Increased paclitaxel resistance in recurrent epithelial ovarian cancer: analysis of metachronous tumors.

摘要

Whether or not ovarian cancer exhibits tumor heterogeneity before and after chemotherapy, demonstrated in an in vitro drug resistance assay, seems to remain controversial [1-4]. In the largest analysis of an unselected population with ovarian cancer, there was no significant difference in the proportion of extreme drug resistance (EDR) between primary and recurrent cases [1], On the other hand, a tax-ane-free interval longer than 1 year among 34 cases of epithelial ovarian cancer receiving platinum and taxane combination chemotherapy showed significant increased risk of EDR to taxane: paclitaxel 89.7%, and docetaxel 82.8% [2]. Their results were supported by other investigators, and marked increased EDR ratio was seen for paclitaxel [3], We previously demonstrated increased paclitaxel resistance after postoperative chemotherapy with platinum and taxane in epithelial ovarian, fallopian, and primary peritoneal cancers [4]. In our results, EDR to paclitaxel was more common in later recurrence, especially more than 5 years after the initial surgery [4].