Minimally Invasive vs Open Left Pancreatectomy for Resectable Pancreatic Cancer: Long-Term Results of the Randomized DIPLOMA Trial

Importance: The DIPLOMA trial showed comparable radical resection rates after minimally invasive left pancreatectomy (MILP) and open left pancreatectomy (OLP) in patients with upfront resectable pancreatic cancer. Data on long-term overall survival (OS) and disease-free survival (DFS) are currently lacking, but are required before the oncological efficacy of MILP can be confirmed. Objective: To determine the long-term oncological outcome, including OS and DFS, of MILP vs OLP in patients with upfront resectable left-sided pancreatic cancer in the DIPLOMA trial. Design, Setting, and Participants: The randomized, patient-blinded and pathologist-blinded DIPLOMA trial was conducted between 2018 and 2021, with a follow-up duration of at least 36 months. It was a multicenter international trial that took place in 35 centers in 12 countries worldwide. Patients with upfront resectable pancreatic ductal adenocarcinoma of the body or tail of the pancreas were included. Interventions: Participants were randomly assigned to undergo MILP (laparoscopic and robotic) or OLP. Patients were blinded for the surgical approach. Main Outcomes and Measures: Main outcomes included OS and DFS. Other outcomes include receipt of adjuvant therapy and time to start of adjuvant therapy. Results: Between May 2018 and May 2021, 258 patients were randomized to the MILP (131 patients) and OLP (127 patients) groups. After a median follow-up of 38 (IQR 36-46) months, 134 patients (52%) had died and 127 patients (55%) experienced disease recurrence. OS did not differ significantly between the MILP and OLP groups (median, 32 vs 34 months; stratified hazard ratio, 1.02; 95% CI, 0.72-1.44; P =.92). Also, DFS did not significantly differ between the MILP and OLP groups (median, 21 vs 17 months; stratified hazard ratio, 0.96; 95% CI, 0.68-1.35; P =.81). Adjuvant therapy was administered in 79 patients after MILP (79 of 113 [70%]) and 79 patients after OLP (79 of 110 [72%]) (P =.63). Time to adjuvant therapy was comparable between groups (median 59 vs 56 days; P =.92). Conclusions and Relevance: In this long-term follow-up of the randomized DIPLOMA trial in patients with upfront resectable pancreatic cancer, oncological outcomes after MILP and OLP did not differ significantly, confirming the oncological safety of MILP.