Results of the East Carolina Breast Center phase II trial of neoadjuvant metronomic chemotherapy in triple-negative breast cancer (NCT00542191).

Abstract

e11550 Background: Triple negative (ER negative, PR negative and HER 2 negative) breast cancers (TNBC) lack effective targeted therapy. We sought to determine the benefit of metronomic neoadjuvant chemotherapy utilizing doxorubicin with cyclophosphamide followed by paclitaxel with carboplatin in women with TNBC. Methods: Patients (pts) with TNBC>2cm were eligible (including locally advanced or inflammatory breast cancer). Pretreatment sentinel node biopsy (SLNB) was performed in patients with clinically N0 disease. Treatment consisted of weekly doxorubicin 24 mg/m2 + daily oral cyclophosphamide 60 mg/m2 x 12 weeks followed by weekly paclitaxel 80 mg/m2 + weekly carboplatin AUC 2 x 12 weeks. Granulocyte colony stimulating factor was added for ANC<= 1000. Pts received standard surgery and radiation therapy as indicated. The primary endpoint was pathologic response. Results: Between 2006 and 2011, 17 pts with infiltrating ductal TNBC were enrolled and 15 were analyzed. Age ranged from 25 to 83 (mean age 45yrs), primary tumor size ranged from 2cm to 7cm (mean 3.5cm). Three pts presented with inflammatory breast cancer, 4 had clinical N1 disease and 2 had clinical N0 disease that did not receive SLNB. Six pts underwent SLNB; 3 were pN0 and 3 were pN positive. Two pts came off study due to prolonged neutopenia. Three pts died during therapy-one of MI, one of PE and one had progressive pulmonary disease. No deaths were therapy related. Ten pts completed therapy. One experienced grade 3 (G3) thrombocytopenia, five patients had G4 neutropenia and one developed G3 neuropathy. Ten pts had a clinical complete response (cCR), four had a clinical partial response (cPR) and one progressed on therapy. The rate of pathologic complete response (pCR) was 46.6% (40% pCR, 6.6% CR with foci of DCIS). One patient had a 0.7cm focus of residual invasive carcinoma. Positive nodes were identified in 13.3%-one patient who progressed on therapy and one who experienced a cPR. Conclusions: Neoadjuvant metronomic chemotherapy with weekly doxorubicin plus daily oral cyclophosamide followed by weekly paclitaxel plus carboplatin revealed high rates of pCR with toxicities limited to marrow suppression.