Phase II trial of paclitaxel and cisplatin in women with advanced breast cancer: an active regimen with limiting neurotoxicity.

A phase II study of paclitaxel and cisplatin in patients with advanced breast cancer was performed to determine the objective response rate and make further observations about the toxicity of this regimen. Patients were required to have histologically proven adenocarcinoma of the breast with no more than one chemotherapeutic treatment for advanced disease. Treatment consisted of paclitaxel 200 mg/m2 administered as a 24-hour intravenous (i.v.) infusion followed by cisplatin 75 mg/m2 i.v. Patients received granulocyte colony-stimulating factor (G-CSF) 5 micrograms/kg subcutaneously on day 3 until WBC recovery. Cycles were repeated every 21 days. Patients continued to receive therapy until disease progression or unacceptable toxicity. Forty-four patients entered the trial. Forty-two patients were assessable for response. Nineteen patients (43%) had no prior chemotherapy and 41 had no chemotherapy for metastatic disease. The median number of cycles administered per patient was five (range, one to seven). There were five complete responses (CRs) (11.9%) and 17 partial responses (PRs) (40.5%), with an overall response rate of 52.4% (95% confidence interval [CI], 36.4% to 68.0%). Nine patients had stage III disease. The response rate for this group was 66.7% (95% CI, 33.0% to 92.5%), with three CRs and three PRs. Among 35 patients with stage IV disease, there were two CRs and 14 PRs, with an overall response rate of 48.5% (95% CI, 30.8% to 66.5%). Overall, the median response duration was 10.6 months. Thirty patients (68%) developed transient grade 4 neutropenia. Cumulative neuropathy was the major dose-limiting toxicity. After five cycles of chemotherapy, 96% of patients had at least grade 1 neurotoxicity and 52% had at least grade 2 neurotoxicity. One patient had a toxic death after cycle 1 of therapy. The combination of paclitaxel and cisplatin as first-line chemotherapy for women with advanced breast cancer is an active regimen. However, the cumulative neurotoxicity was significant and dose-limiting in the majority of patients.