Adjuvant chemoradiation for node-positive pancreatic adenocarcinoma: A propensity-matched analysis

• Published in: Journal of clinical oncology Vol. 35; no. 4_suppl; p. 347
• Main Authors: Raoof, Mustafa, Melstrom, Laleh Golkar, Warner, Susanne, Woo, Yanghee, Singh, Gagandeep, Chen, Yi-Jen, Fong, Yuman
• Format: Journal Article
• Language: English
• Published: 01.02.2017
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/JCO.2017.35.4_suppl.347

Abstract only 347 Background: American Society of Clinical Oncology guidelines recommend adjuvant chemoradiation (ACR) for margin-positive(R1) and/or node-positive (N+) pancreatic cancers. However, randomized trials and meta-analyses have have not shown superiority of ACR over AC. Methods: National Cancer Database (NCDB) was used to analyze patients with N+ and/or R1 pancreatic adenocarcinoma who underwent ACR or AC over a ten-year period (2004-2014). Patients who received neoadjuvant radiation, no adjuvant treatment or adjuvant radiation alone were excluded. Propensity score nearest-neighbor 1:1 matching (PSM) was performed between ACR and AC groups based on age, sex, race, insurance, comorbidities, T-stage, nodal status, margin status, grade, and neoadjuvant chemotherapy. Primary outcome was overall survival (OS). Results: A total of 9,732 patients were eligible. After PSM two well-balanced groups of 4000 patients each were analyzed. ACR resulted in superior OS in patients with N+ and/or R1 disease as compared to AC alone (HR: 0.83, 95% CI 0.78-0.87; Median OS 22 vs. 19 months, p<0.001). Subset analyses demonstrated overall survival benefit of ACR compared to AC in N+, margin-negative patients (HR: 0.82, 95% CI 0.77-0.88; Median OS 24 vs. 20 months, p<0.001), as well as N+, R1 patients (HR: 0.77, 95% CI 0.68-0.87; Median OS 17 vs. 15 months, p<0.001); but no benefit in node-negative, R1 patients (HR: 1.12, 95% CI 0.84-1.48; Median OS 18 vs. 22 months, p = 0.43). Conclusions: This is the largest study to date that shows superiority of ACR over AC in N+ patients irrespective of margin status. The study failed to show a survival benefit in R1, node-negative patients.