Determining lymph node metastasis and dissection and following prognosis in pancreatic neuroendocrine tumors: risk prediction using preoperative factors.

Background: The clinical significance of lymph node (LN) dissection in pancreatic neuroendocrine tumors (pNETs) remains unclear. This study aimed to identify preoperative risk factors associated with LN metastasis and prognosis, and to assess the need for LN dissection by risk stratification.

Methods: Total 287 patients with pNETs who underwent surgery at a tertiary center (2010-2022) were retrospectively analyzed. Clinicodemographic and preoperative variables were used to stratify patients and assess their impact on survival and LN metastasis.

Results: Among 274 evaluable patients, 21 had LN metastases, 87 had no metastases, and 166 did not undergo LN dissection. Tumor location, prominent LN, and suspected distant metastasis were predictors of LN metastasis. Age >70, tumor ≥2 cm, enlarged LN, and distant metastases were associated with overall survival. Survival differed significantly according to the risk factors (P<0.001). Patients with 0-1 factor had low LN metastasis (9.5 %) and showed no survival difference according to LN dissection. Those with ≥2 factors had higher LN metastasis (41.2 %), but LN dissection/metastasis status did not significantly affect survival.

Conclusion: Risk stratification using preoperative factors can inform surgical decisions in pNETs. LN dissection may be omitted in low-risk patients, while high-risk cases require accurate staging and postoperative planning.