[New drugs in metastatic breast cancer--1997].
The introduction of new drugs may offer significant hope for improvement in the treatment of breast cancer. They include new cytotoxic agents such as Taxanes, Topoisomerase inhibitor, MDR modulator, new hormone such as 3rd generation nonsteroidal aromatase inhibitor, pure antiestrogen for patients with refractory metastatic breast cancer and new bisphosphonates for those who have metastases to bone. Therefore, some reports evaluating such new drugs were reviewed. Japanese studies revealed response rate of Taxanes in the treatment of metastatic breast cancer as follows; Six out of 22 (27%) with 1 CR for 24 hours infusion, 21 out of 52 (34%) with 2 CR for 3 hours infusion of paclitaxel respectively, 21 out of 31 (41%) with 2 CR for 1 hour infusion, and 32 out of 72 (44%) with 5 CR for 1 hour infusion of Docetaxel, In addition, the MTD of the combination was reached at dose level with 60 mg/sqm of Docetaxel and 400 mg/sqm of cyclophosphamide. As regards hormone therapy, thirty four out of 176 (19%) with 5 CR were observed in phase II study of Fadrozol but results from the phase II study of 3rd generation aromatase inhibitor is not yet accomplished in Japan. However, any european reports did not show a difference in response rate in patients with tamoxifen refractory breast cancer between newer aromatase inhibitor and megasterol, and a good choice of hormones in the treatment of metastatic breast cancer appears to be difficult.