Clinical outcomes of second-line chemotherapy in patients with advanced pancreatic adenocarcinoma: a real-world study

Little progress has been made in recent years using first-line chemotherapy, including gemcitabine combined with nab-paclitaxel, FOLFIRINOX, and NALIRIFOX, for advanced pancreatic adenocarcinoma (APC). In addition, the optimal second-line chemotherapy regimen has not been determined. This study aimed to compare the effectiveness of different types of second-line chemotherapy for APC. Patients with APC who received first-line treatment from January 2008 to January 2021 were considered eligible for this retrospective analysis. The primary and secondary endpoints were overall survival (OS) and progression-free survival (PFS), respectively. Four hundred and thirty-seven and 617 patients were treated with 5-fluorouracil- and gemcitabine-based chemotherapy as first-line treatment, respectively. Demographic and clinical features, except age and liver metastasis, were comparable between the two groups ( < 0.05). The median OS was 8.8 and 7.8 months in patients who received a 5-fluorouracil- and gemcitabine-based combined regimen for first-line therapy, respectively (HR = 1.244, 95% CI = 1.090-1.419; < 0.001). The median OS was 5.6 and 1.9 months in patients who received second-line chemotherapy and supportive care, respectively (HR = 0.766, 95% CI = 0.677-0.867; < 0.001). The median PFS was not significantly differently between gemcitabine or 5-fluorouracil monotherapy and combination therapy. A 5-fluorouracil- or gemcitabine-based combined regimen was shown to be as effective as a single 5-fluorouracil or gemcitabine regimen as second-line therapy for patients with APC.