Adjuvant Chemoradiotherapy is Associated with Improved Survival for Patients with Resected Gallbladder Carcinoma: A Systematic Review and Meta-analysis

Background: The impact of adjuvant radiotherapy (ART) on survival from gallbladder carcinoma (GBC) remains underexplored, with conflicting results reported. A systematic review and meta-analysis was performed to clarify the impact of ART in GBC. Methods: A systematic literature search of several databases was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, from inception to August 2016. Studies that reported survival outcomes for patients with or without ART after curative surgery were included. Results: All the inclusion criteria was met by 14 retrospective studies including 9364 analyzable patients, but most of the studies had a moderate risk of bias. Generally, the ART group had more patients with unfavorable characteristics than the group that had surgery alone. Nevertheless, the pooled results showed that ART significantly reduced the risk of death (hazard ratio [HR], 0.54; 95% confidence interval [CI] 0.44–0.67; p < 0.001) and recurrence (HR 0.61; 95% CI 0.38–0.98; p = 0.04) of GBC compared with surgery alone. Exploratory analyses demonstrated a survival benefit from ART for a subgroup of patients with lymph node-positive diseases (HR 0.61; p < 0.001) and R1 resections (HR 0.55; p < 0.001), but not for patients with lymph node-negative disease (HR 1.06; p = 0.78). No evidence of publication bias was found (p = 0.663). Conclusions: This study is the first meta-analysis to evaluate the role of ART and to provide supporting evidence that ART may offer survival benefits, especially for high-risk patients. However, further confirmation with a randomized prospective study is needed to clarify the subgroup of GBC patients who would benefit most from ART.