Recent advances in the prevention of anthracycline cardiotoxicity in childhood.

The prevention of anthracycline cardiotoxicity is particularly important in children who can be expected to survive for decades after cancer chemotherapy with these agents. The rapid increase in clinical toxicity at doses greater than 550 mg/m(2) of doxorubicin (DOX) has made this dose the limiting one in order to avoid DOX-induced cardiac failure. However, arbitrary dose limitation is inadequate because of variability of individual tolerance. Decreasing myocardial concentrations of anthracyclines (ANT) and their metabolites and schedule modification of administration can reduce anthracycline cardiotoxicity. Anthracycline structural analogues such as epirubicin, idarubicin and mitoxantrone have been used in clinical practice. In addition, the liposomal ANT, which can be incorporated into a variety of liposomal preparations, are a new class of agents that may permit more specific organ targeting of ANT, thereby producing less cardiac toxicity. Much interest has focused on the administration of ANT in conjunction with another agent that will selectively attenuate the cardiotoxicity. As is known, the ANT chelate iron and the DOX-iron complex catalyzes the formation of extremely reactive hydroxyl radicals. Many agents, such as dexrazoxane (DEX), able to remove iron from DOX, have been investigated as anthracycline cardioprotectors. Clinical trials of DEX have been conducted in children and significant short-term cardioprotection with no evidence of interference with antitumor activity has been demonstrated. Whether long-term cardiac toxicity will also be avoided in surviving patients has not yet been determined.

[Breast cancer: new therapeutic strategies]. / Cancer du sein: nouveautés thérapeutiques.

NEED FOR NEW CHEMOTHERAPY AGENTS: Metastasic breast cancer is an excellent model for studying anticancer agents: chemotherapy or hormonotherapy or compounds modifying the organism's response. If no adjuvant treatment is given after locoregional treatment of breast cancer, metastasis will develop within 10 years in 30% of the patients free of initial nodal invasion and within 5 years in 50% of the patients with initial nodal invasion. ADJUVANT TREATMENTS: Hormonotherapy and chemotherapy reduce mortality due to breast cancer by 10%. New adjuvant agents have been recently introduced. Taxans (docetaxel, paclitaxel) are the most active molecules since antracyclines. New aromataase inhibitors include letrozole and anastrozole. Their efficacy has been demonstrated in phase II and phase III trials, allowing their experimentation as adjuvant treatments.