Short- and Long-Term Outcomes of Neoadjuvant Stereotactic Body Radiation Therapy vs Neoadjuvant Conventional Radiation Therapy in Patients with Pancreatic Cancer

Abstract

INTRODUCTION: Although neoadjuvant chemotherapy is widely accepted in treatment of pancreatic cancer, there is no consensus on the modality of neoadjuvant radiotherapy (NRT) with neoadjuvant Stereotactic Body Radiation Therapy (SBRT) gaining more interest. Our goal was to compare SBRT vs conventional radiation therapy (CRT). METHODS: A retrospective analysis of National Cancer Database data from 2004 to 2018 was conducted. Patients who underwent NRT followed by surgical resection with known radiation and survival data were included. The primary outcome was overall survival (OS) and secondary outcomes include 30- and 90-day postoperative mortality, pathologic complete response (pCR), and R0 resection. RESULTS: The SBRT group (average 33 Gy/5 fx) comprised 392 patients, and 467 patients received CRT (average 45 Gy/25 fx). Median OS for patients undergoing CRT compared with the SBRT group was 22 vs 34 months (p < 0.001). The SBRT group had better median OS among AJCC clinical stage 1, 2 and 3 compared with CRT (32 vs 26 months, p = 0.078; 34 vs 21 months, p < 0.001; and 37 vs 23 months, p < 0.001, respectively). The 30- and 90-day postoperative mortality for CRT compared with SBRT group was 5% vs 2% (p = 0.02) and 12% vs 6% (p = 0.002), respectively. R0 resection and pCR rate for CRT compared with SBRT was 85% vs 87% (p = 0.96) and 3.7% vs 3.8% (p = 0.77), respectively (Figure).FigureCONCLUSION: Patients who underwent neoadjuvant SBRT compared with CRT had superior OS, particularly in AJCC stage 2 and 3, along with decreased postoperative mortality. Further randomized controlled trials are warranted.