Phase II trial of weekly nab-paclitaxel and carboplatin treatment with or without trastuzumab as nonanthracycline neoadjuvant chemotherapy for locally advanced breast cancer.

backgroundNeoadjuvant chemotherapy has become standard treatment for women with locally advanced breast cancer. The aim of this study was to compare the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) versus paclitaxel combined with carboplatin.

methodsThirty patients were treated with neoadjuvant nab-paclitaxel (125 mg/m(2), days 1, 8, and 15) and carboplatin (area under the curve =2; days 1, 8, and 15) every 21 days for four cycles. Ninety matched patients received paclitaxel (80 mg/m(2), days 1, 8, and 15) and carboplatin every 21 days for four cycles. Weekly trastuzumab is recommended for overexpression of human epidermal receptor-2. The primary endpoint was pathologic complete response (defined as ypT0/is ypN0). Matching was conducted according to six variables: body mass index, clinical tumor stage, clinical lymph node status, estrogen receptor status, HER2 status, and trastuzumab receiving rate.

resultsNinety percent of patients in the nab-paclitaxel group and 80% of patients in the paclitaxel group experienced a clinical objective response (complete response or partial response; P=0.450). Eight patients in the nab-paclitaxel group and 23 patients in the paclitaxel group had a pathologic complete response in the breast and axillary nodes (26.7% versus 25.6%; P=0.904). Nab-paclitaxel showed a beneficial effective trend on clinical tumor stage II (36.8% versus 15.8%; P=0.051). When trastuzumab was added to nab-paclitaxel, the pathologic complete response rate was not significantly improved more than with trastuzumab and paclitaxel (43.6% versus 39.6%; P=0.769). Carboplatin plus nab-paclitaxel or paclitaxel had similarly low pathologic complete response rates (7.7% versus 10.5%) for the luminal molecular subtype. One (50%) triple-negative patient achieved a pathologic complete response. The nab-paclitaxel regimen caused more grade 4 neutropenia than the paclitaxel regimen (56.7% versus 21.1%; P<0.001).

conclusionOur study shows that weekly nab-paclitaxel and carboplatin with or without trastuzumab resulted in a pathologic complete response rate that was not superior to the matched cohorts. Future, larger trials are needed to validate that nab-paclitaxel is beneficial for clinical tumor stage II and the triple-negative subgroup.