Systemic therapy in younger and elderly patients with advanced biliary cancer: sub-analysis of ABC-02 and twelve other prospective trials

Background: Outcomes in younger (<40 years) and elderly (≥70 years) patients with advanced biliary cancer (ABC) receiving palliative chemotherapy are unclear. This study assessed outcomes in those receiving monotherapy or combination therapy in thirteen prospective systemic-therapy trials. Methods: Multivariable analysis explored the impact of therapy on progression-free (PFS) and overall survival (OS) in two separate age cohort groups: <70 years and ≥70 years, and <40 years and ≥40 years. Results: Overall, 1163 patients were recruited (Jan 1997-Dec 2013). Median age of entire cohort: 63 years (range 23-85); 36 (3%) were <40, 260 (22%); ≥70. Combination therapy was platinum-based in nine studies. Among patients <40 and ≥70 years, 23 (64%) and 182 (70%) received combination therapy, respectively. Median follow-up was 42 months (95%-CI 37-51). Median PFS for patients <40 and ≥40 years was 3.5 and 5.9 months (P=0.12), and OS was 10.8 and 9.7 months, respectively (P=0.55). Median PFS for those <70 and ≥70 years was 6.0 and 5.0 months (P=0.53), and OS was 10.2 and 8.8 months, respectively (P=0.08). For the entire cohort, PFS and OS were significantly better in those receiving combination therapy: Hazard Ratio [HR]-0.66, 95%-CI 0.58-0.76, P<0.0001 and HR-0.72, 95%-CI 0.63-0.82, P<0.0001, respectively; and in patients ≥70 years: HR-0.54 (95%-CI 0.38-0.77, P=0.001) and HR-0.60 (95%-CI 0.43-0.85, P=0.004), respectively. There was no evidence of interaction between age and treatment for PFS (P=0.58, P=0.66) or OS (P=0.18, P=0.75). Conclusions: In ABC, younger patients are rare, and survival in elderly patients in receipt of systemic therapy for advanced disease, whether monotherapy or combination therapy, is similar to that of non-elderly patients, therefore age alone should not influence decisions regarding treatment.