SRS304 - Beyond the incision: minimally invasive left pancreatectomy offers early gains without oncological compromise—a population-based analysis

Abstract Background Minimally invasive left-sided pancreatectomy (MIS-LP) is increasingly adopted for pancreatic neuroendocrine tumours (PNETs), yet its oncological safety compared with open surgery (O-LP) remains debated. Robust population-level evidence is required to guide practice. Methods Patients ≥65 years with grade 1–2 PNETs undergoing left pancreatectomy were identified from the SEER-Medicare database (2010–2019). Overall and cancer-specific survival outcomes were analysed using multilevel Cox regression after propensity-score matching (PSM). Landmark analysis from 6 months excluded early postoperative deaths. Results 772 patients were included: 257 (33%) MIS-LP and 515 (67%) O-LP. Median age was 71 years; 87% had grade 1 and 13% grade 2 tumours. Before matching, MIS-LP patients had lower comorbidity (median Charlson Index 2 versus 3, P = 0.011) and fewer with metastatic disease (2.0% versus 5.7%, P = 0.019). After PSM (MIS-LP n = 248; O-LP n = 441), 5-year overall survival was higher with MIS-LP (88.1% versus 84.5%, P = 0.03), while 5-year cancer-specific survival was similar (95.2% versus 93.5%, P = 0.11). O-LP was associated with increased risk of death (HR 1.75, 95% c.i. 1.05–2.91, P = 0.030), though not cancer-specific death (HR 1.97, 95% c.i. 0.86–4.54, P = 0.110). Notably, all 90-day mortalities (n = 15, 1.9%) occurred in the O-LP group. In landmark analysis beyond 6 months, surgical approach was no longer predictive of OS or CSS. Conclusions MIS-LP confers an early survival advantage, driven by reduced perioperative mortality, without compromising long-term oncological outcomes. As the largest population-based analysis in this setting, these findings support MIS-LP as the standard surgical approach for older patients with low- to intermediate-grade PNETs.