Localized high-grade gastroenteropancreatic neuroendocrine tumors: Defining prognostic and therapeutic factors for a disease of increasing clinical significance

Resection of the primary tumor improves the prognosis of gastrointestinal neuroendocrine neoplasms with liver metastases: mutual validation based on SEER database and institutional data

BACKGROUND

Gastrointestinal Neuroendocrine Neoplasms (GI-NENs) often result in liver metastases, and the role of Primary Tumor Resection (PTR) in managing GI-NENs with liver metastases (GI-NENLM) is still debated. This study aimed to investigate the potential benefits of PTR in treating GI-NENLM by analyzing data from the Surveillance, Epidemiology, and End Results Program (SEER) and the First Affiliated Hospital of Sun Yat-sen University (FAH).

METHODS

The SEER Registry 17 database and the FAH clinical pathology database were used to collect clinicopathology data for GI-NENLM diagnosed between 2010 and 2019 and between 2011 and 2022, respectively. Propensity score matching (PSM) was used to match the clinicopathological characteristics of patients from both cohorts. Inverse probability weighting (IPTW) was used to weigh the PTR and non-PTR groups. The primary endpoint was overall survival (OS).

RESULTS

After matching, 155 patients from the SEER database were matched to the FAH cohort. PTR was significantly associated with better prognosis in PSM-matched/unmatched SEER cohorts (P < 0.01) and in the FAH cohort even after eliminating selection bias using IPTW (p < 0.01). Subgroup analysis suggests that the cohort consisting of patients aged 55 years or older, individuals with colorectal primary tumors, those at the T1 disease stage, and those without extrahepatic metastasis may potentially benefit from PTR. Interaction analysis showed no significant interaction between PTR and other clinical and pathological factors except for age.

CONCLUSION

The employment of PTR in patients with GI-NENLM is significantly correlated with individual survival benefits. We support performing PTR on carefully evaluated patients.

Small bowel neuroendocrine tumors: An analysis of clinical presentation, diagnostic workup and surgical approach—A single center retrospective study

Background

Neurocrine neoplasms (NEN) of the small bowel (SBNEN) are a rare entity and mostly asymptomatic. The aim of this study was to explore trends in the clinical presentation, diagnostic workup, surgical approach and oncological outcome in patients with SBNEN at our surgical department.

Materials and methods

All patients who underwent surgical resection for SBNEN from 2004 to 2020 at our department were enrolled in this single center retrospective study.

Results

A total of 32 patients were included in this study. In most cases, the diagnosis was based on incidental findings during endoscopy or radiographic imaging (n = 23; 72%). Twenty cases had a G1 tumor and 12 cases a G2 tumor. The 1-, 3- and 5-year overall survival (OS) were 96%, 86% and 81%, respectively. Patients with a tumor more than 30 mm had a significantly lower OS (p = 0.01). For G1 tumors, the estimated disease-free survival (DFS) was 109 months. Again, the DFS was significantly lower when the tumor had more than 30 mm in diameter (p = 0.013).

Conclusion

Due to the mostly asymptomatic presentation, the diagnostic workup can be difficult. An aggressive approach and a strict follow-up seem to be important for the oncological outcome.

Expression of p53 and Rb reveal subtypes of gastric neuroendocrine carcinoma with distinct prognosis

Gastric neuroendocrine carcinoma (NEC) is a rare tumor with a poor prognosis. Due to its rarity and disparity in prevalence across populations, there is limited data on gastric NEC. TP53 and RB1 genetic alterations or expression were reported for predictive value in neuroendocrine neoplasm and classification in pulmonary large cell NEC. This study investigated the genetic alteration and protein expression of TP53 and RB1 in gastric NEC. Thirty-nine patients were categorized as type A and B subtypes by p53 and Rb expression. Patients with concurrent abnormal p53 and Rb expression were defined as the type A group, and the remainder were defined as the type B group. Significant differences in TNM stages, tumor size, and lymph node metastasis were observed between the two subtypes. Type A characteristic is an independent predictor for worse overall survival (HR: 3.27; 95% CI: 1.12-9.58; p = .022). We further evaluated and compared immunotherapy-related markers, including PD-L1 expression, CD8 T cell infiltration, tumor mutation burden, and microsatellite instability in these two subtypes, whereas no significant differences were detected.

