Yamashita S, et al. - This study aimed at assessing the prognostic impact of pathologic response to preoperative therapy on patients with duodenal adenocarcinoma (DA) and ampullary adenocarcinoma (AMPA). As per findings, the major pathologic response to preoperative therapy predicted improved disease-specific survival (DSS) after resection of DA and AMPA. Thereby suggesting its utility as new prognosticator after resection of DA and AMPA.