Objectives: To evaluate the role of an in vitro drug resistance assay to predict the response to platinum and taxane combination chemotherapy in advanced ovarian and uterine carcinosarcoma.
Methods: We evaluated all patients with FIGO stage II-IV ovarian and FIGO stage III-IV uterine carcinosarcoma, who received platinum and taxane chemotherapy after initial cytoreductive surgery between January 1, 1995 and March 31, 2008. Cases that received neoadjuvant chemotherapy were excluded. Patient demographics, clinicopathologic data, response to chemotherapy, and follow-up outcomes were abstracted from the medical records. In vitro drug resistance assay results (Extreme Drug Resistance [EDR] Assay, Oncotech Inc, Tustin, CA) were evaluated. Response to chemotherapy was then compared with the assay results.
Results: There were 51 cases in which in vitro drug resistance assay results were available, of which 17 (33.3%) received combination chemotherapy with platinum and taxane. For these 17 cases, the primary site of disease was ovary in 12 cases and uterus in the other 5 cases. Overall response rate for these 17 cases was 70.6%. Chemotherapy response in the presence of EDR to at least 1 of the 2 drugs (EDR-PT) was significantly lower than non-EDR-PT (37.5% vs. 100%, P = 0.009). Sensitivity, specificity, positive predictive value, and negative predictive value for chemotherapy response in non-EDR-PT were 75%, 100%, 100%, and 62.5%, respectively. EDR-PT showed a significantly lower progression-free survival (1-year progression-free survival rate, 28.6% vs. 100%, P = 0.01) and overall survival (5-year overall survival rate, 26.9% vs. 57.1%, P = 0.033).
Conclusions: Use of an in vitro drug resistance assay was a feasible test to predict the chemotherapy response and survival outcome in advanced ovarian and uterine carcinosarcoma.