Real-world data from patients treated with chemotherapy for biliary tract cancer: insights from a prognostic model. ^☆

Cisplatin-gemcitabine (CisGem) chemotherapy with immunotherapy is the standard of care first-line treatment for advanced biliary tract cancer (BTC). However, some relevant clinical questions cannot be answered through randomised clinical trials due to feasibility issues: the role of maintenance chemotherapy, the equivalence of the gemcitabine-oxaliplatin (GEMOX) regimen, the preferred treatment of patients with Performance Status (PS) 2. We thus built a large multicentre database, and created a prognostic model to provide corrected comparisons of outcomes of patients treated in the real-world setting.

Retrospective analysis of patients treated at 15 European institutions with first-line chemotherapy for advanced BTC. We built a prognostic model of patients treated with CisGem, with internal validation, and used this model to provide corrected comparisons of different treatments.

1947 patients were included, with 1022 treated with CisGem. Parameters included in the prognostic model were tumour differentiation, PS, extent of the disease (locally-advanced vs metastatic), albumin and CA19.9. Maintenance chemotherapy did not impact PFS or OS (n=79, median 17.0 with vs 23.7 months without, HR: 1.63 (95% Confidence Interval (CI) 0.95-1.74); p: 0.078). GEMOX was inferior to CisGem (n=1471, median 9.9 vs 11.4 months, Hazard Ratio for OS = 1.18, 95% CI: 1.00-1.41; p=0.049). CisGem was superior to gemcitabine in patients with PS 2 (n=233, median OS of 6.8 vs 3.6 months; HR:1.70 (95% CI: 1.30, 2.22); p:<0.001)).

This large multicentre database allowed for the development of a prognostic model that provides useful data on clinically-relevant unanswered questions. The cessation of chemotherapy after 8 cycles is recommended; CisGem is endorsed as the main backbone chemotherapy over GEMOX; CisGem should be preferred over single-agent gemcitabine in patients with PS2.

This study tries to address some unresolved questioned in biliary tract cancer treatment. We confirmed that the Cisplatine-gemcitabine seems to be a better chemotherapy backbone as compared with GEMOX. We suggest that maintenance chemotherapy does not improve overall survival, and that cisplatine-gemcitabine should be preferred to single-agent gemcitabine in patient with a performance status of 2.