Neoadjuvant endocrine treatment in breast cancer: analysis of daily practice in large cancer center to facilitate decision making

BackgroundTo examine outcomes of neoadjuvant endocrine therapy in daily practice to inform decision making.MethodsWe retrospectively selected 204 patients who received neoadjuvant endocrine therapy with T2 (≥30 mm) or T3 tumors, examining subsequent breast-sparing surgery and long-term outcomes.ResultsNeoadjuvant endocrine therapy was administered for 7.3 months (median) and breast-sparing surgery was achievable in 53% of patients. Smaller initial tumor size and modified version of the Scarff–Bloom and Richardson grades 1 to 2 were associated with breast-sparing surgery. Disease progression during treatment was 6.9%; actuarial risk of local relapse was 3% at 5 years and 15% at 10 years. Five- and 10-year metastasis relapse-free survival was 78% and 63%, respectively. Grade 3, negative progesterone receptors, and absence or slow response to neoadjuvant therapy were associated prognostic factors.ConclusionThese daily practice data provide important information about feasibility, efficacy, and long-term results of neoadjuvant endocrine therapy and can be used to inform patients for decision making between mastectomy and endocrine induction therapy.