Phase II study of neoadjuvant anastrozole and concurrent radiotherapy for postmenopausal breast cancer patients.
BACKGROUNDS
The aim of this study was to assess the efficacy and safety of neoadjuvant anastrozole and radiation in postmenopausal breast cancer patients with hormone-receptor-positive tumors. In addition, we assessed the predictive factors for clinical and pathological response for concurrent anastrozole and radiotherapy.


METHODS
Patients with tumors 3 cm or larger were treated with neoadjuvant anastrozole for 24 weeks, and concurrent radiation was administered from 12 weeks after the start of anastrozole. Core biopsies were obtained at baseline and 12 weeks after the start of anastrozole. After completing neoadjuvant treatment, patients underwent definitive surgery. The primary endpoint was the overall objective response. In addition, we assessed the predictive factors for clinical and pathological response for concurrent anastrozole and radiotherapy. This trial is registered with the UMIN Clinical Trials Registry, no. UMIN000002266.


RESULTS
The overall objective response rate was 92 %. Toxicity during neoadjuvant therapy was acceptable, with no grade 3 toxicities. After surgery, grade 3 toxicities occurred in 2 of 25 patients (8 %).


CONCLUSIONS
Our preliminary data suggest that neoadjuvant anastrozole and radiation therapy in postmenopausal breast cancer patients with hormone-receptor-positive tumors has a high potential for clinical response.