The integration of paclitaxel and new platinum compounds in the treatment of advanced ovarian cancer

Abstract

There has been a steady improvement in the survival of patients with advanced ovarian cancer. This has been the result of a more skilled surgical approach to these patients and the development of more effective chemotherapy with a better integration of both modalities in first-line treatment. The current optimal chemotherapeutic approach consists of a platinum compound together with paclitaxel. This recommendation is based upon level I evidence of two large randomized trials which established that the combination of paclitaxel-cisplatin was superior to cyclophosphamide-cisplatin. The long-term follow-up of one of these studies continues to show a significant difference in survival at 5 years. Neurotoxicity has been problematic with these regimens, in particular when paclitaxel was given with the higher dosed shorter infusion schedule, as was done in the European-Canadian Intergroup study. Several approaches to reduce this toxicity have been studied. Among these are the use of different paclitaxel infusion schedules, and the application of less neurotoxic platinum compounds. Weekly paclitaxel has a different toxicity profile than the higher dosed three-weekly schedules, with less neutropenia, alopecia, arthralgia and neurotoxicity. Four platinum compounds are currently marketed: cisplatin, carboplatin, oxaliplatin, and nedaplatin. Of these only cisplatin, carboplatin, and nedaplatin have been approved for the treatment of patients with ovarian cancer (nedaplatin only in Japan). The equivalence of carboplatin and cisplatin has been suggested from trials without a taxoid. Three randomized studies of paclitaxel-carboplatin vs. paclitaxel-cisplatin concluded that paclitaxel-carboplatin is the preferred regimen in terms of (less) toxicity and, where studied, in terms of quality of life. So far, no difference in response rates or progression-free survival has been shown. More mature data on overall survival are awaited. Oxaliplatin (a diaminocyclohexane platinum compound) is of interest because it is only partially cross-resistant with cis- or carboplatin and devoid of severe bone marrow suppression, nephrotoxicity, or ototoxicity. Its dose-limiting toxicity is an unusual form of sensory neuropathy, which is cumulative and, contrary to cisplatin's neurotoxicity, generally reversible. Combinations with other active standard agents, as well as platinum compounds and/or taxoids, are feasible and have shown interesting activity. Similar to carboplatin and oxaliplatin, nedaplatin (cis-diammineglycolatoplatinum) can be given without hydration; its dose-limiting toxicity is myelosuppression, in particular thrombocytopenia. Although activity has been shown, no data from randomized comparative trials are available to allow a judgement on its potential advantages.