4. Bidisha Das, MPH

BACKGROUND: The benefit of neoadjuvant radiation (NeoRT) for pancreatic ductal adenocarcinoma (PDAC) is unclear. The Alliance A021501 phase 2 trial found higher R0 resection rate and overall survival (OS) with neoadjuvant modified-FOLFIRINOX compared to modified-FOLFIRINOX plus radiation. ThePREOPANC-2 phase 3 trial found no difference in resection rates or OS between different regimens in the neoadjuvant setting. The aim of this study was to evaluate the association between NeoRT and margin status and LR among patients with PDAC of the head of the pancreas who underwent curative-intent surgery at a high-volume cancer center.
METHODS: Using our institutional database, we collected retrospective clinicopathologic data for 333 patients who underwent a pancreaticoduodenectomy for PDAC between 2016-2022. Chi-square tests, logistic regression, competing risk hazards regression, Kaplan Meier survival analysis, were used to evaluate the association, and effect of NeoRT on margin status and LR.
RESULTS: In a cohort of 333 PDAC patients , median age was 71 years, where 81 (24.3%) of patients received a combination of NeoRT and chemotherapy. Among patients who did not receive NeoRT (n=252), 131 (39.3%) patients only received neoadjuvant chemotherapy. Median post-surgery follow-up time was 22 months . A greater proportion of patients who received NeoRT underwent a vascular reconstruction (25% (20/81) vs 13% (33/252), p<.0001). NeoRT was not associated with margin status (OR 0.1.00, 95% CI 0.56-1.81, p=0.99), LR (p=0.58) or 5-year LR free survival (p=0.17).Stratified analysis based on receipt of NeoRT and +/- vascular involvement showed no statistically significant difference in LR free survival (p=0.40). CONCLUSION: In this cohort of patients with PDAC in the head of the pancreas from a high-volume cancer center, patients at high-risk for LR and who received NeoRT had similar margin status, LR, and LR free survival as patients who were not at high-risk for LR and did not receive NeoRT.