Laparoscopic enucleation vs. pancreatectomy for small pancreatic neuroendocrine neoplasms: long-term functional and oncological outcomes

Abstract

Background: Laparoscopic surgery is being increasingly used for pancreatic neuroendocrine neoplasms (PanNENs). Although laparoscopic regular pancreatectomy (LRP) is frequently performed, laparoscopic enucleation (LE), a parenchyma-sparing technique, may be better in preserving pancreatic endocrine function. However, limited evidence is available regarding the long-term oncological and endocrine outcomes of these two laparoscopic methods. This study aimed to compare the surgical and prognostic outcomes and endocrine function preservation in patients undergoing LE and LRP for well-differentiated, non-invasive PanNEN.

Methods: This retrospective cohort study included 67 consecutive patients who underwent laparoscopic surgery for small (< 2 cm) well-differentiated PanNEN at Tohoku University Hospital between January 2001 and December 2021. LE was performed for small tumors (< 2 cm) located away (> 3 mm) from the main pancreatic duct. Clinical characteristics, surgical details, tumor characteristics, postoperative complications, recurrence-free survival (RFS), overall survival (OS), and long-term endocrine function were retrospectively analyzed. Kaplan-Meier analysis, Cox regression, and the Mann-Whitney U test were used for statistical comparisons.

Results: The median follow-up was 78.1 months for LRP and 135.4 months for LE. No significant differences were observed between the two groups in terms of the operative time, blood loss, or postoperative complications. Five-year RFS was excellent and comparable in both groups (LE, 100%, LRP 96.0%; P = 0.313). Notably, LE was associated with a significantly reduced incidence of postoperative new-onset diabetes mellitus (NODM) compared to LRP (5-year cumulative incidence: 9.1% vs. 43.2%; P = 0.0181). Multivariate analysis identified LRP (hazard ratio [HR] = 7.71, 95% confidence interval [CI]:1.03-57.8; P = 0.0469), older age (> 60 years) (HR = 4.49, 95% CI 1.62-12.4; P = 0.0039), and non-functional tumor (HR = 2.78, 95% CI 1.08-7.19; P = 0.0342) as independent predictors of NODM.

Conclusion: Given appropriate patient selection, LE of small well-differentiated PanNENs provides comparable oncological outcomes, perioperative safety, and superior long-term endocrine function preservation compared to LRP.

Keywords: Endocrine insufficiency; Laparoscopic enucleation; Laparoscopic regular pancreatectomy; Pancreatic neuroendocrine neoplasms.

Fig. 1

A Recurrence-free survival (RFS) in the laparoscopic enucleation (LE) and laparoscopic regular pancreatectomy (LRP) groups (P = 0.313). B Overall survival (OS) in the LE and LRP groups (P = 0.640). C Correlation between RFS and the WHO grade (P = 0.0046). D Correlation between RFS and the TMN clinical stage (P = 0.0002). E Correlation between RFS and lymphatic-vascular invasion

Fig. 2

Kaplan–Meier plots of incidence of new-onset diabetes mellitus after surgery. Statistical significance was assessed using the log-rank test, and 95% confidence intervals (95% CI: lower limit, upper limit) were calculated using Cox regression analysis