Treatment Approaches and Outcome of Patients with Neuroendocrine Neoplasia Grade 3 in German Real-World Clinical Practice

Simple Summary

Grade 3 neuroendocrine neoplasms (NEN G3) are a rare and heterogeneous subtype of NEN and include poorly differentiated neuroendocrine carcinomas and well-differentiated neuroendocrine tumors G3 (NET G3). Standard chemotherapy with platinum plus etoposide may not be appropriate for all subgroups, but more tailored approaches suffer from the lack of data. In our study, we provide real-world data from a large center-based cohort of the German NET Registry and hope to stimulate efforts to conduct clinical trials for well-defined entities.

Abstract

Background: Neuroendocrine neoplasia grade 3 (NEN G3) represents a rare and heterogeneous cancer type with a poor prognosis. The aim of our study was to analyze real-world data from the German NET Registry with a focus on therapeutic and prognostic aspects. Methods: NEN G3 patients were identified within the German NET Registry. Demographic data and data on treatments and outcomes were retrieved. Univariate analyses were performed using the Kaplan–Meier-method. Multivariate analysis was performed using a Cox proportional hazard model. Results: Of 445 included patients, 318 (71.5%) were diagnosed at stage IV. Well-differentiated morphology (NET G3) was described in 31.7%, 60% of cases were classified as neuroendocrine carcinoma (NEC), and the median Ki67 value was 50%. First-line treatment comprised chemotherapy in 43.8%, with differences in the choice of regimen with regard to NET or NEC, and surgery in 41.6% of patients. Median overall survival for the entire cohort was 31 months. Stage, performance status and Ki67 were significant prognostic factors in multivariate analysis. Conclusions: The survival data of our national registry compare favorably to population-based data, probably mainly because of a relatively low median Ki67 of 50%. Nevertheless, the best first- and second-line approaches for specific subgroups remain unclear, and an international effort to fill these gaps is needed.

Role of surgical treatments in high-grade or advanced gastroenteropancreatic neuroendocrine neoplasms

Over the last 40 years, the incidence and prevalence of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have continued to increase. Compared to other epithelial neoplasms in the same organ, GEP-NENs exhibit indolent biological behavior, resulting in more chances to undergo surgery. However, the role of surgery in high-grade or advanced GEP-NENs is still controversial. Surgery is associated with survival improvement of well-differentiated high-grade GEP-NENs, whereas poorly differentiated GEP-NENs that may benefit from resection require careful selection based on Ki67 and other tissue biomarkers. Additionally, surgery also plays an important role in locally advanced and metastatic disease. For locally advanced GEP-NENs, isolated major vascular involvement is no longer an absolute contraindication. In the setting of metastatic GEP-NENs, radical intended surgery is recommended for patients with low-grade and resectable metastases. For unresectable metastatic disease, a variety of surgical approaches, including cytoreduction of liver metastasis, liver transplantation, and surgery after neoadjuvant treatment, show survival benefits. Primary tumor resection in GEP-NENs with unresectable metastatic disease is associated with symptom control, prolonged survival, and improved sensitivity toward systemic therapies. Although there is no established neoadjuvant or adjuvant strategy, increasing attention has been given to this emerging research area. Some studies have reported that neoadjuvant therapy effectively reduces tumor burden, improves the effectiveness of subsequent surgery, and decreases surgical complications.

Management of Large Cell Neuroendocrine Carcinoma

BACKGROUND

Large cell neuroendocrine carcinoma (LCNEC) is a rare, aggressive cancer with a dismal prognosis. The majority of cases occur in the lung and the gastrointestinal tract; however, it can occur throughout the body. Recently advances in the understanding of the molecular underpinnings of this disease have paved the way for additional novel promising therapies. This review will discuss the current best evidence for management of LCNEC and new directions in the classification and treatment of this rare disease.

METHODS

We performed a PubMed search for "Large cell neuroendocrine carcinoma" and "High grade neuroendocrine carcinoma." All titles were screened for relevance to the management of LCNEC. Papers were included based on relevance to the management of LCNEC.

RESULTS

Papers were included reviewing both pulmonary and extra pulmonary LCNEC. We summarized the data driven best practices for the management of both early and advanced stage LCNEC. We describe emerging therapies with promising potential.

DISCUSSION

LCNEC are rare and aggressive neoplasms. In advanced disease, the historical regimen of platinum based therapy in combination with etoposide or irinotecan remains among the commonly used first line therapies, however for extra thoracic LCNEC regimens like FOLFOX, FOLFOIRI and CAPTEM can also be used. Further effective and safe treatment options are desperately needed. Recently, new advances including a new understanding of the genetic subcategories of LCNEC and immunotherapy agents may guide further treatments.

Outcomes of non-metastatic poorly differentiated gastroenteropancreatic neuroendocrine neoplasms treated with surgery: a real-world population-based study

OBJECTIVE

To assess the outcomes of non-metastatic poorly differentiated gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) treated with radical surgery.

METHODS

Surveillance, Epidemiology, and End Results (SEER) database (1998-2015) was accessed, and patients with non-metastatic poorly differentiated/undifferentiated GEP-NENs were reviewed. Multivariable Cox regression analysis was used to evaluate factors affecting overall survival (OS) and cancer-specific survival (CSS). Patients treated with radical surgery were matched to those who did not undergo surgery through propensity score matching and Kaplan-Meier survival estimates were used to evaluate the impact of surgery in the post-propensity cohort.

RESULTS

A total of 1517 patients were included. Within multivariable Cox regression models and compared to no surgery, radical surgery was associated with improved OS (HR: 0.41; 95% CI: 0.34-0.50) and CSS (HR: 0.37; 95% CI: 0.29-0.47). A total of 233 patients who underwent no surgery were then matched to 233 patients who underwent radical surgery. Within the post-propensity cohort, radical surgery was associated with improved OS (P < 0.001).

CONCLUSIONS

Radical surgery is associated with improved survival outcomes in patients with non-metastatic poorly differentiated GEP-NENs. Further studies are required to better identify the best timing of radical surgery within the context of multimodal management.

Tumour grade and primary site predict patterns of recurrence and survival in patients with resected gastroenteropancreatic neuroendocrine tumors

BACKGROUND

Patterns of recurrence help to inform surveillance of patients with resected gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

METHODS

Patients with GEP-NETs in British Columbia, Canada (2004-2015) were reviewed. Associations between tumor characteristics, recurrence and survival were analyzed.

RESULTS

Among 759 patients, 41%, 25%, and 17% had grade 1, 2, and 3 disease, respectively. 387 patients had R0/R1 resections, of which 30% recurred (median 25 months). 5-year incidence of recurrence was 22% (grade 1), 46% (grade 2), and 59% (grade 3) (p < 0.001). Grade predicted distant recurrence (Grade 2 HR 1.89, 95% CI 1.16-3.07; p = 0.011; Grade 3 HR 3.29, 95% CI 1.81-5.99; p < 0.001). Compared to small bowel NETs, pancreas NETs had less peritoneal recurrence (OR 0.15, 95% CI 0.03-0.68, p = 0.014). No patients had isolated pulmonary recurrences.

CONCLUSION

Higher grade tumors and pancreatic NETs require more frequent surveillance. Evidence is limited for pulmonary surveillance.

Comparison and clinical implementation of quality of life tools in patients with small bowel neuroendocrine tumors treated with Lu-DOTA-TATE PRRT

Aim: This study assesses if clinically developed quality of life (QoL) tools are as effective in small bowel neuroendocrine tumors (NETs) as NET-specific research questionnaires. Methods: QoL in patients with small bowel NETs treated with Lu-DOTA-TATE was assessed with The European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, QLQ-GI.NET21 and Edmonton Symptom Assessment System Revised (ESAS-r) at baseline and after four treatments. Repeated measures ANOVA was performed. Results: Both EORTC and ESAS-r demonstrated maintained overall QoL. EORTC demonstrated statistically and clinically significant improvement in insomnia, diarrhea, gastrointestinal, endocrine symptoms and social function. ESAS-r demonstrated statistically and clinically significant improvement in overall total symptom distress score. Conclusion: ESAS-r is quick and easy to interpret. It is not as sensitive to individual symptoms but does track overall function. EORTC assessment is more complex, but better reflects QoL for NET specific symptoms.

