A new scoring system to predict recurrent disease in grade 1 and 2 non-functional pancreatic neuroendocrine tumors

Abstract

Background: Urgical resection is the preferred treatment for non-functioning pancreatic neuroendocrine tumors (NF-pNET), however recurrence still occurs frequently after curative surgery, worsening prognosis of patients. We present the recurrence-score to predict recurrence after curative resection of NF-pNET. Methods: Retrospectively patients with grade 1 or 2 NF-pNET without distant metastases or hereditary syndromes were included. Local or distant tumor recurrence was scored. The recurrence-score was developed using independent predictors for recurrence to predict recurrence within 5-years after curative resection. Results: With a median follow-up of 51 months, 211 patients were included. Thirty-five patients (17%) developed recurrence. The 5- and 10-year disease specific/overall survival was 98%/91% and 84%/68%, respectively. Predictors for recurrence were tumor grade 2, lymph node metastasis, and perineural invasion. With these predictors, the recurrence-score was made. Discrimination (c-statistic 0.81) and calibration (Hosmer Lemeshow Chi-square p=0.258) indicated that the ability to identify patients at risk for recurrence is good. Conclusion: The recurrence-score could predict recurrence after curative resection of grade 1 and 2 NF-pNET. A less extensive follow-up could be proposed for patients with low recurrence-risk. For high-risk patients clinical trials should be initiated to investigate whether adjuvant therapy might be beneficial.