Does the Addition of Radiation to Neoadjuvant Systemic Therapy Improve Outcomes for Patients with Resected Pancreatic Adenocarcinoma? Analysis of the National Cancer Database

Abstract

Abstract Purpose The incorporation of neoadjuvant radiation therapy into the treatment algorithm for pancreatic cancer is a topic of ongoing debate. This study compares neoadjuvant chemotherapy (NAC) alone to NAC combined with radiation (NAC + RT). Methods Using the national cancer database, we identified patients diagnosed with pancreatic adenocarcinoma from 2018–2019. We assessed the pathological response using the “post therapy path” variable, with complete pathologic response (pCR) indicating no residual disease in the resected specimen. Results Among the 4,079 patients in the study, pCR was achieved in 4.1%. Treatment with NAC + RT was associated with an increased rate of pCR (6.1%) compared with the NAC alone (3.2%) (P < 0.001). An interval > 11 weeks between surgery and radiation correlated with a higher pCR rate (≤ 11 weeks: 4.8% vs. >11 weeks: 7.8%; P = 0.038). Additionally, NAC + RT was associated with more AJCC downstaging (n = 627, 57.1%) compared to the NAC group (n = 1,147, 40.8%) (P < 0.001). Pathologic complete response was associated with improved OS regardless of neoadjuvant treatment modality. Conclusion This study gives a real world snap-shot of utilization of neoadjuvant therapy for PDAC in the United States. NAC + RT is associated with improved pCR, AJCC downstaging, and margin-negative resections. Further study is needed to define the role of NAC + RT in the management of PDAC.