A phase II study of stereotactic radiotherapy after FOLFIRINOX for locally advanced pancreatic cancer (LAPC-1 trial): Long-term outcome.

Purpose: To report the long-term outcome of a multicenter phase II study with FOLFIRINOX followed by stereotactic body radiotherapy (LAPC-1 trial) in patients with locally advanced pancreatic cancer (LAPC). Materials and

Methods: Patients with histological confirmation of LAPC inoperable at diagnosis were enrolled. Induction therapy with 8 cycles of FOLFIRINOX was administered. If no disease progression was found after chemotherapy, patients received stereotactic body radiotherapy (SBRT) at a total dose of 40 Gy in 5 fractions.

Results: In LAPC-1 trial, 50 patients were included, but due to disease progression in 11 patients under chemotherapy, 39 patients received stereotactic SBRT after FOLFIRINOX treatment. In whole population, the 1- and 3-year overall survival (OS) were 62% and 10%, respectively. Median follow-up was 13 months. The SBRT group had median OS of 18 months (95% CI 13.2-21.5) versus 5 months (95% CI 4.1-6.7) in non-SBRT group (p<0.001). After chemoradiotherapy, seven patients underwent surgery achieving a radical resection. Patients who underwent surgery had a 3-years OS of 43% compared to 6.5% in the unresected group (p=0.03). Four patients developed grade ≥ 3 adverse events during SBRT.

Conclusions: Long-term survival has been found in patients with LAPC underwent FOLFIRINOX followed by SBRT. This approach increased the probability of a radical surgery. The resected patients achieved a significant better survival compared to unresected group.