Comparison of neoadjuvant chemotherapy plus radiation vs. chemotherapy alone on complete pathologic response in pancreatic adenocarcinoma: an analysis of the national cancer database

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).

Using the national cancer database, we identified patients diagnosed with non-metastatic pancreatic adenocarcinoma from 2018 to 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.

Among the 4079 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 = 1147, 40.8%) (P < 0.001). Pathologic complete response was associated with improved OS regardless of neoadjuvant treatment modality.

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.