Recurrence after neoadjuvant therapy and resection of borderline resectable and locally advanced pancreatic cancer

Introduction: The incidence, timing, and implications of recurrence in patients who underwent neoadjuvant treatment and surgical resection of borderline resectable (BRPC) or locally advanced (LAPC) pancreatic cancer are not well established. Materials and methods: Patients with BRPC/LAPC who underwent post-neoadjuvant resection between 2007 and 2015 were included. Associations between clinicopathologic characteristics and specific recurrence locations, recurrence-free survival (RFS), and overall survival from resection (OS) were assessed using Cox regression analyses. Results: For 231 included patients, median survival from diagnosis and resection were 28.0 and 19.8 months, respectively. After a median RFS of 7.9 months, 189 (81.8%) patients had recurred. Multiple-site (n = 87, 46.0%) and liver-only recurrence (n = 28, 14.8%) generally occurred earlier and resulted in significantly worse OS when compared to local-only (n = 52, 27.5%) or lung-only recurrence (n = 18, 9.5%). Microscopic perineural invasion, yN1-yN2 status and elevated pre-surgery CA 19-9 >100 U/mL were associated with both local-only and multiple-site/liver-only recurrence. R1-margin was associated with local-only recurrence (HR 2.03). yN1-yN2 status and microscopic perineural invasion were independent predictors for both poor RFS and OS, while yT3-yT4 tumor stage (HR 1.39) and poor tumor differentiation (HR 1.60) were only predictive of poor OS. Adjuvant therapy was independently associated with both prolonged RFS (HR 0.73; median 7.0 vs. 10.9 months) and OS (HR 0.69; median 15.4 vs. 22.7 months). Conclusion: Despite neoadjuvant therapy leading to resection and relatively favorable pathologic tumor characteristics in BRPC/LAPC patients, more than 80% of patients experienced disease recurrence, 72.5% of which occurred at distant sites.