Overview of carboplatin: replacing, complementing, and extending the therapeutic horizons of cisplatin

Carboplatin is the one platinum analogue that has received widespread clinical testing both in cancers that are normally targets for cisplatin and in others. It was introduced in 1981 because of its lesser toxicity and equivalent biochemical selectivity and antitumor spectrum relative to cisplatin in preclinical systems. Clinical studies have generally confirmed these expectations and given rise to interesting prospects in current cancer therapeutics. Carboplatin is as effective as cisplatin in ovarian cancer and considerably less toxic. Replacement of cisplatin by carboplatin seems likely in a number of other diseases where cisplatin has played a major role, especially if ongoing phase III studies confirm the regimens are equivalent. Carboplatin may also complement cisplatin's role by its innovative integration into treatment strategies, and by use of it as additional treatment when cisplatin's nonhematologic toxicities are prohibitive. Finally, although it is not likely to possess a different therapeutic spectrum than cisplatin, carboplatin appears to be extending the indications for platinum compounds to new areas such as acute leukemia, endometrial cancer, and breast cancer. In the latter, use of autologous bone marrow reconstitution permits the dose intensity needed for promising therapeutic results. Carboplatin has become the experimental platinum analogue of choice in a wide range of new clinical situations and in combinations with other modalities.