title: Patterns of failure and prognostic factors in resected extrahepatic bile duct cancer: implication for adjuvant radiotherapy.
abstract: OBJECTIVE
  To find the applicability of adjuvant radiotherapy for extrahepatic bile duct cancer (EBDC), we analyzed the pattern of failure and evaluate prognostic factors of locoregional failure after curative resection without adjuvant treatment.
  
  
  METHODS
  In 97 patients with resected EBDC, the location of tumor was classified as proximal (n = 26) and distal (n = 71), using the junction of the cystic duct and common hepatic duct as the dividing point. Locoregional failure sites were categorized as follows: the hepatoduodenal ligament and tumor bed, the celiac artery and superior mesenteric artery, and other sites.
  
  
  RESULTS
  The median follow-up time was 29 months for surviving patients. Three-year locoregional progression-free survival, progression-free survival, and overall survival rates were 50%, 42%, and 52%, respectively. Regarding initial failures, 79% and 81% were locoregional failures in proximal and distal EBDC patients, respectively. The most common site was the hepatoduodenal ligament and tumor bed. In the multivariate analysis, perineural invasion was associated with poor locoregional progression-free survival (p = 0.023) and progression-free survival (p = 0.012); and elevated postoperative CA19-9 (≥37 U/mL) did with poor locoregional progression-free survival (p = 0.002), progression-free survival (p < 0.001) and overall survival (p < 0.001).
  
  
  CONCLUSIONS
  Both proximal and distal EBDC showed remarkable proportion of locoregional failure. Perineural invasion and elevated postoperative CA19-9 were risk factors of locoregional failure. In these patients with high risk of locoregional failure, adjuvant radiotherapy could be considered to improve locoregional control.
authors: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors: Tae Ryool
authors: TR
authors: Koo
authors: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors: Keun-Yong
authors: KY
authors: Eom
authors: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors: In Ah
authors: IA
authors: Kim
authors: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors: Jai Young
authors: JY
authors: Cho
authors: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors: Yoo-Seok
authors: YS
authors: Yoon
authors: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors: Dae Wook
authors: DW
authors: Hwang
authors: Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.
authors: Ho-Seong
authors: HS
authors: Han
authors: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.
authors: Jae-Sung
authors: JS
authors: Kim
keywords: Bile duct neoplasms; Prognosis; Recurrence; Survival analysis