Surgical strategies in MEN1 related pancreatic neuroendocrine tumors

Objective: To assess if surgery for Multiple Endocrine Neoplasia type 1 (MEN1) related non-functioning pancreatic neuroendocrine tumors (NF-pNETs) is effective for improving overall survival and preventing liver metastasis. Background: MEN1 leads to multiple early-onset NF-pNETs. The evidence base for guiding the difficult decision who and when to operate is meager. Methods: MEN1 Patients diagnosed with NF-pNETs between 1990-2014 were selected from the DutchMEN1 study group database, including >90% of the Dutch MEN1 population. The effect of surgery was estimated using time- dependent Cox analysis with propensity score restriction and adjustment. Results: Of the 152 patients, 53 underwent surgery and 99 were managed by watchful waiting. In the surgery group, tumors were larger and faster-growing, patients were younger, more often male and were more often treated in centers that operated more frequently. Surgery for NF-pNETs was not associated with a significantly lower risk of liver metastases or death, (adjusted Hazard Ratio (HR) = 0.73 (0.25 - 2.11). Adjusted HR's after stratification by tumor size were: NF-pNETs 3cm managed by watchful waiting developed liver metastases or died compared with six out of the 16 patients who underwent surgery. Conclusions: MEN1 patients with NF-pNETs 3cm, watchful waiting seems not advisable.