Relapse-free survival (RFS) after surgical resection to predict survival after relapse (SAR) and overall survival (OS) in patients with pancreatic ductal adenocarcinoma (PDA).

Abstract

e15735 Background: We aimed to evaluate the clinical relevance of RFS after local PDA resection as a prognostic factor in terms of SAR and OS. Methods: Patients diagnosed with local PDA who had undergone surgical resection in 4 hospitals from Spain were identified. Disease location, demographic, pathologic, treatment during recurrence and mortality information was retrospectively collected. RFS was measured from date of surgery until recurrence and censored at death or last follow-up. SAR was measured from relapse, until death or last follow-up. We defined patients presenting an RFS value of 6 months or more, or less than 6 months as High-RFS and Low-RFS respectively. Results: Of 93 patients with resected PDA, 51 (54.8%) were male and 42 (45.2%) female. The median age was 65.2 years. 62 (66.7%) tumors were localized in the head. There were 5 (5.4%), 17 (18.3%) and 69 (74.1%) stage I, II and III respectively. 53 (57%) patients had undergone cephalic (Whipple), 20 (21.5%) distal and 20 (21,5%) total pancreatectomy. 48 (51.6%) patients received radiotherapy and 86 (92.5%) received chemotherapy in the neoadjuvant and/or adjuvant setting. Median RFS was 12.3 months. In the metastatic setting, the most frequent chemotherapy combination was gemcitabine plus nab-paclitaxel. 43(46,2%) of patients received second line chemotherapy. Median OS and median SAR were 25,9 and 10,1 months respectively. Kaplan-Meier survival analysis showed that PDA cancer patients with Low-RFS have a poorer clinical outcome than those with High-RFS (median OS 48.26 months, CI 95% 39,3-57,1 for High-RFS; 19.2 months CI 95% 15.7-22-8 for Low-RFS; p = 0.0001). On multivariate Cox regression analysis, age, initial stage I-II, adjuvant chemotherapy utilization and High-RFS were independent prognostic factors for OS and SAR rate. Conclusions: RFS was strongly correlated and discriminated PDA patients with better SAR and OS from the poorer prognosis patients in the ulterior metastatic setting. Prospective studies are needed to confirm this finding.