title: Can serum dynamics of carcinoembryonic antigen level during neoadjuvant chemoradiotherapy in rectal cancer predict tumor response and recurrence? A multi-institutional retrospective study.
abstract: OBJECTIVE
  We evaluate whether the change of carcinoembryonic antigen (CEA) level before and after preoperative chemoradiotherapy (CRT) in rectal cancer affects tumor response and recurrence or not.
  
  
  METHODS
  We retrospectively analyzed 1447 rectal cancer patients who underwent preoperative CRT followed by curative surgery. All patients received preoperative radiotherapy of 50.4 Gy in 28 fractions with 5-fluorouracil or capecitabine. Total mesorectal excision was performed 4 to 8 weeks after preoperative CRT. CEA levels were checked before and after CRT. Clinical and pathologic factors were analyzed for tumor response and recurrence.
  
  
  RESULTS
  Post-CRT CEA level (cutoff value, 2.5 ng/mL) was not a significant factor for tumor response on the multivariate analysis (p = 0.095). Patients were categorized according to the pre- and post-CRT CEA level (group A: pre-CRT CEA ≤5 ng/mL; group B: pre-CRT CEA >5 ng/mL and post-CRT CEA ≤2.5 ng/mL; group C: pre-CRT CEA >5 ng/mL and post-CRT CEA >2.5 ng/mL). The relapse-free survival (RFS) at 5 years was significantly higher in group A than in groups B and C (82.6 vs. 73.7 % vs. 72.2 %, p < 0.001). The overall survival (OS) at 5 years was significantly higher in group A than in groups B and C (90.1 vs. 84.4 % vs. 83.4 %, p < 0.001). However, there is no significant difference for RFS and OS between groups B and C (all, p > 0.05).
  
  
  CONCLUSIONS
  Decline of elevated CEA level (>5 ng/mL) during preoperative chemoradiotherapy has no significant effect on tumor response and recurrence in rectal cancer.
authors.affiliation: Department of Radiation Oncology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Mi Joo
authors.initials: MJ
authors.lastname: Chung
authors.affiliation: Department of Radiation Oncology, Chonnam National University Medical School, Gwangju, South Korea.
authors.forename: Taek Keun
authors.initials: TK
authors.lastname: Nam
authors.affiliation: Department of Radiation Oncology, Chonnam National University Medical School, Gwangju, South Korea.
authors.forename: Jae Uk
authors.initials: JU
authors.lastname: Jeong
authors.affiliation: Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, 442-723, 93-6, Ji-dong, Paldal-gu, Suwon, Kyeonggi-do, Republic of Korea.
authors.forename: Sung Hwan
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Ewha Woman's University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kyubo
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Hong Seok
authors.initials: HS
authors.lastname: Jang
authors.affiliation: Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea.
authors.forename: Bae Kwon
authors.initials: BK
authors.lastname: Jeong
authors.affiliation: Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, 442-723, 93-6, Ji-dong, Paldal-gu, Suwon, Kyeonggi-do, Republic of Korea. koppul@catholic.ac.kr.
authors.forename: Jong Hoon
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000368:Aged; D002272:Carcinoembryonic Antigen / Q000097:blood*; D059186:Chemoradiotherapy, Adjuvant; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D012372:ROC Curve; D012004:Rectal Neoplasms / Q000097:blood* / Q000628:therapy*; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D002272:Carcinoembryonic Antigen
keywords: CEA; Chemoradiotherapy; Rectal cancer; Recurrence; Response