1. Neoadjuvant treatment (NAT) is increasingly used in managing pancreatic ductal adenocarcinoma (PDAC), necessitating dependable methods to evaluate tumor response.
2. Among various pathological tumor regression grading systems, the College of American Pathologists (CAP) system is commonly used to predict chemo-responsiveness and survival.
3. This study aimed to analyze long-term survival outcomes based on pathologic response using the CAP grade after NAT in PDAC and to identify clinicopathologic factors that influence a favorable pathologic response.

Inclusion Criteria:

• Adult patients (aged >18 years) who underwent pancreatic resection after NAT at a single center between January 2009 and December 2023.
• Patients were initiated on NAT after confirming PDAC diagnosis based on pathological examination.

Exclusion Criteria:

• Patients without a reported CAP grade
• Patients who underwent palliative surgery
• Patients who received NAT outside the specified protocol due to incomplete information.

All consecutive adult patients (aged >18 years) who underwent pancreatic resection after NAT at Seoul National University Hospital between January 2009 and December 2023 were included. Patients were initiated on NAT after confirming PDAC diagnosis based on pathological examination.