title: Predictors and patterns of recurrence after curative liver resection in intrahepatic cholangiocarcinoma, for application of postoperative radiotherapy: a retrospective study.
abstract: BACKGROUND
  The majority of patients with intrahepatic cholangiocarcinoma (IHCC) who undergo complete tumor resection subsequently develop tumor recurrence. The objectives of this study were to determine the risk factors for IHCC recurrence after curative (R0) liver resection and to identify the feasibility about postoperative adjuvant radiation therapy (RT).
  
  
  METHODS
  We retrospectively reviewed patients who underwent liver resection for IHCC between April 1995 and December 2012 at Samsung Medical Center. Cox regression analysis was performed to determine risk factors of recurrence. Patients with a recurrence in remnant liver within 2 cm from the resection margin, with or without locoregional lymph node (LN) metastases, were considered as potential RT candidates. Center-of-mass (COM) distances between the recurrent cancers and the cut surface were measured with MATLAB.
  
  
  RESULTS
  We included 153 out of 198 patients who underwent partial liver resection for IHCC. About two thirds (n=93, 60.8%) of patients developed recurrent disease. The median recurrence-free survival (RFS) was 14 months (range, 0-204). Tumor size≥4.0 cm, LN metastasis and multiple tumors were significant predictors of IHCC recurrence on multivariate analysis. Tumor size≥5.0 cm was the only factor associated with recurrence beyond the RT field in patients with recurrence. Among 93 patients with recurrence, 16 (17.2%) patients were recurred in the RT field.
  
  
  CONCLUSIONS
  After curative resection in IHCC, more than 60% of patients recurred, and among recurred patients, 17.2% were recurred within the RT field. Consequently, for control of locoregional recurrence, adjuvant RT could be carefully considered in patients with recurrence factors. Especially, patients with a tumor size larger than 5 cm should be judiciously selected for adjuvant RT.
authors.affiliation: Department of Critical Care Medicine, Sungkyunkwan University School of Medicine, 50 Irowndong, Gangnam-gu, Seoul, 135-170, South Korea.
authors.forename: Eunmi
authors.initials: E
authors.lastname: Gil
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-170, South Korea. jwjoh@skku.edu.
authors.forename: Jae-Won
authors.initials: JW
authors.lastname: Joh
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-170, South Korea. hee.ro.park@samsung.com.
authors.forename: Hee Chul
authors.initials: HC
authors.lastname: Park
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-170, South Korea.
authors.forename: Jeong Il
authors.initials: JI
authors.lastname: Yu
authors.affiliation: Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-170, South Korea.
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Jung
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-170, South Korea.
authors.forename: Jong Man
authors.initials: JM
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D018281:Cholangiocarcinoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006498:Hepatectomy / Q000401:mortality*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D009367:Neoplasm Staging; D011379:Prognosis; D011880:Radiotherapy Planning, Computer-Assisted; D012189:Retrospective Studies; D015996:Survival Rate