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 resist ance in vitro. This study was designed to determine effects of taxol and it s combination with cisplatin on growth of cisplatin-sensitive cell line (KF 28) and the cisplatin-resistant counterpart (KFr13) in nude mice. Methods: From 14 days after tumor inoculation treatment was initiated. Taxo l (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 follo wed by cisplatin and cisplatin plus taxol inhibited significantly (P < 0.05 ) the tumor growth rate compared with that in nude mice treated with cispla tin alone or taxol alone and cisplatin followed by taxol. On the other hand , in nude mice bearing cisplatin-resistant KFr13 cells, treatment with taxo l alone inhibited completely the tumor growth rate, whereas no schedule-dep endent interaction of taxol with cisplatin was observed. Conclusion: These results suggest that treatment with taxol alone may be su perior to combination of taxol with cisplatin in patients with cisplatin-re sistant ovarian carcinoma.