Management and Surveillance of Non-Functional Pancreatic Neuroendocrine Tumors: Retrospective Review

BACKGROUND:/Objective. To determine the outcomes of a non-operative management approach for sporadic, small, non-functional pancreatic neuroendocrine tumours.METHODS:A retrospective chart review of patients with non-functional pancreatic neuroendocrine tumours initially managed non-operatively at a single institution was performed. Patients were identified through a search of radiologic reports, and individuals with ≥2 cross-sectional imaging studies performed >6 months apart from Jan. 1, 2000 to Dec. 31, 2013 were included. Data on tumour size, radiologic characteristics at diagnosis, interval radiologic growth, and surgical outcomes were recorded.RESULTS:Over the thirteen-year study period, 95 patients met inclusion criteria and were followed radiologically for a median of 36 months (18-69 months). Median initial tumour size on first imaging was 14.0 mm (IQR 10-19 mm). Median overall tumour growth rate was 0.03 mm/month (IQR: 0.00-0.14 mm/month). There was no significant relationship between initial tumour size and growth rate for tumours ≤ 2 cm or for lesions between 2 and 4 cm. Thirteen (14%) patients initially managed non-operatively underwent resection during the follow-up period. Reasons for surgery included interval tumour growth, patient anxiety or preference, or diagnostic uncertainty. Median time to surgery was 14 months (IQR 8-19 months). No patients progressed beyond resectability or developed metastatic disease during the observation period.CONCLUSION:For patients with sporadic, small, non-functional pancreatic neuroendocrine tumours, radiologic surveillance appears to be a safe initial approach to management.