Multicentre match-paired analysis of advanced biliary cancer long-term survivors: The BILONG study

Background: Advanced biliary cancers (ABC) are aggressive malignancies with a median overall survival (mOS) <12 months when treated with first-line chemotherapy. Nevertheless, a subset of patients experiencing longer survival has been described in the updated analysis of ABC-02 trial. We aimed to provide a real-world description of ABC long-term survivors (LS), identifying which factors impact on survival.

Methods: Patients diagnosed with ABC at three Institutions between 2002 and 2019, and who survived ≥18 months, were retrospectively identified. We compared them with a control cohort (C) with a mOS <18 months, matched on age, gender, ECOG PS, disease status, primary tumor site, prior surgery, and treatment modality. Their clinical features, treatments, and outcome were analyzed.

Results: A total of 78 patients was included, 39 in each group. Both LS and C cohorts had superimposable baseline characteristics, without significant differences. mOS was 29 (95%CI 24.6-33.5) and 9 months (95%CI 6.6-12.9) in the two groups, respectively. After performing a logistic regression analysis, three factors were significantly associated with long-term outcome: low neutrophil-to-lymphocyte ratio (NLR < 3) (Odds Ratio [OR] 0.38), achievement of objective response to treatment (OR 0.16), and the number of lines received (OR 0.29).

Conclusions: We described a considerable subset of ABC experiencing long-term survival with conventional chemotherapy in a real-world scenario. Beyond clinical factors, we identified low NLR as a prognostic determinant that may allow for a more accurate selection of long survivors. While waiting for a deeper molecular characterization of this subgroup, we propose NLR as a stratification factor for daily practice and clinical trials.