Prognosis Associated with Complete Pathological Response Following Neoadjuvant Treatment for PancreaTic AdenOcarciNOma in the FOFLIRINOX Era: the Multicenter TONO Study.

Background: The use of multiagent FOLFIRINOX chemotherapy for pancreatic adenocarcinoma in a neoadjuvant setting has been associated with an increased rate of complete pathological response (CPR) after surgery. This study investigated the long-term outcomes of patients with CPR in a multicenter setting to identify prognostic factors for overall survival (OS) and recurrence-free survival (RFS).

Methods: This retrospective cohort study examined biopsy-proven pancreatic adenocarcinomas with CPR after neoadjuvant chemotherapy or chemoradiotherapy and surgery, between January 2006 and December 2023 across 22 French and  2 Belgian centers. Cox analyses were used to identify prognostic factors of OS and RFS.

Results: There were 101 patients with CPR after chemotherapy (n = 58, 57.4%) and chemoradiotherapy (n = 43, 42.6%) followed by surgery. Neoadjuvant FOLFIRINOX was used in 90% of patients. The median OS after surgery was 177 months (95% confidence interval (CI) 58.9-177 months) with 1-, 3-, 5-, and 10-year OS rates of 93%, 75%, 63%, and 51%, respectively. The median RFS was 67.8 months (95% CI:34.4-NR) with 1-, 3-, 5-, and 10-year RFS rates of 83%, 58%, 54%, and 49%, respectively. The multivariate Cox analysis of OS and RFS showed that preoperative radiotherapy was an independent negative prognostic factor for OS (hazard ratio (HR) 2.51; 95% CI 1.00-6.30; p = 0.03) and RFS (HR 2.62; 95% CI 1.27-5.41; p = 0.009).

Conclusions: Complete pathologic response after neoadjuvant treatment is associated with remarkable long-term survival that is usually not seen after the resection of pancreatic adenocarcinomas. One-third of the patients still experienced disease recurrence, which was more common in those receiving preoperative chemoradiotherapy.