Validation of the PANAMA-Score for Survival and Benefit of Adjuvant Therapy in Patients with Resected Pancreatic Cancer After Neoadjuvant FOLFIRINOX

Aim: To validate the prognostic value of the PAncreatic NeoAdjuvant MAssachusetts (PANAMA)-score and to determine its predictive ability for survival benefit derived from adjuvant treatment in patients after resection of pancreatic ductal adenocarcinoma (PDAC) following neoadjuvant FOLFIRINOX Background: The PANAMA-score was developed to guide prognostication in patients after neoadjuvant therapy and resection for PDAC. As this score focuses on the risk for residual disease after resection, it might also be able to select patients who benefit from adjuvant after neoadjuvant therapy. Methods: This retrospective international multicenter study is endorsed by the European-African Hepato-Pancreato-Biliary Association (E-AHPBA). Patients with PDAC who underwent resection after neoadjuvant FOLFIRINOX were included. Mantel-Cox regression with interaction analysis was performed to assess the impact of adjuvant chemotherapy. Results: Overall, 383 patients after resection of PDAC following neoadjuvant FOLFIRINOX were included of whom 187 (49%), 137 (36%), and 59 (15%) had a low-risk, intermediate-risk, and high-risk PANAMA-score, respectively. A discrimination in median OS was observed stratified by risk groups (48.5, 27.6, and 22.3 months, Log-Rank-Plow-intermediate=0.004, Log-Rank-Pintermediate-high=0.027). Adjuvant therapy was not associated with an OS difference in the low-risk group (HR 1.50, 95%CI:0.92-2.50), whereas improved OS was observed in the intermediate (HR 0.58, 95%CI:0.34-0.97) and high-risk groups (HR 0.47, 95%CI:0.24-0.94) (p-interaction=0.008). Conclusions: The PANAMA 3-tier risk groups (low-risk, intermediate-risk, and high-risk, available via pancreascalculator.com) correspond with differential survival in patients with resected PDAC following neoadjuvant FOLFIRINOX. The risk groups also differentiate between survival benefit associated with adjuvant treatment, with only the intermediate- and high-risk groups associated with improved OS.