In real life, one-quarter of patients with hormone receptor-positive metastatic breast cancer receive chemotherapy as initial palliative therapy: a study of the Southeast Netherlands Breast Cancer Consortium

Background: The objective of this study wasto present initial systemic treatment choices and the outcome of hormone receptor-positive(HR+) metastaticbreastcancer.
Patients and methods: All the 815 consecutive patients diagnosed with metastatic breast cancer in 2007–2009 in eight participating hospitals were identified. From the 611 patients with HR+ disease, a total of 520 patients with HER2-negative(HER2−)breastcancerwereincluded.Initial palliativesystemictreatment wasregistered. Progression-free survival (PFS) and overall survival (OS) per initial palliative systemic therapy were obtained using the Kaplan–Meier method andcomparedusingthe log-rank test.
Results: From the total of 520 patients with HR+/HER2− metastatic breast cancer, 482 patients (93%) received any palliative systemic therapy. Patients that received initial chemotherapy (n=116) were significantly younger, had less comorbidity,had received more prioradjuvant systemic therapyand wereless likely tohave bonemetastasis onlycompared with patients that received initial endocrine therapy (n=366). Median PFS of initial palliative chemotherapy was 5.3 months [95% confidence interval (CI) 4.2–6.2] and of initial endocrine therapy 13.3 months (95% CI 11.3–15.5), with a median OS of 16.1 and 36.9 months, respectively. Initial chemotherapy was also associated with worse outcome in termsofPFSand OSafteradjustment forprognostic factors.
Conclusions: A high percentage of patients with HR+ disease received initial palliative chemotherapy, which was associated withworseoutcome,evenafteradjustment ofrelevant prognosticfactors.