[Therapy of anthracycline-resistant metastatic breast carcinoma]

Abstract

Treatment of anthracycline-resistant metastatic breast cancer with new antineoplastic agents remains a challenge for the next future. The 5-year survival for this disease is only 15%, and hormonal and chemotherapeutic options remain essentially palliative. New treatment drugs or drug combinations are urgently needed to improve the prospects for patients with metastatic breast cancer, particularly for those with disease characteristics indicating a particularly poor prognosis. Taxanes are promising new drugs and have shown encouraging activity in patients with disease resistant to anthracyclines and in patients with visceral metastases, both with a poor prognosis. Paclitaxel (taxol) is applied with a dose of 175 mg/m2 in a 3 hour infusion and docetaxel (taxotere) with a dose of 100 mg/m2 q 3 weeks. Remission rates are expected between 6-30% for taxol and between 29-48% for docetaxel. Highly active in patients with anthracycline-resistant disease appears to be the vinca-alkaloid vinorelbine too. In patients treated with adriamycin objective remissions between 15-33% can be obtained. The long time known 5-fluorouracil comes to the third place of the effective drugs. Continuous infusion or addition of folic acid increases the intracellular efficacy and results in 5-53% objective remissions. In second-line chemotherapy platin-analogues together with etoposide, vincristine and 5-FU achieve partial or complete remissions between 19-37% for cisplatin containing and 5-12 for carboplatin containing combinations. This may eventually play a role especially if three drug combinations containing paclitaxel, epirubicin and vinorelbine will be used, which are reported to result in 20-33% complete response rates and 66% objective response. The indication for other new drugs like tomudex, topoisomerase-I-inhibitor and gemcitabine for anthracycline-resistant breast cancer remains to be established in multicenter studies.