Effect of postoperative radiotherapy on survival in duodenal adenocarcinoma: a propensity score-adjusted analysis of Surveillance, Epidemiology, and End Results database

The use of adjuvant treatment has not been sufficiently investigated in duodenal adenocarcinoma. This study evaluated the effect of postoperative radiotherapy (PORT) on survival outcomes in this rare malignancy. We identified patients who were diagnosed between 2004 and 2013 in the Surveillance, Epidemiology, and End Results database. Overall survival (OS) and disease-specific survival (DSS) were analyzed before and after propensity score matching. Among the 701 eligible patients, 116 (17%) underwent PORT. There were no significant differences in OS and DSS according to receipt of PORT in the unmatched population (P = 0.982 and 0.496, respectively), whereas the propensity-matched analysis showed improved OS and DSS with PORT (P = 0.053 and 0.019, respectively). No receipt of PORT was an independent poor prognostic factor in multivariate analysis of both OS (P = 0.022) and DSS (P = 0.005). The potential survival benefits of PORT were observed in subgroups of T4 stage, larger tumor size, higher lymph node ratio, and total/radical resection. We provide useful insights into the therapeutic role of PORT in adenocarcinoma of the duodenum. Adjuvant strategy with PORT needs to be considered in locally advanced tumors.