In vitro extreme drug resistance assay to taxanes or platinum compounds for the prediction of clinical outcomes in epithelial ovarian cancer: a prospective cohort study.

PURPOSE

We sought to investigate the efficacy of in vitro extreme drug resistance (EDR) assay for the prediction of drug response, platinum-resistance (progression-free survival, PFS <6 months) and survival in patients with epithelial ovarian cancer (EOC) who received taxane- and platinum-based chemotherapy after surgery.

METHODS

Between December 2005 and August 2007, 43 patients were enrolled prospectively. They underwent staging laparotomy followed by six or nine cycles of taxane- and platinum-based chemotherapy, and their tumors were submitted for in vitro EDR assay to taxanes (paclitaxel or docetaxel) and platinum compounds (carboplatin or cisplatin).

RESULTS

The rates of EDR to taxanes and platinum compounds were 20.9% (9/43) and 23.3% (10/43). Patients with EDR to platinum compounds showed a lower rate of overall response (60 vs. 100%), a higher rate of platinum-resistance (50 vs. 18.2%) and poor overall survival (OS) (median OS; 29.2 vs. 33.7 months) than those without EDR to platinum compounds (P < 0.05), whereas patients with EDR to taxanes showed poor PFS than those without EDR to taxanes (12.5 vs. 19 months, P < 0.01). Moreover, suboptimal debulking surgery and EDR to taxanes were poor prognostic factors for PFS (adjusted hazard ratio 3.215 and 3.984; 95% confidence interval 1.845-7.895 and 3.814-11.674, respectively) although there was no independent risk factor for poor OS by the multivariate Cox's proportional hazard analysis.

CONCLUSIONS

In vitro EDR assay to taxanes and platinum compounds may be helpful for predicting drug response, platinum-resistance and survival in patients with EOC who received taxane- and platinum-based chemotherapy after staging laparotomy.