Is neoadjuvant chemoradiation important in borderline resectable pancreatic cancer (BRPC)? Clinical and surgical outcomes associated with preoperative FOLFIRINOX alone in BRPC.

Abstract

351 Background: Neoadjuvant therapy is recommended to increase the likelihood of margin-negative (R0) resection for BRPC. However, there is no consensus regarding the optimal treatment paradigm, including the respective roles of chemotherapy and radiation (RT), in this setting. Methods: Retrospective analysis was conducted of BRPC pts treated with neoadjuvant FOLFIRINOX followed by surgical resection at a single tertiary care referral center over a 4-year period. Data collected included baseline pt characteristics, toxicity profiles, radiographic and serum CA19-9 response, perioperative complication rate, R0 resection rate, histopathologic response, and frequency and patterns of recurrence. Results: 26 BRPC pts received neoadjuvant FOLFIRINOX, 22 w/o addn RT. Abutment of the SMV (n = 9, 40.9%), SMA (n = 4, 18.2%), CHA (n = 4, 18.2%), and narrowing of the SMV (n = 4, 18.2%) were the most common vascular involvement. 9 (40.9%) pts had both arterial and venous involvement. Median baseline CA19-9 level was 278.5 U/ml. Pts received a median of 9 treatment cycles (range, 4-12). Radiographic response was categorized as shrinkage (n = 11, 50%), stable (n = 9, 40.9%), or progression (n = 2, 9.1%). The Whipple procedure was the most common operation performed (n = 17, 77.3%), with 12 pts (54.5%) requiring vascular reconstruction. Clavien-Dindo complication rates of grade 0, I, II, and IIIa occurred in 25.9%, 11.1%, 44.4%, and 14.8% of pts, respectively. R0 resection rate was 90.9%, with 13 (59.1%) having negative lymph nodes. Treatment response of Evans grade III or IV, corresponding to < 10% residual tumor cells, was seen in 8 pts (36.4%), including one pathologic CR (4.5%). AJCC Stage: ypT3N0 (36.4%), ypT3N1 (18.2%), ypT1N1 (18.2%). With a median f/u time of 22.1 months, 8 pts (36.4%) have progressed, inc 7 (87.5%) with distant disease. Median PFS is 22.5 mos. Conclusions: This is one of the largest series to report on the use of neoadjuvant chemotherapy w/o RT in BRPC pts. FOLFIRINOX alone in this setting is associated with high R0 resection rates and favorable clinical outcomes, and should be further assessed in prospective study design for BRPC.