Neoadjuvant chemotherapy with gemcitabine and S-1 significantly improves survival for patients with resectable pancreatic ductal adenocarcinoma compared to upfront surgery.

• Median overall survival: 37.0 months (nac-gs) vs. 26.6 months (ups); hazard ratio for mortality: 0.73.
• Median relapse-free survival: 14.3 months (nac-gs) vs. 11.3 months (ups); hazard ratio for relapse: 0.77.

Consider neoadjuvant therapy in surgical planning to enhance patient outcomes.