Outcomes for patients with borderline resectable (BR) and locally advanced (LA) pancreatic cancer (PC) treated with induction FOLFIRINOX (FFX) +/- radiation (RT) followed by surgery compared to induction FFX followed by consolidative RT.

Abstract

437 Background: Induction FFX for PC deemed either BR or LA at diagnosis provides an opportunity to downstage pts with the aim of an R0 surgery. The addition of RT after induction FFX may further downstage. However, there is a paucity of data regarding long-term survival for BR and LA patients successfully downstaged and resected. We performed a retrospective review of BR and LA PC treated with induction FFX +/- RT followed by surgery or consolidative RT at the Yale Cancer Center (YCC) to assess survival in these two cohorts. Methods: Clinical data was abstracted for pts with BR or LA PC who had surgery or received consolidative RT without surgery after induction FFX +/- RT at the YCC from 2010-2018. Surgical pts were re-reviewed by a radiologist to assess vascular involvement (BR vs. LA) using NCCN criteria. PFS and OS for surgery and consolidative RT were analyzed by the Kaplan-Meier method. Survival was compared via the log rank test. Results: 102 pts met inclusion criteria (BR=47, LA=55), 41 pts had surgery [BR=29/47 (62%) LA=12/55 (22%)] and 61 pts had consolidative RT [(BR= 18/47 (38%), LA= 43/55 (78%)] after induction FFX. 18 surgery pts received RT prior to resection and all surgery pts had R0 resection. Median follow up was 25 mo (range 5 – 97). Median PFS with surgery was 22 mo (95% CI 15 – 59) vs 14 mo (95% CI 10.9 – 20.1) with consolidative RT (p<0.001), while OS with surgery was 42 mo (95% CI 25-NR) vs 20 mo (95% CI 17-25) without surgery (p<0.001). For pts with ≥ 2 yr follow up, 12/22 (55%) surgery pts and 17/18 (94%) consolidative RT pts relapsed. For pts with ≥ 3 yr follow up, 6/12 (50%) surgery pts and 10/10 (100%) consolidative RT pts relapsed. 2 yr PFS and OS was 45% (95% CI 28-61) and 74% (95% CI 57 – 86) with surgery versus 15% (95% CI 7-27) and 40% (95% CI 26-53) with consolidative RT. Conclusions: Surgery was associated with a high R0 rate and prolonged PFS and OS compared to consolidative RT in pts with BR and LA PC after FFX +/- RT. However, survival benefit was not statistically significant when selecting only LA pts although numbers are limited.