Treatment with Paclitaxel Alone Rather than Combination with Paclitaxel and Cisplatin May be Selective for Cisplatin-resistant Ovarian Carcinoma

BACKGROUND: We have previously reported that paclitaxel (taxol) results in cisplatin sensitization to human ovarian cancer cells with cisplatin resistance in vitro. This study was designed to determine effects of taxol and its combination with cisplatin on growth of cisplatin-sensitive cell line (KF28) and the cisplatin-resistant counterpart (KFr13) in nude mice. METHODS: From 14 days after tumor inoculation treatment was initiated. Taxol (3 mg/kg) and cisplatin (2 mg/kg) were administered i.p. once a week for 5 weeks. RESULTS: In nude mice bearing cisplatin-sensitive cells (KF28), taxol followed by cisplatin and cisplatin plus taxol inhibited significantly (P < 0.05) the tumor growth rate compared with that in nude mice treated with cisplatin alone or taxol alone and cisplatin followed by taxol. On the other hand, in nude mice bearing cisplatin-resistant KFr13 cells, treatment with taxol alone inhibited completely the tumor growth rate, whereas no schedule-dependent interaction of taxol with cisplatin was observed. CONCLUSION: These results suggest that treatment with taxol alone may be superior to combination of taxol with cisplatin in patients with cisplatin-resistant ovarian carcinoma.