title: Predictive value of APAF-1 and COX-2 expression in pathologic complete response to neoadjuvant chemoradiotherapy for patients with locally advanced rectal adenocarcinoma.
abstract: OBJECTIVE
  To investigate predictive value of APAF-1 and COX-2 expression in pathologic complete response (pCR) for patients with rectal adenocarcinoma (RAC) who were treated with neoadjuvant chemoradiotherapy (neo-CRT) followed by total mesorectal excision (TME).
  
  
  METHODS
  Immunohistochemistry assay was used to detect expression of APAF-1 and COX-2 in paraffin-wax embedded tissues obtained before neo-CRT for patients with RAC. A 5-point tumor-regression grade (TRG) based on the ratio of residual tumor to fibrosis according to Dworak's scoring system was used to assess neo-CRT response. The relationship between expression of APAF-1 and COX-2 genes and pCR was explored.
  
  
  RESULTS
  pCR (TRG4) was observed in 23 patients (28.0%). pCR were more likely to be achieved for those with APAF-1 over-expression or lower expression of COX-2. pCR rate in patients with combination of high APAF-1 and low COX-2 expression was 56.0%, significantly higher than those with other combination of APAF1 and COX-2 expression. Multivariate analysis showed that over-expression of APAF-1 and suppressed expression of COX-2 were independent predictive factors for pCR.
  
  
  CONCLUSIONS
  Immunohistochemical evaluation of APAF-1 and COX-2 expression on pretreatment specimen may be used to predict pCR to neo-CRT in patients with RAC. The potential of the markers in monitoring pCR patient merits further investigation.
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.|Department of Radiation Oncology, Cancer Center of Guangzhou Medical University, Guangzhou 510075, China.
authors.forename: Haihua
authors.initials: H
authors.lastname: Peng
authors.affiliation: Department of Radiation Oncology, SunYat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Guangzhou 510060, China.|Department of Radiation Oncology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.
authors.forename: Kaiyun
authors.initials: K
authors.lastname: You
authors.affiliation: Department of Endoscopy and Laser, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Pathology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China.
authors.forename: Shaoyan
authors.initials: S
authors.lastname: Xi
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Pathology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China.
authors.forename: Muyan
authors.initials: M
authors.lastname: Cai
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.
authors.forename: Chengtao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Pathology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China.
authors.forename: Huizhong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Cancer Center of Guangzhou Medical University, Guangzhou 510075, China.
authors.forename: Tongchong
authors.initials: T
authors.lastname: Zhou
authors.affiliation: Department of Radiation Oncology, SunYat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Guangzhou 510060, China.
authors.forename: Yuanhong
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.
authors.forename: Bixiu
authors.initials: B
authors.lastname: Wen
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D000293:Adolescent; D000328:Adult; D000368:Aged; D053477:Apoptotic Protease-Activating Factor 1 / Q000032:analysis / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D017024:Chemotherapy, Adjuvant; D051546:Cyclooxygenase 2 / Q000032:analysis / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011237:Predictive Value of Tests; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D055815:Young Adult
chemical_list: C506592:APAF1 protein, human; D053477:Apoptotic Protease-Activating Factor 1; D014408:Biomarkers, Tumor; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human
keywords: APAF-1; COX-2; complete pathological response; neoadjuvant chemoradiotherapy; rectal adenocarcinoma