Comparison of overall survival between preoperative chemotherapy and chemoradiotherapy for resectable pancreatic adenocarcinoma

Background: Preoperative therapy is being increasingly used in the treatment of resectable pancreatic cancer. Because there are only limited data on the optimal preoperative regimen, we compared overall survival (OS) between preoperative chemotherapy (CT) and preoperative chemoradiotherapy (CRT) in resectable pancreatic adenocarcinoma. Patients and Methods: Patients receiving preoperative therapy and resection for clinical T1–3N0–1M0 adenocarcinoma of the pancreas were identified in the National Cancer Database for 2006 through 2012. We constructed inverse probability of treatment weights to balance baseline group differences, and compared OS between CT and CRT, as well as pathologic and postoperative findings. Results: We identified 1,326 patients (CT: 616; CRT: 710). Differences in OS were not significant between CRT and CT (median survival, 25 vs 26 months; P=.10; weight-adjusted hazard ratio, 0.89; 95% CI, 0.77–1.02). Compared with patients in the CT group, those in the CRT group had lower pathologic T stage (ypT0/T1/T2: 36% vs 21%; P<.01), less lymph node involvement (ypN1: 35% vs 59%; P<.01), and fewer positive resection margins (14% vs 21%; P=.01), but had more postoperative unplanned readmissions (9% vs 6%; P=.01) and increased 90-day mortality (7% vs 4%; P=.03). Those in the CRT group were also less likely to receive postoperative therapy (26% vs 51%; P<.01). Conclusions: Preoperative CT and CRT have similar OS, but CRT is associated with more favorable pathologic features at the cost of higher postoperative morbidity and mortality. Additional trials investigating preoperative therapy are needed for patients with resectable pancreatic cancer.