Management and Prognosis of Localized Duodenal Neuroendocrine Neoplasms

Optimal surgical approach for digestive neuroendocrine neoplasia primaries: Oncological benefits versus short and long-term complications

The rising incidence and the accumulating prevalence of neuroendocrine neoplasia (NEN) in the population makes this a common, prevalent and a clinically relevant disease group. Surgical resection represents the only potentially curative treatment for digestive NENs. Thus, resection should in principle be considered for all patients with NEN, although taking the patients age, relevant comorbidity, and performance status into account for operability. Patients with insulinomas, NEN of the appendix and rectal NENs are usually cured by surgery alone. However, less than a third of patients are amendable to curative surgery alone at time of diagnosis. Furthermore, recurrence is common and may occur years after primary surgery, hence the long follow-up time recommended in most NENs (>10 years). As many patients with NENs present with locoregional or metastatic disease, there is considerable debate regarding the role of debulking surgery in these settings. However, good long-term survival can be achieved in a considerable proportion of patients, with 50-70% alive up to 10 years after surgery. Location and grade are the main determinants of long-term survival. Here we present considerations to surgery for primary neuroendocrine tumors in the digestive tract.

Gastroenteropancreatic Neuroendocrine Tumors-Current Status and Advances in Diagnostic Imaging

Gastroenteropancreatic neuroendocrine neoplasia (GEP-NEN) is a heterogeneous and complex group of tumors that are often difficult to classify due to their heterogeneity and varying locations. As standard radiological methods, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET/CT) are available for both localization and staging of NEN. Nuclear medical imaging methods with somatostatin analogs are of great importance since radioactively labeled receptor ligands make tumors visible with high sensitivity. CT and MRI have high detection rates for GEP-NEN and have been further improved by developments such as diffusion-weighted imaging. However, nuclear medical imaging methods are superior in detection, especially in gastrointestinal NEN. It is important for radiologists to be familiar with NEN, as it can occur ubiquitously in the abdomen and should be identified as such. Since GEP-NEN is predominantly hypervascularized, a biphasic examination technique is mandatory for contrast-enhanced cross-sectional imaging. PET/CT with somatostatin analogs should be used as the subsequent method.

Comparable long-term survival outcomes of endoscopic therapy versus surgical therapy for T1-2N0M0 duodenal neuroendocrine tumors

BACKGROUND AND STUDY AIMS

The optimal treatment modality for T1-2N0M0 duodenal neuroendocrine tumors (DNETs) is still controversial. In this study, long-term survival outcomes were compared between the endoscopic therapy and surgical therapy for T1-2N0M0 DNETs using the Surveillance, Epidemiology, and End Results (SEER) database.

PATIENTS AND METHODS

Patients with DNETs from the SEER database were selected from 2004 to 2015. We used the Kaplan-Meier method and log-rank test to compare long-term survival results between the endoscopic therapy and surgical therapy. An analysis of the multivariable Cox proportional hazards model was performed to identify risk factors for patient prognoses. The 1:1 propensity score matching (PSM) was performed to balance baseline data.

RESULTS

A total of 816 patients with DNETs were included, of which 578 patients (70.8%) received endoscopic therapy and 238 patients (29.2%) received surgical therapy. Before the PSM, there was no difference between the two groups of patients with DNETs on long-term survival [5-year OS (86.1% vs. 87.9%, P = 0.45), 10-year OS (72.5% vs. 72.3%, P = 0.45)]. After adjusting covariates, we found endoscopic therapy and surgical therapy groups had comparable risks of overall survival (HR 0.86, 95% CI 0.60-1.23, P = 0.409) and cancer-specific survival (HR 1.68, 95% CI 0.74-3.83, P = 0.214). In the post-PSM analysis, there was no discernible difference between the endoscopic therapy and surgical therapy group.

CONCLUSIONS

Our study found that for T1-2N0M0 DNETs patients, whose long-term OS and CSS results were similar for the endoscopic and surgical therapy groups. For these patients, endoscopic resection might be an optimal therapy modality.

