The Relationship between Treatment Response and Overall Survival in Borderline, Non-Resectable and Resectable Pancreatic Cancer Patients Treated with Neoadjuvant FOLFIRINOX

<b>Background</b>: The National Comprehensive Cancer Network (NCCN)-recommended treatment for patients with borderline-resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) involves a combination of neoadjuvant FOLFIRINOX chemotherapy and the curative surgical resection of the tumor. This study seeks to identify the clinical, radiological, laboratory, and pathologic predictors that can anticipate the oncological outcomes of patients. <b>Methods</b>: In this study, we conducted a retrospective analysis of patients who had undergone curative surgical resection for BRPC, LAPC, or resectable disease with high-risk features after receiving neoadjuvant FOLFIRINOX at two institutions. We evaluated by means of multivariate analysis whether clinical and laboratory response, tumor markers, radiological response, and pathologic tumor response grade correlated with overall survival (OS) and disease-free survival (DFS). <b>Results</b>: The study enrolled a total of 70 patients with BRPC, LAPC, and resectable disease with high-risk features who underwent resection after neoadjuvant FOLFIRINOX. Age above 65 years and fewer than nine cycles of chemotherapy (OR 4.2; 95% CI 1.4-12.0; <i>p</i>-value 0.007); locally advanced tumors after neoadjuvant treatment (NAT) (OR 7.0; 95% CI 1.9-25.7; <i>p</i>-value 0.003); and lymph node disease and histological tumor regression grade 2 and 3 (OR 4.3; 95% CI 0.9-19.2; <i>p</i>-value 0.05) were risk factors linked to adverse OS and DFS. The median OS and DFS were 33 (22-43.9) months and 16.5 (11.3-21.6) months, respectively. <b>Conclusions</b>: Classification as a LA tumor after NAT was the only preoperative radiological factor that predicted adverse survival in patients undergoing curative surgery after NAT. Other clinical, biochemical, and radiological measures of response were not found to predict OS. Patient age, the cumulative administration of more than eight cycles of chemotherapy, and a significant pathological response were associated with better OS. The results of this study are important for treatment decision-making and prognostication in patients with BRPC and LAPC.