title: Reappraisal of pretreatment carcinoembryonic antigen in patients with rectal cancer receiving preoperative chemoradiotherapy.
abstract: OBJECTIVE
  The pretreatment serum carcinoembryonic antigen (CEA) level is an independent prognostic factor in colorectal cancer. We aimed to investigate the significance of CEA as a prognostic or predictive factor in rectal cancer patients receiving preoperative chemoradiotherapy (CRT).
  
  
  METHODS
  In total, 609 patients with locally advanced (cStage II-III) mid to distal rectal cancer who underwent preoperative CRT and radical surgery between 2001 and 2008 were analyzed retrospectively. Predictive factors for pathologic CRT response were determined using multivariate logistic regression. A prognostic factor analysis was performed using the log-rank test and Cox proportional hazards regression.
  
  
  RESULTS
  Elevated CEA levels (>5 ng/mL) were observed in 201 (33.0%) patients at diagnosis. Following preoperative CRT, downstaging (ypStage 0-I) occurred in 255 (41.9%) patients, of whom 88 had pathologic complete tumor regression. Pretreatment CEA was significantly associated with pathologic CRT response in terms of downstaging and tumor regression grade, and was the most relevant predictive factor. After a median follow-up period of 60 months, the 5-year disease-free and overall survival rates were 76.2% and 84.6%, respectively. Prognostic factors independently associated with recurrence or survival included ypStage, circumferential resection margin, and histologic grade.
  
  
  CONCLUSIONS
  In patients with rectal cancer who received preoperative CRT, the pretreatment CEA level was a significant and independent predictor of pathologic CRT response. However, it may not be able to predict long-term outcomes independently of ypStage.
authors.affiliation: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Seung-Gu
authors.initials: SG
authors.lastname: Yeo
authors.forename: Dae Yong
authors.initials: DY
authors.lastname: Kim
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Chang
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Park
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Oh
authors.forename: Byung Chang
authors.initials: BC
authors.lastname: Kim
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Baek
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000473:pathology / Q000628:therapy*; 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*; D059186:Chemoradiotherapy, Adjuvant; D018572:Disease-Free Survival; D005163:Factor Analysis, Statistical; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000097:blood* / Q000473:pathology / Q000628:therapy*; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen