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World J Clin Cases. Jun 6, 2019; 7(11): 1242-1252
Published online Jun 6, 2019. doi: 10.12998/wjcc.v7.i11.1242
Radiation therapy for extrahepatic bile duct cancer: Current evidences and future perspectives
Taeryool Koo, Hae Jin Park, Kyubo Kim
Taeryool Koo, Department of Radiation Oncology, Hallym University Sacred Heart Hospital, Anyang 14068, South Korea
Hae Jin Park, Department of Radiation Oncology, Hanyang University College of Medicine, Seoul 04763, South Korea
Kyubo Kim, Department of Radiation Oncology, Ewha Womans University College of Medicine, Seoul 07985, South Korea
Author contributions: Kim K concepted and designed the study; Koo T and Park HJ reviewed and analyzed literature, and drafted the manuscript. All authors contributed to critical revision and editing, and approval of the final version.
Conflict-of-interest statement: No potential conflicts of interest. No financial support.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Kyubo Kim, MD, PhD, Associate Professor, Department of Radiation Oncology, Ewha Womans University College of Medicine, 1071 Anyangcheon-ro, Yangcheon-gu, Seoul 07985, South Korea. kyubokim.ro@gmail.com
Telephone: +82-2-2650-5334 Fax: +82-2-2654-0363
Received: February 21, 2019
Peer-review started: February 22, 2019
First decision: March 29, 2019
Revised: April 2, 2019
Accepted: April 18, 2019
Article in press: April 19, 2019
Published online: June 6, 2019
Processing time: 105 Days and 17.7 Hours
Abstract

Extrahepatic bile duct cancer (EBDC) is a rare malignancy that involves neoplastic changes extending from both hepatic ducts to the common bile duct. The treatment of choice is surgical resection, but the predominant pattern of initial treatment failure is locoregional recurrence. Accordingly, adjuvant radiotherapy has been administered after surgical resection based on these rationales. At this time, there is minimal evidence supporting adjuvant radiotherapy, because there have been no phase III trials evaluating its benefit. Relatively small retrospective studies have tried to compare outcomes associated with EBDC treated with or without radiotherapy. We aimed to review studies investigating adjuvant radiotherapy for resected EBDC. Because less than one-third of EBDC cases are amenable to curative resection at diagnosis, other locoregional treatment modalities need to be considered, including radiotherapy. The next aim of this review was to summarize reports of definitive radiotherapy for unresectable EBDC. Patients with advanced EBDC often experience biliary obstruction, which can lead to jaundice and progress to death. Biliary stent insertion is an important palliative procedure, but stents are prone to occlusion after subsequent ingrowth of the EBDC. Radiotherapy can be effective for maintaining the patency of inserted stents. We also reviewed the benefit of palliative radiotherapy combined with the biliary stent insertion. Lastly, we discuss the existing gaps in the evidence supporting radiotherapy in the management of EBDC.

Keywords: Extrahepatic bile duct cancer; Patterns of failure; Adjuvant radiotherapy; Definitive radiotherapy; Palliative radiotherapy; Biliary stent

Core tips: Radiotherapy has been administered for extrahepatic bile duct cancer patients in adjuvant, definitive, or palliative settings. The evidence in support of radiotherapy is derived from retrospective studies because there is a lack of randomized controlled trials. This review aimed to summarize contemporary series involving radiotherapy treatment for extrahepatic bile duct cancer. These data and findings were then used to propose strategies for generating robust evidence for or against the use of radiotherapy for this disease.