Purpose: To assess the efficacy of FOLFIRINOX(FFX), gemcitabine-based regimens (GB), and gemcitabine monotherapy (Gem) in patients with metastatic pancreatic ductal adenocarcinoma (mPDAC).
Methods: This is a retrospective study that included 83 patients with mPDAC treated with first-line chemotherapy (L1) with either FFX, GB or Gem between 2015 and 2017. Progression-free survival (PFS) for L1 and second-line chemotherapy (L2) (PFS-L1 and PFS-L2) and overall survival (OS) were estimated using the Kaplan-Meier method.
Results: Median PFS-L1 for FFX, GB and Gem groups was 9 months (95% (Confidence Interval) CI 2.76-15.24), 5 months (95%CI 3.44-6.56), and 5 months (95%CI 3.76-6.24), respectively (p = 0.04). OS was 14 months (95%CI 11.16-16.85), 12 months (95%CI: 9.44-11.56), and 7 months (95%CI: 5.7-8.3) for patients treated with FFX, GB, and Gem, respectively (p = 0.0001). ECOG-PS (0/1) (Hazard Ratio (HR) 6.74, p = 0.002), age > 70 years (HR 0.25, p = 0.04), body tumors (HR 2.8, p = 0.048), CA19-9 > 39 U/mL (HR 0.26, p = 0.02), and neutrophil-to-lymphocyte ratio (NLR) > 4.15 (HR 6.76, p = 0.001) were independent prognostic factors for PFS-L1. Male gender (HR 3.02, p = 0.026), ECOG-PS (0/1) (HR 4.21, p = 0.003), L1 with FFX (HR 0.255, p = 0.007), and NLR > 4.15 (HR 2.65, p = 0.04) were independent prognostic factors of OS. PFS-L2 (HR 6.91, p = 0.013) and OS-L2 (HR 6.95, p = 0.037) were significantly higher in patients first treated with FFX.
Conclusions: The OS of patients who receive FFX or GB is comparable. The best PFS-L1 belongs to the FFX group. Male gender, ECOG-PS 0/1, the FFX regimen, and NLR > 4.15 were independent predictors of OS. PFS-L2 and OS-L2 were favorably impacted by L1 with FFX.
Keywords: metastatic pancreatic adenocarcinoma; overall survival; palliative chemotherapy; progression-free survival.