iCTC drug resistance (CDR) Testing ex vivo for evaluation of available therapies to treat patients with epithelial ovarian cancer.

GOALS

Management of epithelial ovarian cancer (EOC) could use serial measurements of invasive circulating tumor cells (iCTCs) for monitoring therapeutic response and early detection of disease progression/recurrence. Goals of this study are to develop an iCTC drug resistance (CDR) assay and to evaluate clinical significance of patient-derived, cultured iCTCs in selecting available therapies.

METHODS

The CDR assay using Taxol-Carboplatin and eight other EOC drugs at the concentration used for patients was performed. Blood was donated by six patients before primary Taxol-Carboplatin chemotherapy, one recurrent patient, six patients during and after their course of chemotherapy, and two patients with benign disease for procedure control. CDR score above and below 100 indicates sensitivity and resistance, respectively, to that drug.

RESULTS

Five of six pre-therapy samples had >20 iCTCs/>111 CDR for Taxol-Carboplatin sensitivity, and one had 40 iCTCs/23 CDR for resistance. The recurrent sample had 58 iCTCs/5 CDR for resistance. Four of six post-therapy patients had iCTCs decreased to 0/>153 CDR indicating sensitivity, while two patients had >45 iCTCs/<85 CDR indicating resistance. The patients' treatment history and follow-up confirmed that patients were in response or remission when iCTCs were sensitive to Taxol-Carboplatin, and patients were in relapse or recurrence when iCTCs were resistant to Taxol-Carboplatin.

CONCLUSION

Further investigation on the CDR assay is warranted to examine its use in selecting drugs before treating a patient.