Tolerability, Attrition Rates, and Survival Outcomes of Neoadjuvant FOLFIRINOX for Nonmetastatic Pancreatic Adenocarcinoma: Intent-to-Treat Analysis.

Abstract

FOLFIRINOX is increasingly used in the management of pancreatic ductal adenocarcinoma (PDAC). However, neoadjuvant therapy is associated with toxicity, possible disease progression, and biopsy-related and biliary complications that may preclude operative exploration. Data on the true attrition rate outside of clinical trials or resected surgical series are lacking. Patients with nonmetastatic PDAC who initiated FOLFIRINOX from 2015 to 2020 were identified from our institution's pharmacy records. Multivariable regression and Cox proportional hazard models were used for adjusted analyses of categorical and survival outcomes, respectively. Of 254 patients who initiated first-line neoadjuvant FOLFIRINOX, 199 (78.3%) underwent exploration, and 54 (21.3%) did not complete their chemotherapy cycles due to poor tolerability (46.3%), poor response (31.5%), or disease progression (14.8%), among other causes (7.4%). A total of 109 (42.9%) patients experienced grade 3/4 FOLFIRINOX-related toxicity, of whom 73 (28.7%) and 100 (39.4%) required an emergency department visit or inpatient admission, respectively. Finally, not undergoing surgical exploration was associated with impaired overall survival (hazard ratio 7.0; 95% CI 3.8 to 12.8; p < 0.001). Independent predictors of not undergoing exploration were remote history of chemotherapy receipt (odds ratio [OR] 0.06; p = 0.02), inability to complete FOLFIRINOX cycles (OR 0.2, p = 0.003), increase in ECOG score (OR 0.2, p < 0.001), and being single or divorced (OR 0.3, p = 0.018). Among 254 patients with nonmetastatic PDAC initiated on FOLFIRINOX, of whom 52% were locally advanced, a total of 199 (78.3%) were explored, 142 (71.4%) underwent successful resection, and 129 (90.8%) were resected with negative margins. Despite 109 (42.9)% of patients experiencing significant toxicity, most patients could be managed through treatment-related complications to complete planned neoadjuvant chemotherapy and undergo planned surgical exploration.