Development and Validation of Prognostic Nomograms for Periampullary Neuroendocrine Neoplasms: A SEER Database Analysis

(1) Background: Periampullary neuroendocrine neoplasms (NENs) are rare tumors that lack a prognostic prediction model. We aimed to design comprehensive and effective nomograms to predict prognosis; (2) Methods: Univariate and multivariate Cox analyses were used to screen out significant variables for the construction of the nomograms. The discrimination and calibration of the nomograms were carried out using calibration plots, concordance indices (C-indices), and area under time-dependent receiver operating characteristic curves (time-dependent AUCs). Decision curve analysis (DCA) was used to compare the clinical applicability of the nomograms, TNM (Tumor- Node-Metastasis) stage, and SEER stage; (3) Results: The independent risk factors for overall survival (OS) and cancer-specific survival (CSS) of patients with periampullary NENs included age, tumor size, histology, differentiation, N stage, M stage, and surgery, which were used to construct the nomograms. The calibration curves and C-indices showed a high degree of agreement between the predicted and actual observed survival rates. The AUCs displayed good calibration and acceptable discrimination of the nomograms. Additionally, the DCA curves indicated that the nomograms showed better clinical applicability; (4) Conclusions: We developed and validated nomogram prognostic models for patients with periampullary NENs. The nomograms provided insightful and applicable tools to evaluate prognosis.

Survival comparison between endoscopic and surgical resection for non-ampullary duodenal neuroendocrine tumor (1-2 cm)

The treatment plan for non-ampullary duodenal neuroendocrine tumors (d-NETs) with diameters 1-2 cm remains controversial. We therefore aimed to compare the prognostic effects of endoscopic treatment and surgical resection on non-ampullary d-NETs with 1-2 cm diameters. A total of 373 eligible patients were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was performed to match patients 1:1 according to clinicopathological characteristics. Disease-specific survival (DSS) and overall survival (OS) were calculated. Before PSM, there was no significant difference in DSS or OS (all P > 0.05), but the T stage, N stage, and TNM stage were significantly different between the two surgical methods (all P < 0.05). After 1:1 PSM, the differences in clinicopathological characteristics were significantly reduced (all P > 0.05). Survival analysis showed that tumor grade was correlated with DSS and that age was correlated with OS (all P < 0.05); however, the surgical method and other clinicopathological characteristics were not correlated with prognosis (all P > 0.05). Subgroup survival analysis of patients with T2N0M0 disease and tumors invading the lamina propria or submucosa showed that the 5-year DSS and OS rates were not significantly different according to the surgical approach (all P > 0.05). The surgical approach has no significant effect on the prognosis of patients with non-ampullary d-NETs with 1-2 cm diameters, especially those with T2N0M0 disease. This suggests that endoscopic treatment may be a preferred option for these patients.

Ampullary Neuroendocrine Neoplasms: Identification of Prognostic Factors in a Multicentric Series of 119 Cases

Neuroendocrine neoplasms (NENs) of the major and minor ampulla are rare diseases with clinico-pathologic features distinct from non-ampullary-duodenal NENs. However, they have been often combined and the knowledge on prognostic factors specific to ampullary NENs (Amp-NENs) is limited. The aim of this study was to identify factors associated with metastatic potential and patient prognosis in Amp-NENs. We clinically and histologically investigated an international series of 119 Amp-NENs, comprising 93 ampullary neuroendocrine tumors (Amp-NETs) and 26 neuroendocrine carcinomas (Amp-NECs). Somatostatin-producing tubulo-acinar NET represented the predominant Amp-NET histologic subtype (58 cases, 62%, 12 associated with type 1 neurofibromatosis). Compared to Amp-NETs, Amp-NECs arose in significantly older patients and showed a larger tumor size, a more frequent small vessel invasion, a deeper level of invasion and a higher rate of distant metastasis, and, importantly, a tremendously worse disease-specific patient survival. In Amp-NETs, the WHO grade proved to be a strong predictor of disease-specific survival (hazard ratio: 12.61, p < 0.001 for G2 vs G1), as well as patient age at diagnosis > 60 years, small vessel invasion, pancreatic invasion, and distant metastasis at diagnosis. Although nodal metastatic disease was not associated with survival by itself, patients with > 3 metastatic lymph nodes showed a worse outcome in comparison with the remaining Amp-NET cases with lymphadenectomy. Tumor epicenter in the major ampulla, small vessel invasion, and tumor size > 16 mm were independent predictors of nodal metastases in Amp-NETs. In conclusion, we identified prognostic factors, which may eventually help guide treatment decisions in Amp-NENs.

