Efficacy and toxicity of vinorelbine with doxorubicin/cyclophosphamide combination chemotherapy in a phase I-II study for advanced or recurrent breast cancer patients.

BACKGROUND

To evaluate the efficacy and toxicity of vinorelbine (VNB) with doxorubicin/cyclophosphamide (AC) combination chemotherapy, a phase I-II study was carried out in patients with advanced or recurrent breast cancer.

METHODS

The phase I part of this study was carried out to determine the treatment schedule and acceptable dose of VNB for the phase II study. In phase I, VNB was initially given as a short infusion on days 1, 8 and 15, every 4 weeks. The initial dose of vinorelbine was 15 mg/m2. In the AC regimen, 20 mg/m2 of doxorubicin (ADM) was given intravenously (i.v.) on days 1 and 8, and 100 mg/body of cyclophosphamide (CPA) was administered orally from days 1 to 14. Subsequently, a phase II study was carried out at the maximum acceptable dose (MAD).

RESULTS

Twenty-three patients were entered into this study. In patients receiving VNB at a dose of 15 mg/m2, neutropenia (> or = grade 3) frequently occurred on day 15. The treatment schedule of this study was therefore changed to VNB given i.v. on days 1 and 8 with AC combination chemotherapy. In this treatment schedule, grade 4 neutropenia lasting for more than 4 days occurred in patients given VNB at a dose of 20 mg/m2 with AC more frequently than in those given 15 mg/m2 of VNB. Therefore, the MAD of VNB was determined to be 20 mg/m2 in this regimen. At this recommended dose, there were 1 complete (CR) and 8 partial responses (PRs) in 15 patients, with an overall response rate of 60.0%. No treatment-related death occurred.

CONCLUSIONS

These data indicate that VNB plus AC combination chemotherapy was effective and well tolerated for breast cancer patients. A randomized trial of VNB plus AC vs. AC combination chemotherapy may be required to ascertain the benefit of this regimen for advanced or recurrent breast cancer patients.