title: Factors influencing survival outcome for radiotherapy for biliary tract cancer: a multicenter retrospective study.
abstract: OBJECTIVE
  To seek for the possible factors influencing overall survival (OS) with radiotherapy (RT) for biliary tract cancer.
  
  
  METHODS
  Data were collected retrospectively from RT database of 31 institutions in Japan. All patients underwent at least external beam RT. The factors influencing OS were investigated.
  
  
  RESULTS
  Data of 498 patients were analyzed. Median OS of the 212 patients who underwent surgery was significantly better than that of the 286 patients without surgery (31 vs. 15 months, p<0.001). The OS for the R0 or R1 resection group was significantly longer than that for the R2 or non-surgery group, as well as for n0 compared to n1 (all p<0.001). Chemoradiotherapy (CRT), both sequential and concurrent, resulted in a better OS than RT alone for the n1 group (31 vs. 13 months, p<0.001), and marginally better for the R0/R1 group (p=0.065; p=0.054 for concurrent CRT). However, no such benefit was observed for the R2/non-surgical patients. Multivariate analysis identified performance status, clinical stage, and surgery as significant factors.
  
  
  CONCLUSIONS
  Surgery, especially R0/R1 resection, seemed as the gold standard for treatment of biliary tract cancer including RT, even in the highly heterogeneous population obtained from the multicenter retrospective study. The possibility was shown that CRT yielded better survival benefit especially for n1 patients. We recommend that future prospective trials include an arm of adjuvant CRT at least for n1 and possibly R0/R1 patients.
authors.affiliation: Department of Radiation Oncology, Osaka University Graduate School of Medicine, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshioka
authors.affiliation: Department of Radiation Oncology, Osaka University Graduate School of Medicine, Japan. Electronic address: kogawa@radonc.med.osaka-u.ac.jp.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Department of Radiology, Iwate Medical University, Japan.
authors.forename: Hirobumi
authors.initials: H
authors.lastname: Oikawa
authors.affiliation: Department of Radiology, University of Yamanashi, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Onishi
authors.affiliation: Department of Radiation Oncology, Shimane University, Japan.
authors.forename: Nobue
authors.initials: N
authors.lastname: Uchida
authors.affiliation: Department of Radiology, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Toshiya
authors.initials: T
authors.lastname: Maebayashi
authors.affiliation: Department of Radiology, Tokyo Medical University, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Kanesaka
authors.affiliation: Department of Radiation Oncology, Nara Medical University of Medicine, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Tamamoto
authors.affiliation: Division of Radiation Oncology, Shizuoka Cancer Center, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Asakura
authors.affiliation: Department of Radiology, Hamamatsu University School of Medicine, Shizuoka, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kosugi
authors.affiliation: Department of Radiation Oncology, Chiba Cancer Center, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hatano
authors.affiliation: Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Yoshimura
authors.affiliation: Department of Radiation Oncology, Seirei Mikatahara General Hospital, Shizuoka, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Heavy Particle Therapy and Radiation Oncology, Saga University, Japan.
authors.forename: Sunao
authors.initials: S
authors.lastname: Tokumaru
authors.affiliation: Department of Radiation Oncology, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Sekiguchi
authors.affiliation: Department of Radiology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Department of Radiation Oncology, Hyogo Cancer Center, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Soejima
authors.affiliation: Department of Radiation Oncology, Osaka University Graduate School of Medicine, Japan.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Isohashi
authors.affiliation: Department of Radiation Oncology, Yamagata University, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Nemoto
authors.affiliation: Department of Radiation Oncology, Kinki University Faculty of Medicine, Osaka, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Nishimura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001661:Biliary Tract Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D059248:Chemoradiotherapy; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
keywords: Adjuvant therapy; Biliary tract cancer; Chemoradiation; Definitive therapy; Radiation therapy