Primary resistance to docetaxel-based chemotherapy in metastatic breast cancer patients correlates with a high frequency of BRCA1 mutations

Abstract

1079 Background: Docetaxel is a member of taxoid antineoplastic agents which are routinely used in the treatment of high-risk or metastatic breast cancer. A recent study has demonstrated that a low response rate to taxane-based neoadjuvant chemotherapy is associated with BRCA1 mutations. Therefore, we have analyzed the frequency of BRCA1 mutations in a population of metastatic, docetaxel-refractory patients. Methods: From a group of 175 metastatic breast cancer patients treated with docetaxel-based therapy 19 treatment-refractory patients were selected. DNA isolated from blood or paraffin-embedded tissues was screened for 3 founder mutations common (>80%) in Polish population. Additionally, the frequency of BRCA1 mutations was correlated with a particular phenotype of breast cancer cells. Results: BRCA1 mutations were found in 5/19 of patients (26.3%), and were only detected in 5 of 7 patients with triple-negative breast cancer (71%; p<0.002). Conclusions: Our study indicates that administration of taxane...