[Phase II clinical trial of neoadjuvant therapy with carboplatin plus paclitaxel for locally advanced triple-negative breast cancer].

OBJECTIVE: To evaluate the efficacy, safety and survival of combination of carboplatin plus paclitaxel as neoadjuvant chemotherapy (NACT) for patients with locally advanced triple-negative breast cancer (TNBC), and explore an optimal regimen for TNBC.

METHODS: Patients with core needle biopsy confirmed pathological diagnosis of IIA ∼ IIIC invasive breast cancer, negative for estrogen and progesterone receptors and HER2 by immunohistochemistry, and with indication for NACT were eligible in this study. The biopsy tumor tissues were tested for CK5/6, CK14, EGFR and Ki67. The patients received paclitaxel 175 mg/m(2) on day 1, carboplatin at an area under the curve 5 mg×min/ml on day 2 of every 21 days. The clinical response was evaluated every 2 cycles according to Standard RECIST 1.0 criteria and surgery was done after four to six cycles. Pathological complete remission (pCR) was defined if absence of invasive tumor in the breast and axillary lymph nodes samples or residual carcinoma in situ only.

RESULTS: Overall, thirty-one patients were enrolled from January 2008 to November 2010. The median age was 51 years and 83.9% of the patients were diagnosed as stage IIB to IIIC diseases. 30 Patients completed chemotherapy as planed while one patient changed regimen due to paclitaxel allergy. Twenty-eight patients could be evaluated for clinical efficacy, of which CR, PR, SD, PD were achieved in 4, 20, 3 and 1 women, respectively. The objective response rate was 85.7%. The expression rate of CK5/6, CK14 and EGFR were 88.9% (24/27), 59.3% (16/27) and 63% (17/27), respectively. Among 27 patients who received modified radical mastectomy or breast-conserving surgery, 11 patients obtained pCR, with a pCR rate of 40.7% (95%CI 22.2% - 59.3%). Five of six CK5/6- and CK14-positive patients achieved pCR. All the 31 patients could be evaluated for toxicity according to the NCI-CTC v3.0 criteria. The major toxicities were neutropenia (93.5%), vomiting (45.2%) and ALT/AST increase (32.3%), and grade 3-4 toxicities accounted for 74.2%, 3.2%, 0, respectively. Until December 2011, at a median follow-up of 28.9 months (range 5 - 47.9), eight patients developed recurrence including 5 patients died. Among 11 patients with pCR, one suffered from lung metastasis at 45 months after diagnosis and survived with tumor until now. The other ten were alive and disease free. The 3-year DFS and OS were 62% and 74.7%, respectively.

CONCLUSIONS: As a neoadjuvant treatment for triple-negative breast cancer, carboplatin plus paclitaxel regimen achieves notable higher objective response rate and pCR rate compared with the anthracycline plus paclitaxel regimen reported in the literature, and is well tolerable. It is an optimized regimen for TNBC.