Clinical outcomes of medical therapy, EUS-guided ethanol ablation, and surgical resection in insulinoma: a clinical epidemiology study.

INTRODUCTION

Insulinoma is a rare pancreatic neuroendocrine tumor causing hypoglycemia. Surgery is the standard treatment, while endoscopic ultrasound (EUS)-guided ethanol ablation and medical therapy are alternatives in some patients.

METHODS

In this retrospective study, we recruited 19 patients with insulinoma treated between 2011 and 2025 at National Taiwan University Hospital. The final treatment strategies were surgery (n = 13), EUS-guided ethanol ablation (n = 3), and medical therapy (n = 3). The study outcomes included post-procedure stays (PPS), treatment-related complications, and follow-up results. New-onset diabetes and complete remission rates for insulinoma were examined and compared across treatment modalities. A Firth's bias-reduced logistic regression analysis was performed to identify predictors of complete remission in 19 patients with insulinoma.

RESULTS

Patients could receive more than one treatment. Among the three final treatment modalities, surgical resection achieved the highest complete remission rate (13/13; 100%) but was associated with a longer PPS (mean ± standard deviation [SD] = 13.46 ± 7.59 days) and a higher incidence of new-onset diabetes (2/13, 15.38%). EUS-guided ethanol ablation demonstrated moderate efficacy (2/3; 66.67%) with a comparable PPS (18.33 ± 27.43 days). Lastly, medical therapy relieved symptoms but yielded no complete remissions in insulinoma (0/3; 0%). Paradoxical hypoglycemia occurred in 2 of 8 patients (25.0%) during octreotide testing or after direct octreotide treatment. One patient with insulin autoimmune syndrome improved after drug withdrawal and multimodal therapy. Logistic regression analysis identified a positive linear effect of baseline glucose levels (mg/dL) on insulinoma complete remission (estimated adjusted odds ratio [aOR] = 1.2140, p = 0.0461) and ever surgery (yes vs. no) as the most effective treatment for complete remission in insulinoma (aOR = 296.0707, p = 0.0015).

CONCLUSION

Although surgery was the most effective treatment, it was associated with longer recovery times and potential metabolic risks. EUS-guided ethanol ablation provided a less invasive alternative with a moderate success rate, whereas medical therapy primarily offered symptomatic control rather than a definitive complete remission. Notably, lower baseline glucose levels were associated with treatment resistance, suggesting a potential role in guiding individualized therapeutic strategies.