AB018. S018. The prognostic impact of primary tumor resection in pancreatic neuroendocrine tumors with synchronous multifocal liver metastases

Background: Whether primary tumor resection benefits patients with synchronous multifocal liver metastases from pancreatic neuroendocrine tumors remains controversial. We investigated whether primary tumor resection significantly affects survival in this study.

Methods: A retrospective study of patients with synchronous multifocal liver metastases from pancreatic neuroendocrine tumors between 1998 and 2016 was performed. Patient demographics, operation details, adjuvant treatment, and pathological and survival information were collected, and relevant clinical-pathological parameters were assessed in univariate and multivariate survival analyses.

Results: Sixty-four patients were included in this study, including 35 patients who underwent primary tumor resection. For the patients who did not undergo primary tumor resection, treatment consisted of observation, octreotide administration, and/or systemic chemotherapy. The median survival time and 5-year survival rate of this cohort were 50 months and 45.8%, respectively. Median survival time in the resected group was significantly longer at 72 months than that of 32 months in the non-resected group (P=0.021). Multivariate analysis showed that primary tumor surgery was a significant independent prognostic factor (HR =0.368; 95% CI: 0.142–0.949; P=0.039).

Conclusions: Primary tumor resection significantly benefits patients with synchronous multifocal liver metastases from pancreatic neuroendocrine tumors. However, this treatment option should be individually evaluated for each patient and should become a part of the integrated therapeutic strategy according to the clinician’s judgement.