Small and Large Pancreatic Neuroendocrine Tumors: a Retrospective analysis of clinicopathological features and long-term outcomes.

Description

Introduction.
Pancreatic neuroendocrine tumors (pNETs) are a heterogeneous group of neoplasms with different biological behaviours. Tumor size is a well-known predictive factor that affects management strategies and overall survival. While surgical resection is recommended for pNETs above 20 mm, the optimal approach for small pNETs remains a hot topic of debate. The aim of this study was to compare clinicopathological features and treatment results of small and large surgically resected pNET.
Materials and methods.
A retrospective cohort study was conducted on patients diagnosed with pNET between 2011 and 2024 at Riga East University Hospital. Patients were divided into two groups based on tumor size: small pNET (<20 mm) and large pNET (≥20 mm).
Results.
A total of 68 patients with pNET were identified, of whom 42 underwent surgical resection. Among them, 22 patients had small pNETs, while 20 had large pNETs. The median age was 62 years (IQR 51.8-67.5), and 80.9% of patients had hormonally nonfunctional tumors. Large pNETs were more frequently located in the head of the pancreas compared to small pNETs, respectively 45.0% vs 27.3%, p=0.124. The parenchyma- sparing approach was performed more frequently in small pNET (31.8% vs 5.0%, p=0.055), whereas PDR was more common in large pNET group (45.0% vs 13.6%, p=0.05). The rates of high-grade tumors and lymph node metastasis were higher in large pNET group. The median follow-up period was 96 months (IQR 57-125). The recurrence rate for small and large pNET group were 4.5% and 15.8%, respectively, p=0.321. The 3- and 5-year survival rates for large pNETs were 93.3% and 77.5%, respectively; while no deaths were observed in the small pNET group.
Conclusions.
Large pNETs are more aggressive, with higher probability of distant metastases and lymph node involvement. Small pNETs more often underwent parenchyma-sparing resection. These findings highlight the potential role of selective, risk-based treatment approaches for patients with small pNETs.

Period	11 Apr 2025
Event title	4th Scandinavian Baltic Pancreas Symposium
Event type	Symposium
Conference number	4
Location	Vilnius, LithuaniaShow on map
Degree of Recognition	International