A multicenter, randomized phase II study of neoadjuvant chemotherapy including trastuzumab with cyclophosphamide with docetaxel in patients with operable HER2-positive breast cancer (JBCRG-10 study).

Abstract

TPS105 Background: Japan Breast Cancer Research Group (JBCRG) is collaborating with Breast International Group (BIG) to develop new evidence for breast cancer treatments in Japan. Combination regimens of anthracyclines and taxanes have been widely used as preoperative systemic therapy (PST) in patients with operable breast cancer. However, we have several clinical questions related to PST: (1) additional effect of cyclophosphamide (CPA) to standard regimen (anthracycline and taxane) to identify preferred regimen for PST, (2) preferable order of anthracycline and taxane, (3) relation between the order of anthracycline and taxane and cardiac toxicity and (4) effect and safety of anthracycline-free regimen. To answer to these questions, we conduct this JBCRG 10 study. Methods: One hundred eighty HER2-positive breast cancer patients (T1C-3, N0-1, M0) are planned to be enrolled. Patients will receive the following treatment: (1)FEC-TCH group, 4 cycles of 5-fluorouracil (5-FU; 500 mg/m2, q3w) + epirubicin (EPI; 100 mg/m2, q3w) + CPA (500 mg/m2, q3w) (FEC regimen) followed by 4 cycles of docetaxel (75 mg/m2, q3w) + CPA (600 mg/m2, q3w) + trastuzumab (H; 2 mg/kg, weekly with loading 4 mg/kg or 6 mg/kg, q3w with loading 8 mg/kg) (TCH regimen); (2) TCH-FEC group, 4 cycles of TCH followed by 4 cycles of FEC and (3) TCH group, 6 cycles of TCH. The primary endpoint is pathological complete response (pCR) rate. Secondary endpoints include safety, cardiac toxicity rate, overall response rate, disease-free survival, overall survival, breast cancer conserving rate and nondissection rate of axillary lymph nodes. Translational research is also planned. In summary, JBCRG-10 will evaluate the efficacy and safety of FEC-TCH, TCH-FEC and TCH as PST in Japanese patients with operable HER2-positive breast cancer and will also answer to the question on regimen order and a power of anthracycline-free regimen. No significant financial relationships to disclose.