Neoadjuvant Therapy (NAT) in Pancreatic Adenocarcinoma (PAC): A Single Center Experience

Abstract

Background: Surgical resection of PAC followed by adjuvant therapy is the standard of care for localized resectable tumors. Surgical resection, with clear margins, of borderline resectable (BR) or locally advanced (LA) tumors remains quite challenging. NAT could potentially improve outcomes but there are no clear recommendations in this regards for upfront unresectable PAC. Herein, we report our experience with different NAT modalities used in BR and LA PAC. Methods: Medical records of patients identified in our medical database as BR or LA PAC and treated with NAT at Centre Hospitalier de l’Universite de Montreal (CHUM) were retrospectively reviewed. Recist criteria were used for response assessment. Descriptive statistics and Kaplan-Meier were used for statistical purposes. Results: In total, ninety patients met the inclusion criteria (50 BR, 40 LA tumors). Chemotherapy, mostly FOLFIRINOX, was the only modality used in 51 patients (56.6%). Twenty-three patients (25.3%) received concurrent chemoradiation and sixteen patients (17.7%) received sequential chemotherapy and chemoradiation. Tumor resection was possible in 44 patients, 32 BR patients (R0: 68.7%) and 12 LA patients (R0: 75%). Median Disease free survival (DFS) of patients undergoing resection was 12.3 months. Median progression free survival (mPFS) was 29 vs 10 (HR: 0.2; p<0.001) and mOS was 41.7 vs 15.7 months (HR: 0.3; p<0.001) in resected and non-resected patients, respectively. Treatment with more than one modality showed better clinical outcomes (PFS and OS) and a non-statistically higher R0 resection rate that was 100% in BR tumors. OS in patients with resected cancers was not reached for the multimodality group, 41.7 months for chemotherapy alone group and 22.4 months in patients treated with chemoradiotherapy group (p=0.017). Conclusion: In this retrospective single center analysis, NAT appears to improve and enable resection of newly diagnosed PAC. These results validate previous retrospective studies, but warrant large prospective trials to better define the optimal neoadjuvant approach.