Benefit of Gemcitabine/Nab-Paclitaxel Rescue of Patients with Borderline Resectable or Locally Advanced Pancreatic Adenocarcinoma after Early Failure of FOLFIRINOX

Neoadjuvant therapy (NT) is used for advanced pancreatic ductal adenocarcinoma (PDAC). No clear guidelines exist for switching therapies when patients do not respond to initial NT. We sought to characterize patients who underwent early switch from FOLFIRINOX to gemcitabine/nab-paclitaxel (GA) as NT for PDAC. Methods We identified patients at a single institution switched from FOLFIRINOX to GA within the first 4 months of NT for PDAC during 2012-2017. We compared clinicopathologic data and oncologic outcomes. Results Of 25 patients who met the criteria, 21 showed a serologic or radiographic response to GA; 11 (52%) reached resection. Responders had decreased carbohydrate antigen (CA) 19-9 levels from pretreatment to post-GA (P = 0.036). Resected responders had significantly decreased CA 19-9 comparing preswitch to post-GA (P = 0.048). The only predictor of GA response was prechemotherapy CA 19-9 of less than1000 U/mL (P = 0.021). Predictors of reaching resection were head/uncinate tumor (P = 0.010) and presenting stage lower than locally advanced (P = 0.041). Conclusions When patients do not respond to neoadjuvant FOLFIRINOX, early switch to GA should be considered. Future efforts should be directed toward identifying markers that will allow correct choice of initial therapy rather than attempting to rescue patients who respond poorly to first-line therapy.