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

PURPOSE: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.