title: Clinical significance of pre- to post-chemoradiotherapy s-CEA reduction ratio in rectal cancer patients treated with preoperative chemoradiotherapy and curative resection.
abstract: OBJECTIVE
  To evaluate the clinical significance of a reduction in serum carcinoembryonic antigen (s-CEA) concentration ratio from before to after preoperative chemoradiotherapy (CRT) in terms of recurrence and prognostic factors in rectal cancer patients.
  
  
  METHODS
  We retrospectively evaluated 333 rectal cancer patients who received preoperative CRT followed by surgery with curative intent between January 2000 and December 2006. Patients were divided into three groups: those with pre-CRT s-CEA≤6 ng/mL (group 1), those with pre-CRT s-CEA>6 mg/mL and post-CRT s-CEA≥70% lower than pre-CRT s-CEA (group 2), and those with pre-CRT s-CEA>6 mg/mL and post-CRT s-CEA<70% lower or higher than pre-CRT s-CEA (group 3).
  
  
  RESULTS
  The 5-year disease-free survival rate was similar in group 1 (76.0%) and group 2 (66.0%), but significantly lower in group 3 (39.5%) (p<0.001). Multivariate analysis showed that CEA group 3, ypT stage, ypN stage, and type of surgery were independent prognostic factors for disease-free survival.
  
  
  CONCLUSIONS
  The reduction ratio of pre- to post-CRT s-CEA concentration may be an independent prognostic factor for disease-free survival following preoperative CRT and surgery in rectal cancer patients with initial s-CEA>6 ng/mL.
authors.affiliation: Department of Colon & Rectal Surgery, University of Ulsan College of Medicine and Asan Medical Center, Songpa-Ku, Seoul, Korea.
authors.forename: Chan Wook
authors.initials: CW
authors.lastname: Kim
authors.forename: Chang Sik
authors.initials: CS
authors.lastname: Yu
authors.forename: Song-Soo
authors.initials: SS
authors.lastname: Yang
authors.forename: Kyung Ho
authors.initials: KH
authors.lastname: Kim
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Yoon
authors.forename: Sang Nam
authors.initials: SN
authors.lastname: Yoon
authors.forename: Seok-Byung
authors.initials: SB
authors.lastname: Lim
authors.forename: Jin Cheon
authors.initials: JC
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D000069287:Capecitabine; D002272:Carcinoembryonic Antigen / Q000378:metabolism*; D059248:Chemoradiotherapy; D003131:Combined Modality Therapy; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000031:analogs & derivatives; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D009367:Neoplasm Staging; D011379:Prognosis; D012004:Rectal Neoplasms / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult
chemical_list: D002272:Carcinoembryonic Antigen; D003841:Deoxycytidine; D000069287:Capecitabine; D005472:Fluorouracil