Surgical outcomes of gastro-entero-pancreatic neuroendocrine tumors G3 versus neuroendocrine carcinoma

Retrospective analysis of criteria for oncological completion surgery of neuroendocrine tumors of the appendix

PURPOSE

Neuroendocrine neoplasms of the appendix (aNET) are rare tumors that are often diagnosed by pathology as an incidental finding after appendectomy for acute appendicitis. Several guidelines proposed risk criteria to indicate oncological completion surgery after appendectomy. The aim of this study was to evaluate the reliability of proposed criteria for completion surgery of aNET.

METHODS

Patients with aNET treated at ENETS center of excellence Marburg between 2002 and 2022 were retrieved from a prospective data base. Demographic data, histopathological findings, including formerly proposed criteria to indicate oncological completion surgery, histological results of the completion resection and disease-free survival were evaluated.

RESULTS

82 patients with a median age of 35 (range 8-82) years were analysed. 72 (88%) patients underwent an emergency appendectomy because of acute appendicitis. 11 (13%) patients received an ileocecal resection or right hemicolectomy. Seven (8.5%) patients had lymph node metastases and three (3.6%) patients had distant metastases at the initial operation. 27 (33%) patients underwent completion surgery by right hemicolectomy according to guideline criteria, but postoperative histology detected lymph node and distant metastases in only six (22%) and zero patients resulting in an overtreatment of 21 (75%) patients. A tumor size of > 2 cm was the only significant criterion which was associated with lymph node metastases (p < 0.05). After a median follow-up of 62 months (range 2-264) 76 (96%) of the patients in stages I to III were alive with no evidence of disease.

CONCLUSION

aNET have an excellent prognosis in stages I-III and distant metastases are rare. Formerly proposed criteria for oncological completion surgery have to be adopted and discussed for every patient, as they might result in an overtreatment in at least 75% of patients.

Preoperative Glycosylated Hemoglobin A1C Impacts Long-Term Outcomes Following Curative-Intent Resection of Nonfunctional Gastroenteropancreatic Neuroendocrine Tumors

BACKGROUND

To investigate the impact of preoperative glycosylated hemoglobin A1C (HbA1c) among patients following curative-intent resection of nonfunctional gastroentropancreatic neuroendocrine tumors (GEP-NETs).

METHODS

Patients who underwent curative-intent resection for GEP-NETs from 2000 to 2020 were identified from the US Neuroendocrine Tumor Study Group (US-NETSG). Preoperative blood HbA1c levels were defined as high HbA1c (≥ 6.5%) versus low HbA1c group (< 6.5%). Impact of HbA1c level on postoperative short-term and long-term overall (OS) were investigated.

RESULTS

A total of 130 patients with HbA1c < 6.5% and 60 patients with HbA1c ≥ 6.5% were included. Patients with HbA1c ≥ 6.5% had higher proportion of comorbidities, such as hypertension, obesity, anemia, and lower preoperative albumin levels versus patients with HbA1c < 6.5% (all p < 0.05). In addition, high level of preoperative HbA1c was associated with increased incidence of wound and infectious complications, as well as decreased long-term OS (median OS: high Hb1Ac 89.8 months vs. low Hb1Ac not reached, HR 3.487, p = 0.004) among patients with nonfunctional GEP-NETs, as well as among the subset of pancreatic NET patients (median OS: high Hb1Ac 74.3 months vs. low Hb1Ac not reached, p = 0.004), and patients with normal fasting blood glucose (< 140 mg/dL) (median OS: high Hb1Ac 75.4 months vs. low Hb1Ac not reached, p = 0.001).

CONCLUSIONS

Hb1Ac might have value as a screening tool to identify high-risk patients following surgical resection of nonfunctional GEP-NETs for consideration of more strict postoperative surveillance and treatment of elevated Hb1Ac level.

Low Prognostic Nutritional Index Is Common and Associated with Poor Outcomes following Curative-Intent Resection for Gastro-Entero-Pancreatic Neuroendocrine Tumors

INTRODUCTION

To investigate the impact of prognostic nutritional index (PNI) on short- and long-term outcomes of patients who underwent curative-intent resection for gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs).

METHODS

Patients with GET-NETs who underwent curative-intent resection were identified from a multi-center database. The prognostic impact of clinicopathological factors including PNI on post-operative outcomes were evaluated. A novel nomogram was developed and externally validated.

RESULTS

A total of 2,099 patients with GEP-NETs were included in the training cohort; 255 patients were in the external validation cohort. Median PNI (n = 973) was 47.4 (IQR 43.1-52.4). At the time of presentation, 1,299 (61.9%) patients presented with some type of clinical symptom. Low-PNI (≤42.2) was associated with gastrointestinal symptoms, as well as nodal metastasis and distant metastasis (all p < 0.05). Patients with a low PNI had a higher incidence of severe (≥Clavien-Dindo grade IIIa: low PNI 24.9% vs. high PNI 15.4%, p = 0.001) and multiple (≥3 types of complications: low PNI 14.5% vs. high PNI 9.2%, p = 0.024) complications, as well as a worse overall survival (OS)(5-year OS, low PNI 73.7% vs. high PNI 88.5%, p < 0.001), and RFS (5-year RFS, low PNI 68.5% vs. high PNI 79.8%, p = 0.008) versus patients with high PNI (>42.2). A nomogram based on PNI, tumor grade and metastatic disease demonstrated excellent discrimination and calibration to predict OS in both the training (C-index 0.748) and two external validation (C-index 0.827, 0.745) cohorts.

CONCLUSIONS

Low PNI was common and associated with worse short- and long-term outcomes among patients with GEP-NETs.

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.

A systematic review of therapeutic strategies in gastroenteropancreatic grade 3 neuroendocrine tumors

Background

Gastroenteropancreatic (GEP) neuroendocrine neoplasms with Ki-67 > 20% were subdivided in the most recent 2019 World Health Organization histopathological classification into grade 3 (G3) neuroendocrine tumors (NETs), described as well-differentiated tumors, and neuroendocrine carcinomas, which are described as poorly differentiated tumors. This classification met the demand noted for different prognoses between these subgroups, prompting the need for treatment recommendations for well-differentiated G3 tumors.

Methods

We systematically searched medical literature databases and oncology conferences for studies on G3 GEP NET to describe epidemiology, diagnosis, molecular features, and treatments used. We excluded studies that did not discriminate G3 NET data. Data were tabulated and described, and a quality analysis of the reports was performed.

Results

We found 23 published studies and six abstracts; 89.7% of studies were retrospective, six were composed exclusively of G3 NETs. Among 761 patients, the median number of patients per study was 15, most were male and older than 60 years, and functional imaging tests were positive in more than 80% of cases. Overall, the scientific evidence supporting the treatment of G3 GEP NETs is limited. For localized disease, resection remains the standard treatment but there is no evidence to support neoadjuvant or adjuvant therapy. For advanced disease, capecitabine and temozolomide seems to be the most effective option, with a response rate, median progression-free survival, and median overall survival up to 37.9%, 20.6 months, and 41.2 months, respectively.

Conclusion

The latest available data on the epidemiology, diagnosis, molecular changes, and treatment of G3 GEP NET are described. Yet, the level of evidence for treatment recommendations is low, as most studies are retrospective. A treatment algorithm for G3 GEP NET is proposed.