In vitro chemoresponse in metachronous pairs of ovarian cancers.

BACKGROUND/AIM: An in vitro chemoresponse assay may aid effective therapy selection in epithelial ovarian cancer (EOC). This study explores changes in chemoresponse between paired primary and recurrent EOC tumors. PATIENTS AND METHODS: RESULTS from metachronous tumors were examined in 242 patients. Changes in in vitro chemoresponse, measured by the area under the dose response curve (AUC) between paired tumors were assessed. RESULTS: A significant increase in AUC was identified in most first-line therapies over time. No significant difference was observed in most recurrent therapies. When the elapsed time between occurrences was <17 months, no difference was observed for any recurrent therapies, and half of first-line therapies exhibited significant increases in AUC. When ≥17 months, all 7 therapies showed significant increases. CONCLUSION: These results suggest an increase in chemoresistance over time, which is more pronounced for first-line therapies. This is consistent with clinical observations and suggests the biologic concordance between assay results and response to chemotherapy.