ABSTRACT
Background. - Trastuzumab is known as an active agent in HER2/neu overexpressing advanced breast cancer. In the prospective study we investigated efficacy, safety and toxicity of trastuzumab and paclitaxel in advanced breast cancer progressing on previous therapy. Patients and methods. - Seventeen patients with histologically confirmed disease were accrued. Inclusion criteria were as follows: Karnofsky performance status >/= 60 %, age < 75, pretreatment with at least two regimens; HER2/neu by immunohistochemistry 3+ or 2+, adequate organ function. Trastuzumab was given 4 mg/kg i.v. as a loading dose followed by 2mg/kg i.v. weekly. Paclitaxel was given 80 mg/m2 i.v. weekly. Both drugs were given until disease progression or unacceptable toxicity. We assessed the response rate (RR), the time to progression (TTP), the overall survival (OS) and toxicity. Results. RR in the intent to treat population was 59 % (10 out of 17), including 2 complete responses. In the median follow up of 4,3 years median TTP was 9 month and median OS 23 month. In total 710 cycles including 528 full dose cycles of trastuzumab and paclitaxel were administered. One patient developed hypersensitivity reaction after the first trastuzumab infusion and discontinued from study. Trastuzumab infusion related pyretic reaction was observed in 6 patients. Left ventricular ejection fraction decline occurred in 2 patients (grade 2 and grade 3). Five patients experienced grade 3 neuropathy. Hematological toxicity was very modest: 1 episode of grade 4 neutropenia and grade 3 anemia. Other grade 3/4 toxicity: 4 episodes of grade 3 infection without neutropenia, grade 3 elevation of liver function tests in 1 patient, 1 episode of grade 3 hyperglycemia, and 1 episode of grade 3 weight gain. Other grade 3 or 4 toxicity was not detected. Conclusion. - Trastuzumab and paclitaxel have shown activity and good tolerability in HER-2/neu overexpressing advanced breast cancer patients.
