Extreme response to nab-paclitaxel and trastuzumab treatment in two patients with locally advanced or recurrent breast cancer

Abstract

Nab-paclitaxel is a novel nanoparticle, albumin-bound paclitaxel that is free of solvents. The absence of solvents allows nab-paclitaxel to be administered without the premedication used routinely for the prevention of hypersensitivity reaction. In addition, the albumin-bound nanoparticle was designed to preferentially deliver paclitaxel to tumors by biologically interacting with albumin receptors that mediate drug transport. We report two cases of locally advanced or recurrent breast cancer patients with extreme response to nab-paclitaxel and trastuzumab treatment. One case is a 38-year-old woman who developed locally recurrent breast cancer, in her right chest wall; it was refractory to anthracycline and taxane treatment, and she had hypersensitivity to alcohol. After 6 cycles of chemotherapy with nab-paclitaxel (260 mg/m2) and trastuzumab every 3 weeks (q3w), the response to the treatment was clinical complete response (CR) according to the Response Evaluation Criteria in Solid Tumors (RECIST) guidelines, all recurrence masses seemed to have disappeared clinically, and pathological findings revealed that a slightly invasive lesion, measuring only 9 × 2 mm, remained. The second case is a 41-year-old woman with locally advanced breast cancer, whose tumor did not respond to chemotherapy with fluorouracil (500 mg/m2), epirubicin (100 mg/m2), and cyclophosphamide (500 mg/m2). She had active bronchial asthma. As second-line treatment, we used q3w nab-paclitaxel and trastuzumab. In spite of dose reduction for grade 2 liver dysfunction, she achieved pathological CR. Because our findings demonstrated remarkable efficacy and a good safety profile, we consider nab-paclitaxel with trastuzumab treatment to be one of the promising choices for locally advanced or recurrent breast cancer patients.