RESUMO
Pegylated liposomal doxorubicin (PLD) has the advantage of delivering active anthracycline directly to the tumor site, while exposing the patient to a lesser degree of doxorubicin-associated toxicities. Recently, a regimen in which paclitaxel is infused weekly over 1 h produced substantial antitumor activity with little myelosuppression. We designed a phase II trial to study the efficacy and toxicity of 10 mg/m(2) PLD on Days 1, 8 and 15, plus 70 mg/m(2) paclitaxel weekly in patients with untreated metastatic breast cancer and a high risk of cardiotoxicity. The study included 35 patients, with 31 (88.5%) evaluable for efficacy and 35 (100%) for toxicity. A total of 28 patients (80%) had two or more sites of disease. Overall, 4 complete and 16 partial responses were noted with an overall response rate of 64.5%, with 6 cases of stable and 5 cases of progressive disease. Toxicity was found to be manageable in that the only grade 3-4 side effects recorded were palmar-plantar erythrodysesthesia, 8.5%; mucositis, 2.8%; leucopenia, 12.5%; anemia, 2.8% and AST/ALT, 2.8%. No cardiotoxicity was observed. In conclusion, weekly PLD plus paclitaxel appears to be a well-tolerated and effective approach for metastatic breast cancer patients with a high risk of cardiotoxicity.
RESUMO
AIMS AND BACKGROUND: Patients with metastatic breast cancer previously treated with anthracyclines for advanced disease are usually refractory to any further treatment with anthracyclines and have a poor prognosis. Therefore, new drugs or new combinations of drugs are needed. One approach has been to focus on the type of chemotherapy with low toxicity that preserves quality of life during treatment, such as weekly drug administration. STUDY DESIGN: We designed a dose-finding study to determine the maximum tolerated dose of gemcitabine plus docetaxel, given on a weekly schedule in metastatic breast cancer previously treated with anthracyclines. Three escalating doses of gemcitabine (900, 1000 and 1100 mg/m2) on days 1 and 8 in combination with a fixed dose of docetaxel, 35 mg/m2 on days 1 and 8 were planned. Dose-limiting toxicity included grade > 3 hematologic toxicity, grade > 2 stomatitis, asthenia, diarrhea or organ-specific toxicity (except alopecia). Dose escalation was stopped if 1 out of 3 patients at any dose level experienced dose-limiting toxicity. RESULTS: Nine patients received a mean of 5.1 (range, 1-9) cycles. Gastrointestinal and leukopenia were the main dose-limiting toxicity. No patient experienced dose-limiting toxicity at dose level 1; at dose level 2, 2 out of 3 patients had dose-limiting toxicity and 3 additional patients treated at dose level 2 confirmed that the maximum tolerated dose had been reached. CONCLUSIONS: The recommended gemcitabine dose in combination with docetaxel (35 mg/m2 for a phase II study) was established at 900 mg/m2.
