Mapping of lymph node metastasis in nonfunctional pancreatic neuroendocrine tumors: A retrospective analysis of 455 patients.

BACKGROUND/

OBJECTIVES

Radical surgery is the standard treatment for resectable pancreatic neuroendocrine tumors (pNETs), but the necessity and extent of lymphadenectomy remain controversial. This study aimed to identify the optimal extent of lymph node dissection based on metastasis incidence.

METHODS

A retrospective review of 955 patients treated at Shanghai Cancer Center, Fudan University, identified 455 patients who underwent lymph node dissection.

RESULTS

For tumors ≤2 cm, lymph node metastases were observed at stations 13 & 17 (6.25 %) for tumors in the pancreatic head, and at station 8 (5.71 %) and stations 11 & 18 (4.62 %) for tumors in the body-tail. For tumors 2-4 cm, stations 13 & 17 (20.27 %) and station 14 (12.25 %) were most frequently positive in the head group, while station 11 & 18 (17.20 %) and station 14 (13.64 %) were positive in the body-tail group. For tumors ≥4 cm in the body-tail group, metastases were highest at stations 11 & 18 (24.00 %), station 8 (22.73 %), and station 10 (14.29 %). Insufficient data prevented analysis of tumors ≥4 cm in the head group. Subgroup analyses by tumor grade were also conducted.

CONCLUSIONS

Lymph node metastases are uncommon in pNETs <2 cm, supporting observation with close follow-up as an alternative to routine surgery. For tumors >2 cm, lymphadenectomy should be tailored to metastasis risk at specific stations.