title: Carcinoembryonic antigen has prognostic value for tumor downstaging and recurrence in rectal cancer after preoperative chemoradiotherapy and curative surgery: A multi-institutional and case-matched control study of KROG 14-12.
abstract: OBJECTIVE
  The Korean Radiation Oncology Group evaluated the significance of carcinoembryonic antigen (CEA) levels both as a predictor of tumor response after CRT and as a prognosticator for recurrence-free survival.
  
  
  METHODS
  1804 rectal cancer patients, staged cT3-4N0-2M0, participated in a multicenter study. The patients were administered preoperative radiation of 50.4 Gy in 28 fractions with 5-FU or capecitabine, followed by total mesorectal excision. Patients with elevated CEA levels (>5 ng/mL) were matched at a 1 (n=595):1 (n=595) ratio with patients with normal CEA (⩽5 ng/mL). The tumor response after CRT and the recurrence-free survival (RFS) rates were evaluated and compared between two arms.
  
  
  RESULTS
  An elevated CEA level (p<0.001) was determined to be a significant negative predictor of downstaging after CRT. The downstaging rate was 42.9% for normal CEA and 23.4% for elevated CEA. A multivariate analysis also revealed that cT (p=0.021) and cN classification (p=0.001), tumor size (p=0.002), and tumor location from the anal verge (p=0.006) were significant predictors for tumor downstaging. The 5-year RFS rates were significantly higher for the normal CEA arm than for the elevated CEA arm (74.2 vs. 63.5%, p<0.001).
  
  
  CONCLUSIONS
  Elevated CEA (>5 ng/mL) is a negative predictor of tumor downstaging after CRT and also has a negative impact on RFS in rectal cancer.
authors: Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea. Electronic address: koppul@catholic.ac.kr.
authors: Jong Hoon
authors: JH
authors: Lee
authors: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors: Dae Yong
authors: DY
authors: Kim
authors: Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea.
authors: Sung Hwan
authors: SH
authors: Kim
authors: Department of Surgery, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea.
authors: Hyeon Min
authors: HM
authors: Cho
authors: Department of Internal Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea.
authors: Byoung Yong
authors: BY
authors: Shim
authors: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors: Tae Hyun
authors: TH
authors: Kim
authors: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors: Sun Young
authors: SY
authors: Kim
authors: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors: Ji Yeon
authors: JY
authors: Baek
authors: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors: Jae Hwan
authors: JH
authors: Oh
authors: Department of Radiation Oncology, Chonnam National University Hospital, Republic of Korea.
authors: Taek Keun
authors: TK
authors: Nam
authors: Department of Radiation Oncology, Chonnam National University Hospital, Republic of Korea.
authors: Mee Sun
authors: MS
authors: Yoon
authors: Department of Radiation Oncology, Chonnam National University Hospital, Republic of Korea.
authors: Jae Uk
authors: JU
authors: Jeong
authors: Department of Radiation Oncology, Seoul National University Hospital, College of Medicine, Seoul, Republic of Korea.
authors: Kyubo
authors: K
authors: Kim
authors: Department of Radiation Oncology, Seoul National University Hospital, College of Medicine, Seoul, Republic of Korea.
authors: Eui Kyu
authors: EK
authors: Chie
authors: Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Hong Seok
authors: HS
authors: Jang
authors: Department of Radiation Oncology, Seoul National University Bundang Hospital, College of Medicine, Republic of Korea.
authors: Jae-Sung
authors: JS
authors: Kim
authors: Department of Radiation Oncology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Republic of Korea.
authors: Jin Hee
authors: JH
authors: Kim
authors: Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea.
authors: Bae Kwon
authors: BK
authors: Jeong
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000628:therapy*; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D000069287:Capecitabine / Q000008:administration & dosage; D002272:Carcinoembryonic Antigen / Q000378:metabolism*; D059248:Chemoradiotherapy / Q000379:methods*; D003131:Combined Modality Therapy; D004812:Epidemiologic Methods; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006268:Health Facilities; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D011300:Preoperative Care; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D002272:Carcinoembryonic Antigen; D000069287:Capecitabine; D005472:Fluorouracil
keywords: CEA; Chemoradiotherapy; Rectal cancer; Recurrence; Response