Systemic therapy in elderly patients with advanced biliary tract cancer, sub-analysis of ABC-02 and ten other prospective studies

Background: Outcomes in elderly patients (pts), with advanced biliary tract cancer (ABTC) receiving palliative chemotherapy are unclear. The aim of this study was to assess the outcome of monotherapy vs combination therapy in elderly pts with ABTC in ABC-02, and 10 other prospective studies of systemic therapy. Methods: Multivariable analysis was employed to explore impact of therapy on progression-free (PFS) and overall survival (OS) in 2 age cohorts; non-elderly ( <70 yrs) vs elderly ( ≥ 70 yrs). Results: Overall, 1163 pts were recruited from Jan 97-Dec 13. Median age of entire cohort was 63 yrs (range 23-85); 260 (22%) were ≥ 70 yrs, 18 (2%) were ≥ 80 yrs. In pts ≥ 70 yrs; 208 had ECOG PS 0-1, 129; male and 174; metastatic disease. Combination therapy was platinum-based in 9 studies. Among the 260 pts ≥ 70 yrs, 182 (70%) received combination therapy. Baseline characteristics/therapy received was balanced in both age cohorts. Median follow-up time for all pts was 42 months (95% CI 37-51). Median PFS for those <70 yrs and ≥ 70 yrs was 6.0 (95% CI 5.5-6.4) and 5.0 months (95% CI 4.2-6.4) respectively. Median OS for pts <70 yrs and ≥ 70 yrs was 10.2 (95% CI 9.6-11.1) and 8.8 months (95% CI 7.9-9.6) respectively. For the entire cohort, the PFS and OS were significantly better in those pts receiving combination therapy: 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 group ≥ 70 yrs: HR 0.54 (95% CI 0.38-0.77, P = 0.001) and HR 0.6 (95% CI 0.43-0.85, P = 0.004) respectively. In pts <70 yrs, stage (locally advanced vs metastatic) and ECOG PS were prognostic for PFS (P <0.001 and P = 0.04 respectively) and OS (P <0.001 and P = 0.001 respectively) and in pts ≥ 70 yrs, they were prognostic for OS (P = 0.03 and P = 0.02 respectively). There was no evidence of interaction between age ( <70 yrs and ≥ 70 yrs) and treatment (monotherapy and combination therapy) for PFS (P = 0.66) or OS (P = 0.75). Conclusions: In ABTC, PFS and OS in elderly pts receiving palliative chemotherapy (monotherapy or combination therapy) are comparable with that of non-elderly pts, therefore age in isolation should not influence treatment decisions. Clinical trial participation among elderly pts with ABTC is appropriate.