ePoster
Presentation Description
Institution: Alfred health - Victoria, Australia
Background:
Pancreatic ductal adenocarcinoma (PDAC) remains one of the most aggressive solid malignancies, with outcomes heavily influenced by nodal status. The AJCC 8th edition classifies nodal disease solely by the number of involved nodes (N0–N2), without distinguishing between direct tumour invasion into adjacent nodes and true lymphatic metastasis. Whether this morphological distinction carries prognostic relevance remains unclear.
Methods:
A multicentre retrospective cohort study was conducted using data from the Upper Gastrointestinal Cancer Registry across two tertiary hospitals in Melbourne, Australia. Patients with resected, node-positive PDAC (N1) between 2009 and 2024 were included. Direct nodal invasion was defined as contiguous tumour extension into adjacent nodal tissue, while true nodal metastasis was defined as non-contiguous involvement consistent with lymphovascular spread. Recurrence-free survival (RFS) and overall survival (OS) were analysed using Cox proportional hazards regression adjusted for T stage, perineural and lymphovascular invasion, margin status, tumour size, and adjuvant chemotherapy.
Results:
Seventy-nine patients met inclusion criteria and 15% exhibited direct nodal invasion. Compared with true nodal metastasis, direct invasion was associated with significantly improved RFS (adjusted HR 0.22, 95% CI 0.05–0.95, p = 0.043) and OS (HR: 0.29, 95%CI 0.11-0.79, p = 0.015). This corresponded to a 78% reduction in recurrence risk, independent of other prognostic factors.
Conclusion:
Direct nodal invasion in PDAC is associated with superior recurrence-free and overall survival compared with true nodal metastasis, despite identical AJCC staging. These findings suggest that the mechanism of nodal involvement conveys independent prognostic information and should be considered in future refinements of pancreatic cancer staging systems.
Presenters
Authors
Authors
Dr Chen Lew - , Dr Daniel Croagh - , Dr June Oo -
