Clinical Significance of an R1 Resection for Pancreatic Ductal Adenocarcinomas Treated by Intensive FOLFIRINOX...

This study assessed the prognostic significance of an R1 resection after intensive FOLFIRINOX (FX) neoadjuvant chemotherapy in patients with borderline (BL) and locally advanced pancreatic ductal adenocarcinomas.

We retrospectively analyzed data collected from January 2010 through December 2024 at a single center.

A total of 219 consecutive patients (31 borderline and 188 locally advanced) underwent resection for pancreatic ductal adenocarcinoma after induction FX chemotherapy; the median number of preoperative cycles was 11 (range: 2-26). Venous resection was present in 191 patients (87.7%) and arterial resection in 141 patients (64.4%). R1 resection was observed in 73 patients (33.4%). The median overall survival (OS) from surgery was 30 months (95% confidence interval [CI] 21.3-38.6), with 1-, 3-, and 5-year survival rates of 77%, 45%, and 32%, respectively. R1 resection (hazard ratio [HR] 1.47; 95% CI 1.01-2.14; p = 0.004) was identified as an independent prognostic factor for OS, along with normalization of carbohydrate antigen 19-9 before surgery (HR 0.68; 95% CI 0.47-0.99; p = 0.04) and positive lymph nodes (HR 1.95; 95% CI 1.23-3.09; p = 0.004). R1 resection was associated with shorter OS (20 vs. 40 months; p < 0.0001) and disease-free survival (5 vs. 9 months, p = 0.005) than R0 resection. Patients with an R1 resection exhibited a lower histological and biological response to preoperative chemotherapy (p < 0.05).

An R1 resection after intensive induction chemotherapy by FX, undertaken in about one-third of resection cases, is a major prognostic factor associated with reduced long-term survival.