Appendiceal Neuroendocrine Tumors: Does Colon Resection Improve Outcomes?

Surgical Treatment of Neuroendocrine Tumors of the Terminal Ileum or Cecum: Ileocecectomy Versus Right Hemicolectomy

BACKGROUND

Simple ileocecectomy and right hemicolectomy are two potential operative approaches to treat patients with neuroendocrine neoplasm in the terminal ileum and/or cecum (IC-NENs). We sought to define the long-term outcome of patients undergoing ileocecectomy versus right hemicolectomy for IC-NENs, as well as characterize number of nodes evaluated and lymph node metastasis (LNM) associated with each procedure.

METHODS

Patients who underwent curative-intent resections for IC-NENs between 2000 and 2016 were identified from a multi-institutional database. The clinicopathologic characteristics, surgical procedures, and the overall (OS) and recurrence-free survival (RFS) were compared among patients who underwent formal right hemicolectomy versus ileocecectomy only.

RESULTS

Among 127 patients with IC-NENs, median size of the largest tumor size was 2.0 (IQR 1.2-2.9) cm; 35 (27.6%) patients had multiple lesions. At the time of surgery, 93 (73.2%) patients underwent a right hemicolectomy, whereas 34 (26.8%) had ileocecectomy only. Every patient had a lymph node dissection (LND) with a median number of 16 (IQR 12-22) nodes evaluated. A majority (n = 110, 86.6%) of patients had LNM with a median number of 3 (IQR 2-5) LNM. Patients who underwent hemicolectomy had more lymph nodes evaluated versus patients who had an ileocecectomy only (median, 18 vs. 14, p = 0.004). Patients who underwent formal right hemicolectomy versus ileocecectomy had a similar OS (median OS, 101.9 vs. 144.5 months, p = 0.44) and RFS (median RFS, 70.3 vs. not attained, p = 0.80), respectively.

CONCLUSIONS

Ileocecectomy had similar long-term outcomes versus right hemicolectomy in treatment of IC-NENs despite a difference in the lymph node harvest.

Survival Profile and Prognostic Factors for Appendiceal Mixed Neuroendocrine Non-neuroendocrine Neoplasms: A SEER Population-Based Study

Introduction

Mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) is a rare form of neuroendocrine neoplasms (NENs). The purpose of this study was to investigate the characteristics and survival profile of appendiceal MiNENs, with a view of providing robust clinical features of this rare disease.

Methods

Patients were selected from the Surveillance, Epidemiology, and End Results database (2004–2016). The prognosis of MiNEN (n = 315) was compared with other histological subtypes including neuroendocrine tumor (NETs) (n = 1734), neuroendocrine carcinoma (NECs) (n = 375), goblet cell carcinoid (GCC) (n = 968), signet ring cell carcinoma (n = 463), mucinous adenocarcinoma (MAC) (n = 2355), and non-mucinous adenocarcinoma (NMAC) (n = 1187) in the appendix. Age-adjusted incidence was calculated using Joinpoint regression. The Cox proportional hazards model and the Fine–Gray competing risk model were used to perform overall survival (OS) and cancer-specific mortality (CSM) analyses, respectively.

Results

The age-adjusted incidence of MiNENs increased from 0.01/100,000 person-years in 2004 to 0.07/100,000 person-years in 2016. The 3-, 5-, and 10-year OS rates for MiNENs were 69.5, 57.4, and 43.7%, respectively, and the corresponding CSM rates were 23.1, 36.4, and 45.1%, respectively. Multivariate analysis revealed that the prognosis of MiNENs was worse than that of NETs, NECs, GCC, and MAC but better than that of NMAC and signet ring cell carcinoma. Tumor extension was the only independent factor influencing the prognosis of MiNENs, but tumor size, grade, and surgical approaches were not. Moreover, when compared with local excision or appendectomy, extensive surgery such as hemicolectomy or colectomy did not prolong the survival of individuals with MiNENs.

Conclusion

MiNEN is a rare but aggressive tumor with a poor prognosis differing from NENs, GCC and adenocarcinomas. To improve the prognosis of the disease, early diagnosis and comprehensive evaluation are necessary.

A 30-Year Long-Term Experience in Appendix Neuroendocrine Neoplasms-Granting a Positive Outcome

Neuroendocrine neoplasms (NENs) are the most common tumor of the appendix and have an excellent prognosis. Appendiceal tumors diagnosed between 1989 and 2019 were reviewed, and clinical data were collected from patient files. Part of the series was immuno-profiled for markers related to cell cycle proliferation and/or senescence-type, apoptotic, and metastatic potential. Appendix NENs were detected in 74 patients, with 0.47% of incidence per appendectomy. The median age of the patients was 21.5 years, with two age peaks of incidence at 17.0 and 55.2 years. The median tumors size was 5.8 mm, and most were smaller than 10 mm. Lymphovascular and perineural invasion, as well as necrosis, was associated with larger tumor size. G1 tumors composed 96.0% of the cohort. The presence of moderate/strong p16 and the absent/low Bcl-2 expression was frequently observed and associated with a smaller size. This study represents one of the largest cohorts and with a long follow-up. For tumors smaller than 10 mm appendicectomy was sufficient as a curative procedure, as revealed by the good outcome. This series presented a 100% disease-free survival. The indolent phenotype of appendix NENs is supported by the expression of markers that point towards a strong inhibition of cell replication and growth inhibition.