Leveraging machine learning techniques for predicting pancreatic neuroendocrine tumor grades using biochemical and tumor markers

BACKGROUND

The incidence of pancreatic neuroendocrine tumors (PNETs) is now increasing rapidly. The tumor grade of PNETs significantly affects the treatment strategy and prognosis. However, there is still no effective way to non-invasively classify PNET grades. Machine learning (ML) algorithms have shown potential in improving the prediction accuracy using comprehensive data.

AIM

To provide a ML approach to predict PNET tumor grade using clinical data.

METHODS

The clinical data of histologically confirmed PNET cases between 2012 and 2018 were collected. A method of minimum P for the Chi-square test was used to divide the continuous variables into binary variables. The continuous variables were transformed into binary variables according to the cutoff value, while the P value was minimum. Four classical supervised ML models, including logistic regression, support vector machine (SVM), linear discriminant analysis (LDA) and multi-layer perceptron (MLP) were trained by clinical data, and the models were labeled with the pathological tumor grade of each PNET patient. The performance of each model, including the weight of the different parameters, were evaluated.

RESULTS

In total, 91 PNET cases were included in this study, in which 32 were G1, 48 were G2 and 11 were G3. The results showed that there were significant differences among the clinical parameters of patients with different grades. Patients with higher grades tended to have higher values of total bilirubin, alpha fetoprotein, carcinoembryonic antigen, carbohydrate antigen 19-9 and carbohydrate antigen 72-4. Among the models we used, LDA performed best in predicting the PNET tumor grade. Meanwhile, MLP had the highest recall rate for G3 cases. All of the models stabilized when the sample size was over 70 percent of the total, except for SVM. Different parameters varied in affecting the outcomes of the models. Overall, alanine transaminase, total bilirubin, carcinoembryonic antigen, carbohydrate antigen 19-9 and carbohydrate antigen 72-4 affected the outcome greater than other parameters.

CONCLUSION

ML could be a simple and effective method in non-invasively predicting PNET grades by using the routine data obtained from the results of biochemical and tumor markers.

High-Grade Gastrointestinal Neuroendocrine Carcinoma Management and Outcomes: A National Cancer Database Study

BACKGROUND

High-grade neuroendocrine carcinomas are rare in the gastrointestinal tract. However, treatment patterns and outcomes have not been well described.

SUBJECTS, MATERIALS, AND METHODS

The National Cancer Database was analyzed. The primary objective was to describe the clinical outcomes and identify prognostic factors. Univariate and multivariate analyses were done to identify factors associated with patient outcome.

RESULTS

A total of 1,861 patients were identified between 2004 and 2013. The mean age was 63 years (standard deviation ±13). The majority of the patients (78.1%) were non-Hispanic whites. The most common primary sites were pancreas (pancreatic neuroendocrine tumor [PNET] = 19.4%), large intestine (18.1%), esophagus (17.8%), and rectum (15.5%). Stage at presentation was I (6.6%), II (10.5%), III (18%) and IV (64.6%). Only 1.6% of the patients had brain metastases. Surgical resection was the primary therapy in 27.9%, and their median overall survival (OS) was 13.3 months. Patients treated with palliative chemotherapy had a median OS of 11.2 months, compared with 1.7 months for untreated patients. The median OS for high-grade PNET was 6 months, compared with 9.9 months for other high-grade gastrointestinal neuroendocrine carcinomas (HG GI NEC). On univariable analysis, age < 65 years (hazard ratio [HR] 0.72; 0.66-0.8; p < .001) and treatment at an academic center (HR 0.88; 0.79-0.99; p < .034) were associated with improved survival. Multivariable analysis confirmed prognostic advantage of treatment at an academic center.

CONCLUSION

This is the largest series of HG GI NEC. Most patients present with metastatic disease, and overall survival remains poor. Treatment at an academic center, younger age, and use of chemotherapy were associated with improved survival. Multiagent chemotherapy was found to be associated with superior survival compared with single-agent chemotherapy, which was superior to no chemotherapy. Temporal sequences of chemotherapy, surgery, and radiation administration were not found to be associated with survival differences on multivariable analysis.

