Efficacy of immune checkpoint inhibitors combined with different chemotherapy in recurrent pancreatic cancer: a retrospective study

Objective Recurrence affects 65%-75% of pancreatic cancer (PC) patient post-resection. Established salvage strategies for recurrent PC are lacking, and systemic chemotherapy offers limited survival benefits. This study aimed to evaluate the efficacy and safety of immune checkpoint inhibitors (ICIs) combined with different chemotherapy in patients with recurrent PC, specifically FOLFIRINOX (a combination of 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin) and Gemcitabine plus Nab-paclitaxel (AG). Materials and methods: We retrospectively screened 201 patients with recurrent PC between March 2016 and September 2022. A total of 113 eligible patients were enrolled, including 23 in the chemotherapy combined with ICIs group and 90 in the chemotherapy-only group. The primary endpoint was overall survival (OS), and secondary endpoints included progression-free survival (PFS). Subgroup analyses were performed based on chemotherapy regimens (FOLFIRINOX vs. AG). Results In the overall cohort, the chemotherapy combined with ICIs group demonstrated a trend toward improved survival compared to the chemotherapy group. Subgroup analysis revealed that among patients receiving the FOLFIRINOX regimen, the addition of ICIs was significantly associated with improved OS (median OS: not reached vs. 14.9 months; HR = 0.266 [95% CI: 0.077-0.919]; log-rank P = 0.025; Cox P = 0.036) and showed a superior trend in PFS ( P = 0.080) compared to FOLFIRINOX alone. Conversely, no significant survival benefit was observed in the AG subgroup ( P > 0.05). Conclusion Combining ICIs with FOLFIRINOX-based chemotherapy was significantly associated with improved OS in patients with recurrent PC with an acceptable safety profile. This combination strategy represents a promising therapeutic option for recurrent PC, particularly when paired with the FOLFIRINOX backbone.