Effect of irreversible electroporation (IRE) combined with chemotherapy (C) on survival in locally advanced pancreatic cancer (LAPC) patients (pts).

Abstract

e15723 Background: LAPC represents 40% of PC pts. IRE is a non-thermal ablative technique that can be used in inoperable pts and safely combined with C. Methods: From 2015 to 2018 laparotomic IRE was performed in a total of 34 LAPC pts. The median age was 64.7yrs (range, 46-81yrs) and 15 (44%) were males. The median tumor size was 3.9cm (range, 2-5.2cm) with the majority of tumors located at pancreatic head (26 pts, 76%), followed by body (6 pts, 18%) and tail of pancreas (2 pts, 6%). Induction C was applied in 27 out of 34 pts and in case of disease control IRE was done, while in 7 pts IRE was done without prior C. In the majority of pts C after IRE was also given. Results: Induction C was applied in 27 out to 34 pts (80%) [FOLFIRINOX in 16 pts, nab-paclitaxel-gemcitabine (AG) in 11 pts]. After the completion of 3 cycles of C tumor evaluation showed partial response (PR) in 20 pts and stable disease (SD) in 7 pts. All pts were treated with IRE and 50% of them had a preoperative biliary stent, while 3 pts had metallic stent that was removed before IRE. No IRE-related deaths occurred. Two major complications grade III were reported: pancreatic fistula grade A in 7 pts and 2 pts diagnosed with delayed gastric emptying. There was also one minor complication (wound infection) in 3 pts (9%). Up to 31/12/2018, the median overall survival (OS) of all pts was 24.2 months (mos) (range, 6-36 mos) and median progression free survival (PFS) was 14.6 mos (range, 3-24 mos). The median OS of the pts treated with C-IRE-C was 22.5 mos (range, 13-36 mos) and median PFS 16.9 mos (range, 3-24 mos), while in pts treated with IRE-C only was 15 mos (6-22 mos) and 10.9 mos (range, 5-16 mos), respectively. The group treated with FOLFIRINOX-IRE-C showed median OS 22.5 mos (range, 15-36 mos) and median PFS 17.1 mos (range, 3-24 mos), while the group treated with AG-IRE-C had median OS 19 mos (range, 13-36 mos) and median PFS 15.8 mos (range, 7-24 mos). After IRE, 24 pts (71%) continued with adjuvant C, either FOLFIRINOX 5 pts (15%) or G-based regimen 18 pts (46%) until disease progression or unacceptable toxicity, while 12 pts (35%) have more than 24 mos OS and 3 pts (9%) have reached 36 mos OS and are still alive. Conclusions: The combination of C with IRE is safe and results in survival increase of LAPC pts. Pts treated with the sequence FOLFIRINOX-IRE-C seems to benefit the most.