Preoperative concurrent endocrine therapy with chemotherapy in luminal B-like breast cancer

Purpose Luminal B-like breast cancer is sensitive to both chemotherapy and endocrine therapy. We aimed to assess the safety and efficacy of concomitant chemotherapy and endocrine therapy compared with chemotherapy alone in the preoperative setting in luminal B-like breast cancer. Methods This two-arm randomized clinical trial enrolled patients with luminal B-like human epithelial growth factor 2-negative breast cancer, who were randomly assigned at a 1:1 ratio to receive preoperative chemotherapy alone or preoperative endocrine therapy concurrent with chemotherapy for 24 weeks before surgery. The primary endpoint was the pathological complete response (pCR) rate. The secondary endpoints included the clinical response rate, toxicity, and health-related quality of life (HRQOL). Results Overall, 70 patients were randomly assigned to the chemotherapy and chemo-endocrine therapy groups. The pCR rates were 9.7% and 3.0% ( P = 0.319), and the clinical complete response rates were 5.9% and 5.6% ( P = 0.745) in the chemotherapy and chemo-endocrine therapy groups, respectively. There were no clear differences in treatment-related adverse events or HRQOL between the two groups. Conclusions In patients with luminal B-like breast cancer, the pCR, clinical response rate, toxicity, and HRQOL with the concomitant administration of endocrine therapy and chemotherapy were not superior to chemotherapy alone in the preoperative setting.