Implications of Prolonged Time to Pancreaticoduodenectomy After Neoadjuvant Chemoradiation

Background For patients with pancreatic adenocarcinoma (PA), the optimal time interval between neoadjuvant chemoradiation (CR) to surgical resection has not been well established. Methods The National Cancer Database from 2006 to 2014 was queried for patients ≥18 y old diagnosed with PA who received neoadjuvant CR. Survival and short-term outcomes were compared between patients who had pancreaticoduodenectomy ≤12 wk and >12 wk after completion of CR. Results 1610 patients met selection criteria. Average radiation to surgery (RS) interval was 58.2 ± 39.5 d. 1419 patients had RS interval ≤12 wk (mean 47.4 d) and 191 had RS interval >12 wk (mean 138.8 d). Demographics, CA 19-9 levels, types of chemotherapy and radiation dosage were similar between the two groups. There were more patients with clinical stage III cancers in the >12 wk group than in the ≤12 wk group (33.5% versus 14%). Short-term outcomes were similar between the two groups. However, a long-term survival benefit was observed in the >12 wk group (median 25.8 versus 30.2 mo P = 0.049). An interval >12 wk was associated with significantly prolonged survival on multivariate analysis (HR: 0.80, 95% CI: 0.65-0.99; P = 0.042). Higher clinical stage and positive surgical margins were independently associated with worse survival. Conclusions Surgical resection beyond 12 wk after CR for PA did not worsen short-term outcomes. Waiting may contribute to better patient selection, especially those with locally advanced tumors. In the absence of progressive disease, patients need to be continuously evaluated for surgical resection after CR.