A retrospective review of borderline resectable-locally advanced pancreatic adenocarcinoma (BR-LAPC) undergoing neoadjuvant chemotherapy followed by stereotactic body radiation therapy (SBRT) at the University of Colorado Cancer Center.

Abstract

436 Background: Metastatic pancreatic chemotherapy regimens are often used as neoadjuvant treatment in the LAPC setting. The University of Colorado has a treatment paradigm for BR-LAPC which consists of 2-4 months of chemotherapy followed by SBRT then reevaluated for surgical resection. Methods: Retrospective analysis of patients with pathologically confirmed BR-LAPC who received all neoadjuvant treatment (chemotherapy and SBRT) with intention of undergoing surgical resection at the University of Colorado Cancer Center from 2012 to 2017. Baseline data collected includes demographics, comorbidities, disease characteristics and chemotherapy regimen FOLFIRINOX or Gemcitabine/Nab-Paclitaxel (GNP). The objective of the study is to describe the correlation of neoadjuvant regimens and clinical outcomes. Results: A total of 100 patients were identified with 40 patients collected for the interim analysis. Of these patients 82.5% (N = 33) received FOLFIRINOX and 17.5% (N = 7) received GNP. Patients who received FOLFIRINOX, 78.8% went for surgical resection compared to 85.7% in the GNP group. The number of patients who had a reported College of American Pathology (CAP) grade ≤1, representing no or minimal residual disease, was 3 for the FOLFIRINOX group and no patients in the GNP group. The percent of patients in the FOLFIRINOX group who achieved R0 resections was 90% compared to 83% for the GNP group. Mean initial CA 19-9 was 38.5U/ml, 386.7U/ml, and 1799.8U/ml in CAP grade 1, 2, 3 respectively, while percent reduction in CA 19-9 level during neoadjuvant was 33.3%, 69.7%, and 72.4% respectively. Assessment of the impact of relative dose intensity for each neoadjuvant regimen on clinical outcomes is ongoing. Conclusions: FOLFIRINOX neoadjuvant treatment was associated with improved surgical outcomes including an increased rate of R0 and CAP grade ≤1 resections. Low initial CA 19-9 levels were associated with favorable surgical and pathologic outcomes whereas absolute or relative CA 19-9 reductions with neoadjuvant were not. Final analysis of all 100 patients will be reported.