title: Tumor regression grades: potential outcome predictor of locally advanced rectal adenocarcinoma after preoperative radiotherapy.
abstract: OBJECTIVE
  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 χ(2) 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).
  
  
  CONCLUSIONS
  Mandard grade good responders had a favorable prognosis. TRG may be a potential predictor for DFS in LARA after pre-RT.
authors: 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.
authors: Yi-Fan
authors: YF
authors: Peng
authors: 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.
authors: Wei-Dong
authors: WD
authors: Yu
authors: 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.
authors: Hong-Da
authors: HD
authors: Pan
authors: 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.
authors: Lin
authors: L
authors: Wang
authors: 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.
authors: Ming
authors: M
authors: Li
authors: 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.
authors: Yun-Feng
authors: YF
authors: Yao
authors: 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.
authors: Jun
authors: J
authors: Zhao
authors: 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.
authors: Jin
authors: J
authors: Gu
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery; D000368:Aged; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D018714:Radiotherapy, Adjuvant; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
keywords: Disease-free survival; Preoperative radiotherapy; Rectal adenocarcinoma; Tumor regression grade