title: A multicenter analysis of adjuvant therapy after surgery for stage IIIC endometrial adenocarcinoma: A Korean Radiation Oncology Group study (KROG 13-17).
abstract: OBJECTIVE
  To investigate whether combined chemoradiotherapy (CTRT) confers a benefit for survival outcome over radiotherapy (RT) alone after primary surgery in patients with FIGO stage IIIC endometrial adenocarcinoma.
  
  
  METHODS
  We conducted a multicenter retrospective study of patients with surgical stage IIIC endometrial cancer from 1990 to 2011. Adjuvant RT alone was performed in 85 patients (40.3%) and adjuvant CTRT in 126 patients (59.7%). Disease-free survival (DFS) and overall survival (OS) were analyzed using Kaplan-Meier method and Cox proportional hazards model.
  
  
  RESULTS
  Stage IIIC1 and stage IIIC2 accounted for 63% and 37%, respectively. FIGO IIIC2 had a higher recurrence rate than FIGO IIIC1 (38.5% vs. 29.3%, p=0.172). Five-year OS and DFS were lower in FIGO IIIC2 than FIGO IIIC1 (85.1% vs. 76.9%, p=0.417; 71.0% vs. 59.2%, p=0.108, respectively). Eighteen patients (13.5%) in stage IIIC1 developed PALN recurrence, whereas only one (3.3%) in stage IIIC2 had PALN recurrence (p=0.001). In multivariate analysis, predictors of DFS were parametrial invasion (HR, 3.49; 95% CI, 1.83-6.64; p<0.001), higher grade (HR, 2.78; 95% CI, 1.31-5.89; p=0.008), and >3 positive pelvic nodes (HR, 1.84; 95% CI, 1.11-3.05; p=0.019). Combined CTRT did not affect DFS or OS in IIIC1 and IIIC2 compared with RT alone.
  
  
  CONCLUSIONS
  CTRT showed comparable survival outcome to RT alone. Half of relapses (46%) in stage IIIC1 occurred in PALN region, whereas relapse in stage IIIC2 primarily occurred in distant metastasis (90%). Future randomized studies are needed to determine which subgroup may be most likely to benefit from CCRT.
authors.affiliation: Department of Radiation Oncology, Chonnam National University Hwasun Hospital, Chonnam National University Medical School, Jeollanam-do, Republic of Korea.
authors.forename: Mee Sun
authors.initials: MS
authors.lastname: Yoon
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Electronic address: wonro.park@samsung.com.
authors.forename: Won
authors.initials: W
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Huh
authors.affiliation: Department of Radiation Oncology, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Hak Jae
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Young Seok
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Yong Bae
authors.initials: YB
authors.lastname: Kim
authors.affiliation: Center for Uterine Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Republic of Korea.
authors.forename: Joo-Young
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, St. Vincent's Hospital, The Catholic University of Korea, College of Medicine, Suwon, Republic of Korea.
authors.forename: Jong-Hoon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Inha University School of Medicine, Incheon, Republic of Korea.
authors.forename: Hun Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
authors.forename: Jihye
authors.initials: J
authors.lastname: Cha
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, Cheil General Hospital and Women's Healthcare Center, Kwandong University, College of Medicine, Seoul, Republic of Korea.
authors.forename: Juree
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Won Sup
authors.initials: WS
authors.lastname: Yoon
authors.affiliation: Department of Radiation Oncology, Chung-Ang University Hospital, Seoul, Republic of Korea.
authors.forename: Jin Hwa
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: Mison
authors.initials: M
authors.lastname: Chun
authors.affiliation: Department of Radiation Oncology, Dong-A University School of Medicine, Busan, Republic of Korea.
authors.forename: Youngmin
authors.initials: Y
authors.lastname: Choi
authors.affiliation: Department of Radiation Oncology, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea.
authors.forename: Sei Kyung
authors.initials: SK
authors.lastname: Chang
authors.affiliation: Department of Radiation Oncology, University of Wonkwang School of Medicine, Iksan, Republic of Korea.
authors.forename: Kang Kyoo
authors.initials: KK
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Incheon St. Marys Hospital, The Catholic University of Korea, Incheon, Republic of Korea.
authors.forename: Myungsoo
authors.initials: M
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059186:Chemoradiotherapy, Adjuvant; D018572:Disease-Free Survival; D016889:Endometrial Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D055815:Young Adult
keywords: Adjuvant chemoradiotherapy; Adjuvant radiotherapy; Endometrial cancer