Identifying Risk Factors and Patterns for Early Recurrence of Pancreatic Neuroendocrine Tumors: A Multi-Institutional Study.

Background: Identifying patients at risk for early recurrence (ER) following resection for pancreatic neuroendocrine tumors (pNETs) might help to tailor adjuvant therapies and surveillance intensity in the post-operative setting.
Methods: Patients undergoing surgical resection for pNETs between 1998-2018 were identified using a multi-institutional database. Using a minimum p -value approach, optimal cut-off value of recurrence-free survival (RFS) was determined based on the difference in post-recurrence survival (PRS). Risk factors for early recurrence were identified.
Results: Among 807 patients who underwent curative-intent resection for pNETs, the optimal length of RFS to define ER was identified at 18 months (lowest p -value of 0.019). Median RFS was 11.0 months (95% 8.5-12.60) among ER patients ( n = 49) versus 41.0 months (95% CI: 35.0-45.9) among non-ER patients ( n = 77). Median PRS was worse among ER patients compared with non-ER patients (42.6 months vs. 81.5 months, p = 0.04). On multivariable analysis, tumor size (OR: 1.20, 95% CI: 1.05-1.37, p = 0.007) and positive lymph nodes (OR: 4.69, 95% CI: 1.41-15.58, p = 0.01) were independently associated with ER.
Conclusion: An evidence-based cut-off value for ER after surgery for pNET was defined at 18 months. These data emphasized the importance of close follow-up in the first two years after surgery.