A systematic review of the effectiveness of adjuvant therapy for patients with gallbladder cancer.

Background: Equipoise exists regarding the benefit of adjuvant therapy (AT) in patients with gallbladder cancer (GBC). The aim of this study was to critically review the available evidence for the effectiveness of AT in patients with GBC following surgery with curative intent.
Methods: A systematic review was performed. Relevant studies were identified from Trip Database, BIREME-BVS, SciELO, Cochrane Central Register, WoS, MEDLINE, EMBASE and SCOPUS. Adjuvant therapies considered included chemotherapy, chemoradiotherapy, and radiotherapy. The primary outcome was overall survival (OS). Subgorup analysis of patients with positive lymph node disease (PLND), positive surgical margin (PSM), or advanced stage (AS) were performed.
Results: 748 related articles were identified; 27 met the selection criteria (3 systematic reviews and 24 observational studies). Evidence provided was moderate, poor and very poor for chemotherapy, chemoradiotherapy, and radiotherapy. Existing evidence is not robust, but suggests certain benefits with AT in improving OS, especially in patients with PLND, PSM and AS.
Conclusion: Results do not provide strong evidence that AT is effective in patients who undergo resection for GBC. Subgroups of PLND and PSM may have a survival advantage. Future studies with appropriate internal validity and adequate number of patients are required to better answer this question.
(Copyright © 2019 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.)