title: Serum CEA as a predictor for the response to preoperative chemoradiation in rectal cancer.
abstract: OBJECTIVE
  Recent data suggest that good responders to preoperative chemoradiation (CRT) have a favorable prognosis in rectal cancer patients. The aim of this study was to investigate the predictive value of serum carcinoembryonic antigen (CEA) levels for the tumor response to preoperative CRT in rectal cancer patients.
  
  
  METHODS
  The study comprised 141 rectal adenocarcinoma patients who underwent preoperative radiotherapy with 5-fluorouracil (FU) based chemotherapy, followed by radical surgery. The staging workup was consisted of endorectal ultrasound, abdominopelvic computed tomography scan, or magnetic resonance imaging. The outcome parameters were cancer-specific survival and disease-free survival. Pre-CRT clinicopathologic features, including age, gender, location of the tumor, clinical tumor (cT) classification, clinical nodal (cN) classification, and serum CEA levels were investigated as possible predictors for the response to preoperative CRT.
  
  
  RESULTS
  Pathologic complete or near complete responses (good responders, GR) occurred in 26 (19%) patients, while partial or no response (poor responders, PR) occurred in the remaining 115 (81%) patients. GR showed better cancer-specific survival (P = 0.028) and disease-free survival rates (P = 0.011) than PR. Univariate analysis revealed that positive cN and elevated (>5 ng/ml) pre-CRT serum CEA levels are associated with poor tumor response to preoperative CRT. Using logistic regression analysis, elevated pre-CRT serum CEA levels were the only significant predictor for the poor response to CRT (Odd ratio = 2.876, 95% confidence interval = 1.04-7.46, P = 0.041).
  
  
  CONCLUSIONS
  Our data suggest that elevated pre-CRT serum CEA levels are associated with poor tumor response to CRT. Therefore, pre-CRT serum CEA levels provide useful information about tumor response to preoperative CRT in rectal cancer patients.
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yoon-Ah
authors.initials: YA
authors.lastname: Park
authors.forename: Seung-Kook
authors.initials: SK
authors.lastname: Sohn
authors.forename: Jinsil
authors.initials: J
authors.lastname: Seong
authors.forename: Seung-Hyuk
authors.initials: SH
authors.lastname: Baik
authors.forename: Kang-Young
authors.initials: KY
authors.lastname: Lee
authors.forename: Nam-Kyu
authors.initials: NK
authors.lastname: Kim
authors.forename: Chang-Whan
authors.initials: CW
authors.lastname: Cho
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood*; D003131:Combined Modality Therapy; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012004:Rectal Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D005472:Fluorouracil