Chemotherapy time interval and development of platinum and taxane resistance in ovarian, fallopian, and peritoneal carcinomas

OBJECTIVE: To evaluate drug resistance after exposure to neoadjuvant chemotherapy and to postoperative chemotherapy in epithelial ovarian, fallopian, and primary peritoneal carcinomas.
METHODS: In vitro drug resistance assay results (EDR Assay, Oncotech, Inc.) for platinum and taxane were evaluated for the following three groups: (1) primary cytoreductive surgery without prior chemotherapy; (2) primary cytoreductive surgery after neoadjuvant chemotherapy with platinum and taxane; and (3) recurrent cases after postoperative chemotherapy with platinum and taxane. Proportions of extreme drug resistance (EDR) were analyzed with Fisher's exact test.
CONCLUSIONS: Platinum resistance was common after neoadjuvant chemotherapy, while paclitaxel resistance was common after postoperative chemotherapy.