Impact of resection margins and para-aortic lymph node metastases on recurrence patterns and prognosis in resectable pancreatic cancer - a long-term population-based cohort study.

ABSTRACT

BACKGROUND: Pancreatic cancer remains a leading cause of cancer-related death. To individualise management and improve survival, more accurate prognostic models are needed. METHODS: All patients resected for pancreatic ductal adenocarcinoma in a tertiary Swedish centre during 2009-2019 were thoroughly analysed with regards to pathological and clinical parameters including tumour grade, resection margin status, para-aortic lymph node engagement (node station 16), and systemic treatment. RESULTS: The study cohort included 275 patients. Overall median survival was 21.2 months (95% CI 17.5-24.8). Year of resection, margin status (R1 subdivided into R11mm/R1ink), perineural invasion, differentiation grade, TNM stage, and adjuvant therapy were independent factors with significant impact on survival. Margin status also significantly affected recurrence-free survival and relapse patterns, with local and peritoneal relapses being associated with R1-status (p < 0.001 and p = 0.007). Presence of para-aortic lymph node metastases was associated with shorter recurrence-free survival as compared to N1 status only. CONCLUSION: Survival in resected pancreatic cancer is improving over time. Resection margin status is a key factor affecting recurrence patterns and prognosis. Given the poor recurrence-free survival in node station 16 metastasised patients, the rational for resection remains in doubt, and improved treatment strategies for this patient group is necessary.