Adjuvant taxane-based chemotherapy treatment in older patients with early breast cancer: A pooled analysis of five phase III trials from the Hellenic Oncology Research Group.

Introduction: The use of taxanes in the adjuvant setting of early breast cancer (BC) confers survival benefits, however, their role in older patients merits further study. This retrospective pooled analysis of randomized controlled trials conducted by the Hellenic Oncology Research Group (HORG) aims to assess the efficacy and safety of taxane-based adjuvant chemotherapy in older women with BC.

Materials And Methods: Five phase III trials containing a taxane, conducted by HORG between 1995 and 2013, were included in a patient-data pooled analysis. The primary endpoint was disease-free survival (DFS) at three years, whereas secondary outcomes included overall survival (OS) at five years and toxicity.

Results: A total of 3,026 randomized patients, of whom 701 (23 %) were ≥ 65 years old (median age 69 years; range 65-80), were included in the analysis. No statistically significant heterogeneity in survival was observed between older and younger patients. Within the cohort of older patients, taxane-based regimens were superior to 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) regimen in terms of three-year DFS (92.02 % vs 77.17 %; p < 0.001) and five-year OS (94.38 % vs 72.64 %; p < 0.001), respectively. A higher number of older patients discontinued treatment compared to younger patients (5.7 % vs 2.9 %; p < 0.001), mainly due to toxicity (3.4 % vs 1.8 %; p = 0.01). The incidence of grade 3-4 neutropenia (35.4 % vs 29.8 %; p = 0.006) and thrombocytopenia (0.8 % vs 0.3 %; p = 0.049) was higher for patients aged ≥65 years compared to those aged <65 years; however, there was no difference in terms of febrile neutropenia and non-hematologic toxicity.

Discussion: Taxane-based adjuvant chemotherapy offers significant survival benefits in older patients with BC, similar to younger patients, yet with increased toxicity.