Management of Duodenal Neuroendocrine Tumors: Surgical versus Endoscopic Mucosal Resection

BACKGROUND

Management of duodenal neuroendocrine tumors (DNETs) is not standardized, with smaller lesions (< 1-2 cm) generally treated by endoscopic mucosal resection (EMR) and larger DNETs by surgical resection (SR). This study reviewed how patients were selected for treatment and compared outcomes.

PATIENTS AND METHODS

Patients with DNETs undergoing resection were identified through institutional databases, and clinicopathologic data recorded. χ² and Wilcoxon tests compared variables. Survival was determined by Kaplan-Meier, and Cox regression tested association with survival.

RESULTS

Among 104 patients, 64 underwent EMR and 40 had SR. Patients selected for SR had larger tumor size, younger age, and higher T, N, and M stage. There was no difference in progression-free (PFS) or overall survival (OS) between SR and EMR. In 1-2 cm DNETs, there was no difference in PFS between SR and EMR [median not reached (NR), P = 0.1]; however, longer OS was seen in SR (median NR versus 112 months, P = 0.03). In 1-2 cm DNETs, SR patients were more likely to be node-positive and younger. After adjustment for age, resection method did not correlate with survival. Comparison of surgically resected DNETs versus jejunoileal NETs revealed longer PFS (median NR versus 73 months, P < 0.001) and OS (median NR versus 119 months, P = 0.004) DISCUSSION: In 1-2 cm DNETs, there was no difference in survival between EMR and SR after adjustment for age. Recurrences could be salvaged, suggesting that EMR is a reasonable strategy. Compared with jejunoileal NETs, DNETs treated by SR had improved PFS and OS.

ASO Author Reflections: Endoscopic Management is Reasonable for <2 cm Duodenal Neuroendocrine Tumors

Optimal management of duodenal neuroendocrine tumors (DNETs) has not been well-defined, especially for DNETs 1-2 cm in size. Recent studies comparing endoscopic mucosal resection (EMR) and surgical resection demonstrate EMR is safe and effective for these intermediate-sized DNETs. Expert and consensus guidelines could consider updating recommendations to reflect the outcomes of EMR in DNETs and the importance of endoscopic surveillance in these patients to evaluate for local recurrence.

Gastro-entero-pancreatic neuroendocrine neoplasia: The rules for non-operative management

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) with favorable pathological and clinical features may be considered as indolent lesions, and therefore be amenable to conservative management. According to the primary tumor site, different non-aggressive approaches, based on endoscopic resection or simple active surveillance, can be proposed to selected patients fulfilling specific criteria. Tumor size, Ki67 proliferative index and depth of invasion are markers that can be used in order to identify these subjects. Patients with type I gastric NENs <1 cm as well as those with non-ampullary duodenal NENs <1 cm with no associated syndrome can be safely managed by endoscopic resection. On the other hand, an active surveillance approach is preferred over surgery for patients with asymptomatic, non-functioning pancreatic NENs ≤2 cm without dilation of the main pancreatic duct or bile duct. As far as NENs of the appendix are concerned, appendectomy should be considered as curative when a R0 resection has been achieved in the presence of a tumor ≤1.5 cm, graded as G1 and without lymphovascular invasion. Finally, G1 rectal NENs ≤1 cm without invasion of the muscular layer can be safely treated by endoscopic resection. Therefore, surgeons should be aware of the existence of indolent GEP-NENs, in order to avoid unnecessary operations with associated postoperative complications.