IMPLICATIONS FOR PRACTICE

Management of patients with high-grade gastrointestinal neuroendocrine carcinomas (HG GI NEC) is based on experience with small-cell lung cancer. In this retrospective review, most patients had advanced disease and pancreatic primary had worse outcomes. Treatment at an academic center, younger age, and use of chemotherapy are associated with improved survival. Patients with early-stage disease treated with resection alone had inferior outcomes compared with patients who received neoadjuvant or adjuvant therapy, suggesting that micrometastases contribute to poor surgical outcomes. The relatively high proportion of positive surgical margin favors downstaging with neoadjuvant therapy to improve resection and lower the risk of systemic recurrence.

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

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

Incidence trend and conditional survival estimates of gastroenteropancreatic neuroendocrine tumors: A large population-based study

Given the rarity and indolent clinical course of gastroenteropancreatic neuroendocrine tumors (GEP-NETs), conditional survival might be the most suitable parameter for cancer survivors who wish to receive accurate prognostic information during follow-up. We have explored the updated incidence trend and the conditional survival of patients with GEP-NETs. Incidence trends from 2000 to 2014 were determined through an assessment of patients in the SEER cancer registry. Patients diagnosed between 1988 and 2011 were included in the conditional survival analysis, and the 3-year conditional cancer-specific survival (CCS3) was computed. The incidence of GEP-NETs, which is far higher than the incidence of many malignant tumors, is still increasing steadily (annual percentage change = 4.4). The risk of death from NETs is dynamic over time, and most deaths occur in the first 3 years after diagnosis. Patients with gastric, rectal, or appendiceal NETs hardly exhibit any excess mortality (CCS3 > 95%) given that they have already survived until a defined time-point within 10 years. The initial difference between each age group basically disappeared with an extension of the survival time since the initial diagnosis of gastric, appendiceal, or rectal NETs, but the difference persisted for tumors at other sites. Although patients with advanced-stage or higher-grade tumors have a worse survival at diagnosis than patients with early-stage or lower-grade tumors, the difference diminishes and might even disappear over time. For GEP-NETs that are rare but exhibit slow growth, clinically relevant variations in conditional survival were observed based on the time since diagnosis. Therefore, conditional survival can serve as a guideline that can be used by cancer survivors to plan their future and doctors to plan surveillance schedules.

Nomogram predicting the risk of recurrence after curative-intent resection of primary non-metastatic gastrointestinal neuroendocrine tumors: An analysis of the U.S. Neuroendocrine Tumor Study Group

BACKGROUND

The risk of recurrence after resection of non-metastatic gastro-entero-pancreatic neuroendocrine tumors (GEP-NET) is poorly defined. We developed/validated a nomogram to predict risk of recurrence after curative-intent resection.

METHODS

A training set to develop the nomogram and test set for validation were identified. The predictive ability of the nomogram was assessed using c-indices.

RESULTS

Among 1477 patients, 673 (46%) were included in the training set and 804 (54%) in y the test set. On multivariable analysis, Ki-67, tumor size, nodal status, and invasion of adjacent organs were independent predictors of DFS. The risk of death increased by 8% for each percentage increase in the Ki-67 index (HR 1.08, 95% CI, 1.05-1.10; P < 0.001). GEP-NET invading adjacent organs had a HR of 1.65 (95% CI, 1.03-2.65; P = 0.038), similar to tumors ≥3 cm (HR 1.67, 95% CI, 1.11-2.51; P = 0.014). Patients with 1-3 positive nodes and patients with >3 positive nodes had a HR of 1.81 (95% CI, 1.12-2.87; P = 0.014) and 2.51 (95% CI, 1.50-4.24; P < 0.001), respectively. The nomogram demonstrated good ability to predict risk of recurrence (c-index: training set, 0.739; test set, 0.718).

CONCLUSION

The nomogram was able to predict the risk of recurrence and can be easily applied in the clinical setting.

Long-term Outcomes of Gastroenteropancreatic Neuroendocrine Tumors

OBJECTIVES

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare but have been increasing in incidence. Limited data on the long-term outcomes of patients with these tumors are available.

