-cell neuroendocrine carcinoma (GLNEC) and gastric small-cell neuroendocrine carcinoma (GSNEC). Whether the prognoses of the two types have a discrepancy has long been disputed.

METHOD

We collected patients diagnosed with GLNEC or GSNEC in the National Cancer Center of China between January 2000 and December 2020. The characteristics and survival outcomes were compared between the two groups. We further verified our conclusion using the SEER dataset.

RESULTS

A total of 114 GNEC patients, including 82 patients with GLNEC and 32 patients with GSNEC, have completed treatment in our hospital. Clinicopathologic differences were not observed between patients with GSNEC and GLNEC concerning the sex, age, body mass index, Charlson Comorbidity Index, tumor location, tumor size, stage, treatment received, the expression of neuroendocrine markers (CD56, Chromogranin A, synaptophysin), and score on the Ki-67 index. The 1-year, 3-year, and 5-year overall survival rates of GLNEC and GSNEC were 89.0%, 60.5%, and 52.4%, and 93.8%, 56.3%, and 52.7%, which showed no statistically significant differences. This result was confirmed further by using the SEER dataset after the inverse probability of treatment weighting.

CONCLUSIONS

Although with different cell morphology, the comparison of prognosis between the GLNEC and GSNEC has no significant statistical difference.