Chemotherapy for advanced gallbladder cancer (GBC): A systematic review and meta-analysis

Background: The benefit from chemotherapy, specifically for patients with gallbladder cancer (GBC), has been poorly explored since GBC is mostly studied jointly with other biliary tract cancers (BTC). Methods: Eligible studies reporting outcome of palliative systemic chemotherapy for advanced GBC were identified through MEDLINE, cross-referencing and conferences (PROSPERO-CRD42019155745). Meta-analysis of proportions and calculation of pooled weighted means were performed. Results: 58 eligible studies (n = 1,986 patients); cisplatin/gemcitabine (33 % of patients), gemcitabine/oxaliplatin (14 %) or gemcitabine monotherapy (9%). Estimated pooled overall radiological response rate(ORR), and pooled weighted mean progression-free (PFS) and overall survivals (OS) were 23.2 % (95 %-CI 20.0-26.5) (I2: 52.5 % (p < 0.001)), 4.8 months (95 %-CI 4.3-5.2) and 8.3 months (95 %CI 7.6-8.9), respectively. Patients with non-GBC BTCs achieved a lower ORR than GBC [odds ratio 0.65 (95 % CI, 0.50- 0.84)]. Conclusions: GBC benefit from chemotherapy differs from other BTCs, with shorter PFS/OS despite higher ORR; new treatment options are urgently required for management of advanced GBC.