Objective: The aim of this study was to characterize the patterns and treatment of disease recurrence in patients achieving a pathological complete response (pCR) following neoadjuvant chemoradiation for advanced pancreatic ductal adenocarcinoma (PDAC).
Summary of background data: A pCR is an independent predictor for improved survival in PDAC. However, disease recurrence is still observed in these patients.
Methods: Patients with advanced PDAC who were treated with neoadjuvant therapy and had a pCR were identified between 2009 and 2017. Overall survival (OS) was determined from the initiation of neoadjuvant, disease-free survival (DFS) from the date of surgery, and post-recurrence survival (PRS) from the date of recurrence. Factors associated with recurrence were analyzed using a Cox-regression model.
Results: Of 331 patients with borderline resectable or locally advanced PDAC, 30 achieved a pCR following neoadjuvant treatment and pancreatectomy. The median DFS for pCR patients was 29 months and OS 76 months. Recurrence was observed in 14 patients. No clinicopathologic or treatment characteristics were associated with survival. The median PRS following recurrence was 25 months. Treatment following recurrence included chemotherapy, radiation or ablation, and surgical resection. Hepatectomy or completion pancreatectomy was accomplished in 2 patients that remain alive 13 and 62 months, respectively, following metastasectomy.
Conclusions: A pCR following neoadjuvant therapy in patients with advanced PDAC is associated with remarkable survival, although recurrence occurs in about half of patients. Nevertheless, patients with pCR and recurrence respond well to treatment and survival remains encouraging. Advanced molecular characterization and longitudinal liquid biopsy may offer additional assistance with understanding tumor biologic behavior after achieving a pCR.