Somatostatin analogs for resectable pancreatic neuroendocrine tumors in high-risk surgical patients: Data from a single-center cohort

Objectives To evaluate the use of long-acting somatostatin-analogs (SSA) for treating non-advanced, resectable pancreatic neuroendocrine tumors (PNETs) with indications to surgery, in high-risk patients who were not candidates for surgery. Methods Patients diagnosed with histology-proven, non-advanced G1/low-G2 68Ga-TC/PET-positive PNETs >20 mm who did not undergo surgery due to comorbidities/old age/high-risk surgical profile, which were treated with SSA at a single, high-volume institution were included. The efficacy of SSA was evaluated using the analysis of tumor growth rate (TGR). “Negative TGRTx-TpreSSA” was defined as the first time point after the initiation of SSA when a negative TGRTx-TpreSSA was observed. Results Between 2014-2024, 20 patients were treated with long-acting SSA. The median age was 76 (IQR 72-80), and the median ASA score was 3 (IQR 3-3). Fifteen patients (75%) received Lanreotide, and five (25%) octreotide acetate (Sandostatin® LAR). The median overall survival was 68.5 months (IQR 60-99). In four patients (20%), SSA were interrupted when the tumor had shrunk below 2 cm. In one of them, SSA reintroduction was necessary due to disease progression (after 14 months). In two patients (10%), the treatment was interrupted due to side effects. In one of these, the disease progressed until death at 87 years old. At the last follow-up, sixteen patients were alive, 3 had died (1 death of disease), and 13 were receiving SSA. T2 PNETs presented a significantly faster response to SSA therapy compared to T3 (Median time to “Negative TGRTx-TpreSSA”: 6 [95% CI 5, na] vs 52 [95% CI 19, na] months, respectively; p=0.0092) Conclusion In patients at high surgical risk, with localized, resectable, G1 or low-G2, 68Ga-TC/PET-positive PNETs >20 mm, SSA can obtain disease control with a manageable safety profile.