Outcomes of FOLFIRINOX versus gemcitabine plus nab-paclitaxel in patients with early recurrent pancreatic cancer after adjuvant S-1 treatment: A propensity score-matched analysis.

BACKGROUND: Oral fluoropyrimidine, S-1 is the standard adjuvant chemotherapy for patients with resected pancreatic cancer (PC) in Japan. Patients experiencing early recurrence are typically treated with 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX) or gemcitabine plus nab-paclitaxel (GnP), which are commonly used in patients with advanced PC. However, no clinical studies have compared these regimens in this particular population.

METHODS: This multicenter retrospective study included PC patients who experienced recurrence within six months of the last S-1 administration, including those who had recurrence during the treatment. Patients were treated with either FOLFIRINOX or GnP between December 2013 and 2018. The primary endpoint was overall survival (OS), with secondary endpoints of progression-free survival (PFS), objective response, and serious adverse events (SAEs). Propensity score-matched (PSM) analysis was performed to reduce potential confounding factors between the two groups.

RESULTS: A total of 284 patients from 32 institutions were enrolled. After PSM, 43 patients from each group were compared. Some patient characteristics remained imbalanced between the matched pairs. The GnP group was associated improved OS compared to FOLFIRINOX group (median, 14.5 vs. 11.1 months; hazard ratio [HR], 0.61; 95 % confidence interval [CI], 0.38-0.97). While PFS tended to be longer in the GnP group (median, 7.1 vs. 5.1 months), this difference did not reach statistical significance (HR, 0.65; 95 % CI, 0.41-1.02). The objective response and observed SAEs in the GnP/FOLFIRINOX groups were 20/19 % and 14/19 % respectively.

CONCLUSIONS: GnP was associated with improved OS compared to FOLFIRINOX for patients with early recurrence after adjuvant S-1.