TAXANES IN ADJUVANT AND NEOADJUVANT THERAPIES FOR BREAST-CANCER

Paclitaxel (Taxol) is a diterpene originally obtained from the bark of the Pacific Yew Tree, Taxus Brevifolia. Ifs mechanism of action is un ique, rf stabilizes microtubule polymerization, thus blocking cells in the G(2)/M phase of the cell cycle, In breast cancer, initial studies using paclitaxel demonstrated high activity. The first study was repo rted in 1991 by Holmes et al who gave paclitaxel as a 24-hour infusion at 250 mg/m(2) to 25 patients with metastatic breast cancer following only one prior chemotherapy regimen-they achieved a 56% response rate , Since then, numerous studies have confirmed the effectiveness of pac litaxel in patients whit metastatic disease, A second taxane, docetaxe l (Taxotere), has also demonstrated excellent activity. Clinical resea rch is now focused on integrating the taxanes into combination drug re gimens and into neoadjuvant and adjuvant schedules for patients with e arly stage breast cancer, as well as leaking at the biologic determina nts of response and resistance to taxanes. This article will review de velopments in the use of taxanes in the adjuvant and neoadjuvant setti ngs and it will review the information on possible molecular markers t hat may be useful in predicting tumor responsiveness to taxanes.