Real-world effectiveness of adjuvant octreotide therapy in patients with pancreatic neuroendocrine tumors at high recurrence risk: A multicenter retrospective cohort study

Adjuvant therapy for pancreatic neuroendocrine tumors (PanNETs) after radical resection lacks evidence-based data and remains controversial. This study aimed to validate whether long-acting octreotide is a potential candidate for adjuvant therapy in patients with G2 PanNETs at high recurrence risk by clustering real-world data. A retrospective review of patients with nonmetastatic grade 2 PanNETs who underwent radical resection at six research centers between 2008 and 2020 was conducted. Propensity score matching and inverse probability of treatment weight analysis were used to control confounding factors. Overall, 357 patients (octreotide group, n = 82; control group, n = 275) were analyzed. Kaplan-Meier survival analyses showed that the octreotide group had longer disease-free survival (DFS) compared with the control group (36 months: 93.3% vs. 79.0%, p = .0124; 60 months: 71% vs. 67.6%, p = .0596, respectively), as well as overall survival (OS) (60 months: 98% vs. 83.8%, p = .0117, respectively). Multivariate analyses indicated that octreotide long-acting repeatable (LAR) adjuvant therapy was associated with higher OS (p = .0270) at 60 months. Propensity score matching analysis showed that octreotide adjuvant therapy was associated with higher DFS (p = .0455) and OS (p = .0190) at 60 months. Similar results were obtained via inverse probability of treatment weight analysis. Subgroup analysis indicated that octreotide LAR was associated with a high DFS in patients with lymph node metastasis or Ki-67 <10% PanNETs. Adjuvant therapy with long-acting octreotide following radical resection of nonmetastatic G2 PanNETs may be associated with improved DFS and OS in a real-world setting.