Head and body/tail pancreatic neuroendocrine tumors have different biological characteristics and clinical outcomes.
PURPOSE
The incidence of pancreatic neuroendocrine tumors (pNETs) has continued to increase, but for pNETs, there is still no distinction between treatments based on anatomical location. We aim to determine whether NETs located at the head and body/tail of the pancreas are different.


PATIENTS AND METHODS
Within the Surveillance, Epidemiology, and End Results database (2004-2016), we focused on pNETs patients with comprehensive information. The patients were divided into two groups based on tumors' location. We compared the characteristics of the two groups and assessed the risk factors for lymphatic metastasis. Survival analysis was performed based on the biological characteristics of the tumor.


RESULTS
In all 3011 patients, pNETs were more common in the body/tail (62.94%) than in the head (37.06%) of the pancreas. The risk factors for lymph node metastasis in the two groups were different. Nonmetastatic, low-grade pancreatic body/tail NETs had the best prognosis (p < 0.001). For low-grade tumors (G1-G2), lymphatic metastasis did not significantly affect the prognosis of patients with pancreatic head NETs (p = 0.098) but affected the overall survival of patients with pancreatic body/tail NETs (p < 0.001). The tumors at the pancreatic head were larger (p = 0.001), more likely to have positive lymph nodes (p < 0.001) and more prone to locally advanced and distant invasion (p < 0.001). The prognosis of pancreatic head NETs 21-40 mm was worse than that of body/tail pNETs (p < 0.001). For non-functional NETs, the overall survival of pancreatic body/tail tumors was better (p < 0.001).


CONCLUSION
The pancreatic head and pancreatic body/tail NETs have different biological characteristics and clinical outcomes and they should be treated differently.
['Mei|Wentong|W|', 'Ding|Yixuan|Y|', 'Wang|Shuo|S|', 'Jia|Yuchen|Y|', 'Cao|Feng|F|', 'Li|Fei|F|http://orcid.org/0000-0002-0532-9054']
D000368:Aged D005260:Female D006801:Humans D008207:Lymphatic Metastasis D008297:Male D008875:Middle Aged D018358:Neuroendocrine Tumors D010190:Pancreatic Neoplasms D012189:Retrospective Studies D012307:Risk Factors D018426:SEER Program D016019:Survival Analysis
Pancreatic neuroendocrine tumors Clinical outcomes Prognosis Tumor biological characteristics