The analysis of prognostic value of liver metastatic burden for non-functional pancreatic neuroendocrine tumors with synchronous liver metastasis after curative surgery: a retrospective study in a single center

Background: Pancreatic neuroendocrine tumors (pNETs) with synchronous liver metastasis (NELM) are associated with poor prognosis. Radical surgery is the only curative treatment option for these patients. However, the prognostic indicators for NELM patients who underwent radical surgery remain unclear. This study aimed to evaluate the prognostic value of liver metastasis burden (LMB) and other general clinicopathological indicators in patients who underwent radical resection. Methods: A retrospective analysis was conducted on a cohort of 36 patients who underwent surgery between January 2016 and December 2023. The LMB indicator was defined as the ratio of metastatic volume to liver volume (RML). The optimal cutoff value of RML was identified via X-tile software, dividing the population into high and low groups. Results: Kaplan-Meier (KM) curves for progression-free survival (PFS) revealed a significant difference between high and low groups of RML ( P = .004), but there were no statistical differences in overall survival (OS) between the 2 groups ( P = .309). Cox regression univariable analysis indicated that only high RML was associated with poor PFS (hazard ratio = 4.42, 95% confidence interval = 1.48–13.22; P = .008). However, it was not significantly associated with OS ( P = .331). High RML emerged as an independent risk factor for PFS in these patients (hazard ratio = 4.73, 95% confidence interval = 1.59–14.03; P = .005). In the high RML group, patients receiving preoperative chemotherapy or chemotherapy plus somatostatin analogs (SSA), had lower recurrence rates compared with those without chemotherapy or without chemotherapy plus SSA, respectively. No such benefit was observed in the low RML group. Conclusion: RML may serve as an effective prognostic indicator of PFS for patients with NELM who undergo curative surgery. For these patients with high liver metastatic burden, preoperative treatment regimens containing chemotherapy should be recommended.