A wait-and-watch approach to small pancreatic neuroendocrine tumors: prognosis and survival.

Background: Whether all the small (ø≤20mm) non-functional pancreatic neuroendocrine neoplasms (pNENs) should be routinely resected is unclear.
Aim: To assess the overall survival (OS) and progression-free survival (PFS) of patients with small pNENs, followed-up with different management options.
Material and Methods: Between 2007-2014, 51 patients were newly diagnosed with pNEN. 15 patients with pNENs ø ≤20 mm underwent an intensive follow-up at 3-month intervals during the first year and then every 6 months (FU pNEN group). They were all at TNM stage I, except for one patient at stage IIA. 21 patients underwent surgical resection (SR pNEN group): 2 patients were at TNM stage I, 9 IIA, one IIIB, 9 IV. 15 patients received systemic therapy (ST pNEN group) due to advanced disease or contraindications to surgery: 5 were at stage IIA, 2 IIB, 8 IV.
Results: The median follow-up for the entire cohort was 50 months. Survival was similar in the FU and SR pNEN groups, but significantly worst in the ST pNEN patients (log-rank test P <0.05). The 4-year survival rate was 100% in the FU pNEN group, 90.5% among the SR pNEN patients, 61% for the ST pNEN ones (p <0.0001). The disease remained stable in all but one patient in the FU pNEN group, whereas six patients in the SR group and five in the ST group showed disease progression.
Conclusions: The "wait-and-watch" approach to early-stage small pNENs appears to be safe although further studies are needed to confirm these results in larger cohorts of patients.