Clinical outcomes of second-line therapy following disease progression on first-line modified FOLFIRINOX for borderline resectable and locally advanced pancreatic adenocarcinoma

Modified FOLFIRINOX (mFOLFIRINOX) is one of the standard first-line therapies in borderline resectable pancreatic cancer (BRPC) and locally advanced unresectable pancreatic cancer (LAPC). However, there is no globally accepted second-line therapy following progression on mFOLFIRINOX. Patients with BRPC and LAPC (n = 647) treated with first-line mFOLFIRINOX between January 2017 and December 2020 were included in this retrospective analysis. The details of the treatment outcomes and patterns of subsequent therapy after mFOLFIRINOX were reviewed. With a median follow-up duration of 44.2 months (95% confidence interval [CI], 42.3–47.6), 322 patients exhibited disease progression on mFOLFIRINOX—locoregional progression only in 177 patients (55.0%) and distant metastasis in 145 patients (45.0%). The locoregional progression group demonstrated significantly longer post-progression survival (PPS) than that of the distant metastasis group (10.1 vs. 7.3 months, p = 0.002). In the locoregional progression group, survival outcomes did not differ between second-line chemoradiation/radiotherapy and systemic chemotherapy (progression-free survival with second-line therapy [PFS-2], 3.2 vs. 4.3 months; p = 0.649; PPS, 10.7 vs. 10.2 months; p = 0.791). In patients who received second-line systemic chemotherapy following progression on mFOLFIRINOX (n = 211), gemcitabine plus nab-paclitaxel was associated with better disease control rates (69.2% vs. 42.3%, p = 0.005) and PFS-2 (3.8 vs. 1.7 months, p = 0.035) than gemcitabine monotherapy. The current study showed the real-world practice pattern of subsequent therapy and clinical outcomes following progression on first-line mFOLFIRINOX in BRPC and LAPC. Further investigation is necessary to establish the optimal therapy after failure of mFOLFIRINOX.