Survival impact of adjuvant chemotherapy in PDAC patients with persistent LVI and lymph node involvement after neoadjuvant chemotherapy

Neoadjuvant treatment (NAT) is increasingly used for patients with pancreatic ductal adenocarcinoma (PDAC). The role of additional adjuvant therapy (AT) is not well-defined. An observational cohort study at Mayo Clinic Arizona (Phoenix) investigated the impact of lymphovascular invasion (LVI) and lymph node (LN) involvement on overall survival (OS) in patients with resected PDAC after NAT and the impact of AT. Seven thousand four hundred and fourteen patients were included; group A (LVI- LN-) had 2787 patients; group B (LVI+, LN-) 652; group C (LVI-, LN+) 1712; and group D (LVI+ LN+) 2263. Median OS differed significantly between groups: median OS was 34.1 months in A, 27.8 months in B, 26.3 months in C, and 21.1 months in D (p<0.001). In patients with persistent LVI or LN involvement after NAT, additional AT was not associated with OS. The authors conclude that LVI and LN involvement after NAT were independently associated with worse OS; use of AT in these patients was not associated with improved OS.