Abstract
BACKGROUND: This study aimed to compare the benefits and identify the best second-line treatment regimen for gemcitabine-refractory unresectable pancreatic cancers. PATIENTS AND METHODS: This retrospective analysis included 144 patients with unresectable pancreatic cancer who underwent a gemcitabine-based regimen as the first-line treatment. 57, 37, and 50 patients received oxaliplatin-, irinotecan-based, and modified FOLFIRINOX (mFFX) regimens, respectively. The primary endpoint of this study was progression-free survival (PFS) and the secondary endpoints were overall survival (OS), response rate, and treatment-related toxicity. RESULTS: There were no significant differences in median PFS (mPFS) (4.6 months vs. 2.9 months, P = 0.627, HR = 1.128, 95%CI 0.693-1.836) and median OS (mOS) (6.5 months vs. 10.2 months, P = 0.108, HR = 0.664, 95%CI 0.392-1.125) between irinotecan- and oxaliplatin-based groups. The mOS was significantly longer in the mFFX group than in the Iri/Oxa group (pooled the irinotecan- and oxaliplatin-based groups) (10.7 months vs. 8.8 months, P = 0.035, HR = 1.560, 95%CI 1.037-2.347), whereas no statistical difference was observed in mPFS between the two groups (4.4 months vs. 4.2 months, P = 0.222, HR = 1.247, 95%CI 0.866-1.797). However, after propensity score matching adjustment, no significant differences were found in mPFS (3.5 months vs. 4.2 months, P = 0.290, HR = 0.763, 95%CI 0.448-1.297) and mOS (8.5 months vs. 12.4 months, P = 0.464, HR = 1.262, 95%CI 0.673-2.367) between mFFX and Iri/Oxa groups. Survival analysis by performance status showed that patients with good performance status lived longer than those with poor performance status (10.8 months vs. 7.7 months, P = 0.000, HR = 2.194, 95%CI 1.408-3.420), suggesting that patient performance status, rather than the treatment regimen, was the primary factor affecting overall survival during second-line treatment. CONCLUSIONS: In the second-line treatment of pancreatic cancer, the efficacy of common treatment regimens is not significantly different, while a good performance status is the key factor influencing survival. Thus, it is recommended that supportive care be enhanced concurrently with systemic therapy in patients with pancreatic cancer.