Cisplatin and gemcitabine for advanced biliary tract cancer: a meta-analysis of two randomised trials

Background: Two recent studies (ABC-02 [UK] and BT22 [Japan]) have demonstrated the superiority of cisplatin and gemcitabine (CisGem) chemotherapy over gemcitabine (Gem) alone for patients with pathologically proven advanced biliary tract cancer (BTC: cholangiocarcinoma, gallbladder and ampullary cancers). This pre-planned analysis evaluates the efficacy of CisGem with increased statistical power.

Patients and methods: We carried out a meta-analysis of individual patient-level data of these studies to establish the effect of CisGem versus Gem on progression-free survival (PFS), overall survival (OS) and carried out exploratory subgroup analyses.

Results: CisGem demonstrates a significant improvement in PFS [hazard ratio (HR)=0.64, 95% confidence interval (CI) 0.53-0.76, P<0.001] and OS (HR=0.65, 95% CI 0.54-0.78, P<0.001) over Gem. This effect is most marked among patients with good performance status (PS 0-1): HR for PFS is 0.61 (95% CI 0.51-0.74), P<0.001 and OS HR=0.64 (95% CI 0.53-0.77), P<0.001. CisGem resulted in improved PFS and OS for intra- and extra-hepatic cholangiocarcinomas and gallbladder cancer. The treatment effect between UK and Japanese patients was consistent with respect to OS (HR=0.65, 95% CI 0.53-0.79 and 0.65, 95% CI 0.42-1.03, respectively); with similar OS in the combination arms (median 11.7 and 11.1 months, respectively). Subgroups least likely to benefit included patients with ampullary tumours and poor performance status (PS2).

Conclusions: CisGem is the standard of care for the first-line treatment of good-PS patients with advanced BTC regardless of ethnicity. Future studies should aim to enhance the effectiveness of this regimen in the first-line setting, establish the role of subsequent (second-line) therapy and assess the role of rationally developed molecular-targeted therapies.