Survival and prognostic differences between appendiceal NETs and goblet cell adenocarcinomas.

Area of Science:

• Gastroenterology
• Oncology
• Pathology

Background:

• Appendiceal neuroendocrine tumors (aNETs) generally have an excellent prognosis.
• Appendiceal goblet cell adenocarcinomas (aGCAs), previously termed goblet carcinoid tumors, share features with aNETs, leading to diagnostic confusion.
• Discrepancies in prognostication studies highlight the need to differentiate between aNETs and aGCAs.

Purpose of the Study:

• To investigate the distinct disease courses of aNETs and aGCAs.
• To clarify inconsistencies in the literature regarding the prognostication of these appendiceal tumors.
• To identify key variables influencing recurrence and survival in patients with aNETs and aGCAs.

Main Methods:

• Retrospective analysis of patients diagnosed with aNET or aGCA between 2000 and 2019.
• Kaplan-Meier survival analysis to assess progression-free survival (PFS) and disease-specific survival (DSS) for both tumor types independently and combined.
• Cox regression analysis to identify prognostic factors for PFS and DSS.

Main Results:

• Patients with aNETs demonstrated high 5- and 10-year PFS (98%) and DSS (100% and 96%).
• In contrast, aGCAs had significantly lower 5- and 10-year PFS (57% and 30%) and DSS (77% and 58%).
• Peritoneal metastases worsened DSS (P < 0.001), and WHO grade 3 in aGCAs was linked to poorer PFS and DSS.

Conclusions:

• aNETs and aGCAs are distinct entities with markedly different prognoses.
• Previous studies may have misclassified aggressive aGCAs as aNETs, contributing to literature inconsistencies.
• Accurate tumor classification and adherence to updated nomenclature are essential for precise prognostication and patient management.