Efficacy of taxane and platinum-based chemotherapy guided by extreme drug resistance assay in patients with epithelial ovarian cancer

Objective: To evaluate the efficacy of taxane and platinum-based chemotherapy guided by extreme drug resistance assay (EDRA) in patients with epithelial ovarian cancer. Methods: Thirty-nine patients were enrolled, who were diagnosed as epithelial ovarian cancer, tubal cancer or primary peritoneal carcinoma and received both debulking surgery and EDRA in Asan Medical Center between August 2004 and August 2006. Another thirty-nine patients were enrolled, who did not receive EDRA as control. Paclitaxel 175 mg/m(2) and carboplatin AUC 5 were administered as primary combination chemotherapy to both EDRA group and the control group. In the EDRA group, paclitaxel was replaced by docetaxel 75 mg/m(2) if a patient showed extreme drug resistance (EDR) to paclitaxel and not to docetaxel. Carboplatin was replaced by cisplatin 75 mg/m if a patient showed EDR to carboplatin and not to cisplatin. If only one drug showed low drug resistance (LDR), it was allowed to add another drug which showed LDR such as gemcitabine 1,000 mg/m(2). CT scan was performed every three cycles and CA-125 was checked at each cycle. Results: There was no significant difference in overall response rate between EDRA group and the control group (84.5% vs. 71.8%, p=0.107). However, 93.8% of patients in EDRA group did not show EDR to at least one drug and its response rate was significantly higher than that of the control group (93.3% vs. 71.8%, p=0.023). Conclusion: we could choose a combination of taxane and platinum which did not show EDR and could obtain a good response in the patients with ovarian cancer.