A Single-Center Retrospective Study to Compare the Efficacy and Safety of Modified FOLFIRINOX with S-1 as Adjuvant Chemotherapy in 71 Patients with Resected Pancreatic Carcinoma

Background: Studies are ongoing to determine the optimal adjuvant chemotherapy (ACT) for resected pancreatic carcinoma (PC). FOLFIRINOX is a chemotherapy regimen including oxaliplatin, irinotecan, leucovorin, and 5-fluorouracil (5-FU). S-1 is a fluoropyrimidine derivative widely used as ACT for gastrointestinal malignancy. This singlecenter retrospective study aimed to compare the efficacy and safety of modified FOLFIRINOX (mFOLFIRINOX) with S-1 as ACT for resected PC. Material/Methods: A total of 71 patients with PC who accepted ACT after R0 resection between February 2016 and January 2019 were enrolled in this retrospective study. Among these patients, 34 received mFOLFIRINOX regimen chemotherapy (mFFX group), while 37 received S-1 monochemotherapy (S-1 group). The mFOLFIRINOX regimen included oxaliplatin 65 mg/m2, leucovorin 400 mg/m2, irinotecan 150 mg/m2, 5-FU 400 mg/m2, and continuous 5-FU 2400 mg/m2 (for 46 h), in a 2-week schedule. The S-1 monochemotherapy (80-120 mg/day according to body surface area [BSA], in 2 divided doses for 2 week) was administrated every 3 weeks. We followed up these patients and analyzed the relapse-free survival (RFS), overall survival (OS), and chemotherapy-induced adverse events (AEs). Results: The mFFX group demonstrated a markedly higher 3-year RFS (P=0.0332) and OS (P=0.0346) than the S-1 group. Patients in the mFFX group experienced significantly more common and severe thrombocytopenia (P=0.0372), fatigue (P=0.0226), nausea/vomiting (P=0.0337), and diarrhea (P=0.0018). No chemotherapy-induced death was documented. Conclusions: This retrospective study indicated that if dose adjustment and adverse events management are properly administrated, mFOLFIRINOX regimen chemotherapy could result in an improved survival compared with S-1 monochemotherapy for resected PC.