Saeko Teraoka1, Eiichi Sato2, Kazutaka Narui3, Akimitsu Yamada4, Tomoyuki Fujita5, Kimito Yamada1, Mari Oba6, Takashi Ishikawa7. 1. Department of Breast Oncology and Surgery, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan. 2. Department of Pathology, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan. 3. Department of Breast Surgery, Yokohama City University Medical Center, Yokohama-shi, Kanagawa, Japan. 4. Department of Breast Surgery, Chigasaki Medical Hospital, Chigasaki-shi, Kanagawa, Japan. 5. Department of Breast and Thyroid Surgery, Tokyo Medical University Ibaraki Medical Center, Inashikigun, Ibaraki, Japan. 6. Department of Medical Statistics, Faculty of Medicine, Toho University, Ota-ku, Tokyo, Japan. 7. Department of Breast Oncology and Surgery, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan. Electronic address: tishik55@gmail.com.
Abstract
BACKGROUND: A subgroup of triple-negative breast cancer (TNBC) shows impaired BRCA1 function owing to causes other than mutation, which is called "BRCAness." DNA-damaging agents are known to have more efficacy in BRCA1-mutant tumors than mitotic poisons. We conducted a prospective single-arm clinical trial of neoadjuvant chemotherapy (NAC) using an anthracycline-based regimen without taxanes for BRCAness TNBCs. MATERIALS AND METHODS: BRCAness was examined using the multiplex ligation-dependent probe amplification (MLPA) method in TNBC cases. For BRCAness cases, NAC was performed with anthracycline-based regimens without additional taxanes. RESULTS: A total of 30 patients with TNBC were enrolled. MLPA was successfully performed in 25 patients. Eighteen patients (72%) showed BRCAness. Twenty-three patients received NAC as per the protocol. On analysis, the clinical response rate (complete response plus partial response) was 76.4%, and the pathological complete response rate was 35.3%. CONCLUSIONS: The interim analysis revealed that the pathological complete response rate was lower than estimated. Therefore, BRCAness by MLPA was not sufficient to predict the therapeutic response to anthracycline-based regimens in TNBC.
BACKGROUND: A subgroup of triple-negative breast cancer (TNBC) shows impaired BRCA1 function owing to causes other than mutation, which is called "BRCAness." DNA-damaging agents are known to have more efficacy in BRCA1-mutant tumors than mitotic poisons. We conducted a prospective single-arm clinical trial of neoadjuvant chemotherapy (NAC) using an anthracycline-based regimen without taxanes for BRCAness TNBCs. MATERIALS AND METHODS: BRCAness was examined using the multiplex ligation-dependent probe amplification (MLPA) method in TNBC cases. For BRCAness cases, NAC was performed with anthracycline-based regimens without additional taxanes. RESULTS: A total of 30 patients with TNBC were enrolled. MLPA was successfully performed in 25 patients. Eighteen patients (72%) showed BRCAness. Twenty-three patients received NAC as per the protocol. On analysis, the clinical response rate (complete response plus partial response) was 76.4%, and the pathological complete response rate was 35.3%. CONCLUSIONS: The interim analysis revealed that the pathological complete response rate was lower than estimated. Therefore, BRCAness by MLPA was not sufficient to predict the therapeutic response to anthracycline-based regimens in TNBC.