On the contray, unlike our expectation, overall diagnostic performance of the combination modality was not superior to endoscopy for the prediction of good tumor response. The reason for nonsynergistic effects of the combination modality may be explained by that the difficulties of anatomic imaging to adequately distinguish fibrotic tissue or local inflammation from residual tumor, making it difficult to evaluate tumor response accurately.[14] Accordingly, these inherent limitations may adversely affect the correlation between endoscopy and mrTRG. However, both endoscopy and combination modality had significantly higher PPVs for the prediction of ypT0 and ypT0-2 than those of MR tumor response. However, none of these methods did guarantee that a patient had good tumor response for definite candidates for organ-preserving surgery in current clinical practice. We think that future technical advances in endoscopy or mrTRG (e.g., pit pattern or magnified endoscopy, or a high Tesla magnetic field strength [7.0 T] system) may make it possible to preoperatively select candidates who can be treated by organ-preserving surgery, although these methods show limited diagnostic performance currently.