METHODS

In this study, we used population-based data from the National Cancer Institute to assess long-term disease-specific survival (DSS) of patients who have undergone surgery for nonmetastatic disease. All patients with NETs of the stomach, small intestine, colon, rectum, appendix, and pancreas diagnosed between 1988 and 2009 were identified from the Surveillance, Epidemiology and End Results registry. Staging was derived from Surveillance, Epidemiology and End Results data using the European Neuroendocrine Tumor Society guidelines. Cases with incomplete staging data were excluded, along with those with stage IV disease, or those who did not undergo surgical resection.

RESULTS

Kaplan-Meier analyses were constructed to determine DSS. Analyses were further stratified according to tumor site, stage at diagnosis, and tumor grade. Overall, 13,348 patients with GEP-NETs meeting the inclusion criteria were identified.

CONCLUSIONS

There were excellent outcomes for most GEP-NET patients, with a 20-year DSS of greater than 75% across all sites and stages. Pancreatic tumors had the worst outcomes, but DSS remains greater than 50% at 20 years.

Molecular challenges of neuroendocrine tumors

Neuroendocrine tumors (NETs) are a very heterogeneous group that are thought to originate from the cells of the endocrine and nervous systems. These tumors develop in a number of organs, predominantly in the gastrointestinal and pulmonary systems. Clinical detection and diagnosis are reliable at the late stages when metastatic spread has occurred. However, traditional conventional therapies such as radiation and chemotherapy are not effective. In the majority of cases even surgical resection at that stage is unlikely to produce promising reusults. NETs present a serious clinical challenge, as the survival rates remain low, and as these rare tumors are very difficult to study, novel approaches and therapies are required. This review will highlight the important points of accumulated knowledge covering the molecular aspects of the role of neuroendocrine cells, hormonal peptides, the reasons for ectopic hormone production in NET, neuropeptides and epigenetic regulation as well as the other challenging questions that require further understanding.

Primary Site Predicts Grade for Gastroenteropancreatic Neuroendocrine Tumors

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare and abstruse neoplasms with increasing incidence and clinical relevance. The National Cancer Data Base was examined to identify GEP-NETcases from 2004 to 2013. In total, 39,454 patients diagnosed with GEP-NET were identified. Median age was 61 years. Majority was female (50.13%), white (79.49%), and had low-grade neoplasms (84.39%). On univariate analysis, age, sex, race, primary site, tumor size, and regional lymph node involvement were associated with tumor grade (P < 0.0001). On multivariate analysis, older age [odds ratio (OR) = 9.57], gender (male, OR = 1.29), and race continued to be associated with high-grade neoplasms. The primary site also remained a significant predictor of tumor grade. High-grade neoplasms were more likely to arise from the esophagus (OR = 317.75), hepatobiliary system (OR = 23.15), colorectum (OR = 14.37), ampulla of Vater (OR = 11.61), and stomach (OR = 7.84) compared with the appendix (OR = 5.41), pancreas (OR = 5.31), and small bowel (referent). The tumor grade for GEP-NETs is highly dependent on the primary site, suggesting different sites may be biologically distinct diseases. A personalized approach to GEP-NET treatment, tailored to the site of origin, is imperative.

Novel nomogram combining depth of invasion and size can accurately predict the risk for regional nodal metastases for appendiceal neuroendocrine tumors (A-NET)

INTRODUCTION

The need for regional lymphadenectomy for treating appendiceal neuroendocrine tumors (A-NET) is determined by the risk of nodal metastasis. Current guidelines for A-NET are solely based on tumor size. Methods Patients with A-NET from 1988 to 2012 were identified from the SEER registry. The depth of invasion was defined as limited to the lamina propria (LP), invading the muscularis propria (MP), and through the serosa (TS).

RESULTS

A total of 418 patients were included; the majority were female, white, and node-negative. On univariate and multivariable, the risk of nodal metastasis was associated with age, size, depth of invasion, and extent of surgery. The model predicted the likelihood of nodal metastasis, with an area under the curve of 0.89. On survival analysis, age and tumor size predicted the survival in A-NET. In a Cox regression model, they continued to predict survival. These data were utilized to create a nomogram to predict the risk of nodal metastases.

CONCLUSION

This nomogram, accurately predicts the risk of regional nodal metastases in A-NET. In addition to providing valuable information on risk for regional nodal metastases, the depth of invasion is also predictive of survival for A-NET.