title: Significance of histologic tumor grade in rectal cancer treated with preoperative chemoradiotherapy followed by curative surgery: A multi-institutional retrospective study.
abstract: OBJECTIVE
  To evaluate the pre-treatment clinical factors affecting recurrence and survival in rectal cancer patients who receive preoperative chemoradiotherapy (CRT) and curative surgery.
  
  
  METHODS
  The clinical data of 1782 patients from 8 institutions in Korea were analyzed. The potential prognostic factors that could be acquired before radical surgery were patient age, gender, clinical T and N stages, tumor size and location, tumor grade, carcinoembryonic antigen (CEA) level, and the concurrent chemotherapy regimen. The relapse-free survival (RFS), overall survival (OS), and cumulative incidence of locoregional and distant recurrence were analyzed according to the clinical factors.
  
  
  RESULTS
  Among the pre-treatment clinical factors, tumor grade, pre-CRT CEA level, tumor location, and clinical N stage were significant prognostic factors affecting the RFS. The high-grade tumor was the hazardous factor for RFS on the multivariate analysis [Hazard ratio (HR), 1.83; 95% confidence interval (CI), 1.29-2.58; p=0.001]. The 5-year RFS rate for high-grade tumors was significantly lower than that for low-grade tumors (63.8% vs. 78.8%, p<0.001). The tumor grade was a significant prognostic factor for distant recurrence (HR, 1.83, 95% CI, 1.29-2.58; p<0.001), but not for locoregional recurrence (HR, 1.49, 95% CI, 0.68-3.26; p=0.320) on the multivariate analysis. The 5-year OS rate for high-grade tumors was significantly lower than that for low-grade tumors (70.6% vs. 85.5%, p<0.001).
  
  
  CONCLUSIONS
  The tumor grade is the significant pre-treatment clinical factor for recurrence and survival in rectal cancer patients who receive preoperative CRT and curative surgery.
authors.affiliation: Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea; Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea.
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Song
authors.affiliation: Department of Radiation Oncology, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea.
authors.forename: Sung Hwan
authors.initials: SH
authors.lastname: Kim
authors.affiliation: 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.forename: Jong Hoon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Surgery, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea.
authors.forename: Hyeon Min
authors.initials: HM
authors.lastname: Cho
authors.affiliation: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors.forename: Dae Yong
authors.initials: DY
authors.lastname: Kim
authors.affiliation: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Baek
authors.affiliation: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Oh
authors.affiliation: Department of Radiation Oncology, Chonnam National University Hospital, Hwasun, Republic of Korea.
authors.forename: Taek Keun
authors.initials: TK
authors.lastname: Nam
authors.affiliation: Department of Radiation Oncology, Chonnam National University Hospital, Hwasun, Republic of Korea.
authors.forename: Mee Sun
authors.initials: MS
authors.lastname: Yoon
authors.affiliation: Department of Radiation Oncology, Chonnam National University Hospital, Hwasun, Republic of Korea.
authors.forename: Jae Uk
authors.initials: JU
authors.lastname: Jeong
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyubo
authors.initials: K
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Eui Kyu
authors.initials: EK
authors.lastname: Chie
authors.affiliation: Department of Radiation Oncology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Hong Seok
authors.initials: HS
authors.lastname: Jang
authors.affiliation: Department of Radiation Oncology, Seoul National University Bundang Hospital, College of Medicine, Bundang, Republic of Korea.
authors.forename: Jae Sung
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Republic of Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Republic of Korea.
authors.forename: Ki Mun
authors.initials: KM
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D002272:Carcinoembryonic Antigen / Q000097:blood; D059186:Chemoradiotherapy, Adjuvant / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy / Q000379:methods; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery / Q000628:therapy; D012008:Recurrence; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D002272:Carcinoembryonic Antigen
keywords: Grade; Histology; Neoplasm; Prognosis; Rectum