Pathologic Stage Following Preoperative Chemoradiotherapy Underestimates the Risk of Developing Distant Metastasis in Rectal Cancer: A Comparison to Staging Without Preoperative Chemoradiotherapy

Background and Objectives: There is still little evidence of a relationship between pathologic stage with or without preoperative chemoradiotherapy (CRT) in rectal cancer. The aim of this study was to investigate the prognostic implication of the preoperative-CRT pathologic stage (ypStage) by comparing it to the pathologic stage without preoperative-CRT (pStage). Methods: Between July 2004 and December 2012, 774 consecutive patients who received radical surgery for histologically diagnosed rectal adenocarcinoma (clinical stage I-III) were included. Results: A total of 674 surviving patients were followed-up for a median of 43.4 months. Five-year local recurrence (LR) -free survival rates were similar for each ypStage and the corresponding pStage. In contrast, 5-year distant metastasis (DM) -free survival rates were poorer for each ypStage than for the corresponding pStage. The hazard ratio increased with a decrease in pathological stages (Stage I: 3.5, Stage II: 2.2, and Stage III: 1.4). Conclusions: ypStage in rectal cancer is a good prognostic factor in predicting LR and DM. Although the ypStage can stratify patients according to the risk of developing DM, the risk as determined by the ypStage could be higher than that of corresponding pStage, especially in patients showing a higher degree of downstaging. (C) 2016 Wiley Periodicals, Inc.