Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 14, 2015; 21(6): 1851-1856
Published online Feb 14, 2015. doi: 10.3748/wjg.v21.i6.1851
Tumor regression grades: Potential outcome predictor of locally advanced rectal adenocarcinoma after preoperative radiotherapy
Yi-Fan Peng, Wei-Dong Yu, Hong-Da Pan, Lin Wang, Ming Li, Yun-Feng Yao, Jun Zhao, Jin Gu
Yi-Fan Peng, Hong-Da Pan, Lin Wang, Ming Li, Yun-Feng Yao, Jun Zhao, Jin Gu, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Colorectal Surgery, Peking University Cancer Hospital and Institute, Beijing 100142, China
Wei-Dong Yu, Institute of Clinical Molecular Biology, People’s Hospital, Peking University, Beijing 100044, China
Author contributions: Yu WD and Peng YF contributed equally to this study, performed the majority of experiments, provided financial support, and were also involved in designing the study and writing the manuscript; Pan HD and Wang L provided vital reagents and analytical tools and were also involved in revising the manuscript; Li M, Yao YF, and Zhao J collected all the clinical materials; and Gu J designed the study and wrote the manuscript.
Supported by National Natural Science Foundation of China, No. 81372593, No. 81030040 and No. 81201965; Beijing Natural Science Foundation, No. 7132052; the National High Technology Research and Development Program of China (863 Program), No. 2012AA02A506 and No. SS2014AA020801; Beijing Municipal Administration of Hospitals Special Fund for Clinical Medicine Development, No. ZY201410; and Beijing Science and Technology Commission, No. D0905001000011 and No. D101100050010068.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Jin Gu, MD, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Colorectal Surgery, Peking University Cancer Hospital and Institute, 52 Fucheng Road, Haidian District, Beijing 100142, China. zlgujin@126.com
Telephone: +86-10-88196086 Fax: +86-10-88196238
Received: August 5, 2014
Peer-review started: August 5, 2014
First decision: September 15, 2014
Revised: September 29, 2014
Accepted: December 5, 2014
Article in press: December 8, 2014
Published online: February 14, 2015
Processing time: 190 Days and 8.1 Hours
Abstract

AIM: To analyze tumor regression grade (TRG) for prognosis of locally advanced rectal adenocarcinoma (LARA) treated with preoperative radiotherapy.

METHODS: One hundred and ninety patients with clinical stage II/III LARA were studied. All patients underwent radical surgery (between 2004 and 2010) after 30-Gy/10-fraction preoperative radiotherapy (pre-RT). All 190 patients received a short course of pre-RT and were reassessed for disease recurrence and survival; the slides of surgical specimens were reviewed and classified according to Mandard TRG. We compared patients with good response (Mandard TRG1 or TRG2) vs patients with bad/poor response (Mandard TRG3-5). Outcomes evaluated were 5-year overall survival (OS), 5-year disease-free survival (DFS), and local, distant and mixed recurrence. Fisher’s exact test or χ2 test, log-rank test and proportional hazards regression analysis were used to calculate the probability that Mandard TRG was associated with patient outcomes.

RESULTS: One hundred and sixty-six of 190 patients (87.4%) were identified as Mandard bad responders (TRG3-5). High Mandard grade was correlated with tumor height (41.7% < 6 cm vs 58.3% ≥ 6 cm, P = 0.050), ypT stage (75% ypT0-2 vs 25% ypT3-4, P = 0.000), and ypN stage (75% ypN0 vs 25% ypN1, P = 0.031). In univariate survival analysis, Mandard grade bad responders had significantly worse OS and DFS than good responders (TRG1/2) (OS, 83.1% vs 96.4%, P = 0.000; DFS, 72.3% vs 92.0%, P = 0.002). In multivariate survival analysis, Mandard bad responders had significantly worse DFS than Mandard good responders (DFS 3.8 years (95%CI: 1.2-12.2 years, P = 0.026).

CONCLUSION: Mandard grade good responders had a favorable prognosis. TRG may be a potential predictor for DFS in LARA after pre-RT.

Keywords: Tumor regression grade; Preoperative radiotherapy; Rectal adenocarcinoma; Disease-free survival

Core tip: We report that Mandard tumor regression grade (TRG) predicted the outcome of locally advanced rectal adenocarcinoma after preoperative radiotherapy. We examined the correlation of TRG in the prognosis of rectal adenocarcinoma. We found that high Mandard grade was correlated with tumor height, ypT stage, and ypN stage in Mandard poor responders. In univariate survival analysis, Mandard bad responders had significantly worse overall survival and disease-free survival (DFS) compared with Mandard good responders. In multivariate survival analysis, Mandard bad responders had significantly worse DFS than Mandard good responders. Mandard good responders had a favorable prognosis.