Implications of prolonged time to pancreaticoduodenectomy after neoadjuvant chemoradiation: Analysis of the National Cancer Database.

473Background: For patients with pancreatic adenocarcinoma (PA), the optimal time interval between neoadjuvant chemoradiation (CR) to surgical resection has not been well established. The National Cancer Database (NCDB) was used to evaluate the impact of radiation-surgery (RS) interval on outcomes. Methods: The NCDB from 2006-2014 was queried for patients ≥18 years old diagnosed with PA who received CR prior to surgery. Survival and short-term outcomes were compared between patients who had a Whipple procedure performed ≤12 weeks and > 12 weeks after completion of CR therapy. Results: 1610 patients met selection criteria. Average RS interval was 58.2 ± 39.5 days. 1419 patients had RS interval ≤12 weeks (mean 47.4 days) and 191 had RS interval > 12 weeks (mean 138.8 days). Age, race, gender, income, type of treatment facility, CA 19-9 levels, types of chemotherapy and radiation dosage administered were similar between the two groups. Mean tumor size was 32.2 mm in the ≤12 week group and 34.9 mm in the > 12...