Pathologic complete response after neoadjuvant paclitaxel and carboplatin chemotherapy for stage II-III breast cancer: A community cancer center experience.

Abstract

43 Background: To evaluate the efficacy and safety of neoadjuvant carboplatin and weekly paclitaxel in locally advanced breast cancer. Methods: In a retrospective study, 15 patients receiving neoadjuvant chemotherapy with carboplatin and paclitaxel from 2008 to 2013 were identified with breast cancer stages IIA to IIIB. Patients received carboplatin at 6 times the area under the curve (AUC 6) every 4 weeks and paclitaxel 80 mg/m2 weekly for 16 weeks. Weekly trastuzumab was added for human epidermal growth factor receptor 2 (HER2) positive status. The primary endpoint was pathologic complete response (pCR) rate, defined as the absence of invasive cancer in breast and axillary lymph nodes. Partial response was defined as downstaging from clinical to pathologic stage. Results: 15 patients were identified. Median age was 57 years (range, 33 to 80 years). 6 women were African American, 3 Hispanic, 2 Asian and 3 Caucasian. 4 patients had stage IIIB disease, 5 had stage IIIA, 5 had Stage IIB and one had stage IIA. 2 patients had inflammatory cancer. 8 patients underwent modified radical mastectomy, 2 bilateral mastectomy and 4 lumpectomy. The tumor was estrogen receptor positive (ER+) in 8 patients, triple negative in 7 patients and HER2 positive in 2 patients. There were two episodes of febrile neutropenia and one death from sepsis. There was one episode of grade 4 thrombocytopenia requiring dose reduction of carboplatin to AUC 4. There were two instances of grade 3 peripheral neuropathy. One of these patients received a dose reduction of paclitaxel to 70 mg/m2. 10 patients received additional dose dense chemotherapy with doxorubicin and cyclophosphamide. Overall, the pCR rate was 0. Partial response was seen in 9 patients (60%). 14 patients received postoperative radiation; one patient declined radiation therapy. Conclusions: In cooperative group trials, neoadjuvant carboplatin and paclitaxel has been shown to achieve high pCR rates in patients with triple negative and HER2 positive breast cancer without exposure to an anthracycline. In our ethnically diverse patient population at a community cancer center, no pathologic complete responses were seen.