title: Evaluation of treatment response and tissue necrosis as prognostic indicators following neoadjuvant chemoradiotherapy in rectal cancer patients.
abstract: OBJECTIVE
  The objective of this study was to assess the prognostic roles of treatment response and tissue necrosis after chemoradiotherapy (CRT) in locally advanced rectal cancer.
  
  
  METHODS
  A total of 243 patients with locally advanced rectal cancer who underwent neoadjuvant CRT were included. Three treatment response groups were classified by their pathological stage results: complete treatment response (CTR), intermediate treatment response (ITR), and poor treatment response (PTR). Three tissue necrosis groups were classified based on tissue pathological results: complete necrosis response (CNR), intermediate necrosis response (INR), and poor necrosis response (PNR).
  
  
  RESULTS
  Overall survival (OS) and recurrence-free survival (RFS) rate at three years were 74.5% and 61.3%, respectively. The 3-year OS rates of the CTR, ITR, and PTR groups were 83.7%, 75.9%, and 69.7%, respectively (p < 0.001); the 3-year RFS rates were 76.7%, 69.0%, and 52.1%, respectively (p < 0.001). The 3-year OS rates of the CNR, INR, and PNR groups were 83.7%, 80.6%, and 61.8%, respectively (p < 0.001); the 3-year RFS rates were 76.7%, 68.9%, and 44.3%, respectively (p < 0.001). When compared to CTR/CNR, PTR/PNR was strongly related to an increased risk of recurrence (hazard ratio [HR], 5.53; 95% confidence interval [CI], 2.01 to 15.23 vs. HR, 6.37; 95% CI, 2.29 to 17.74, respectively) in univariate Cox regression. Both PTR and PNR were strongly associated with shorter RFS and OS when compared with CTR and CNR in the multivariate Cox regression.
  
  
  CONCLUSIONS
  Tissue necrosis is an equally important prognostic marker as treatment response for oncologic outcomes in locally advanced rectal cancer.
authors.affiliation: Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ji-Han
authors.initials: JH
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Ho Jung
authors.initials: HJ
authors.lastname: An
authors.affiliation: Department of General Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Hyung-Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jonghoon
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Kang-Moon
authors.initials: KM
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sung Hwan
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of General Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Hyeon-Min
authors.initials: HM
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Byoung Yong
authors.initials: BY
authors.lastname: Shim
mesh_terms: D000368:Aged; D001706:Biopsy; D059186:Chemoradiotherapy, Adjuvant / Q000009:adverse effects / Q000401:mortality; D016009:Chi-Square Distribution; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D010535:Laparoscopy / Q000009:adverse effects / Q000401:mortality; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009336:Necrosis; D020360:Neoadjuvant Therapy / Q000009:adverse effects / Q000401:mortality; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D012074:Remission Induction; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
keywords: Chemoradiotherapy; Necrosis; Rectal neoplasms