Circulating tumor DNA analysis using targeted sequencing of 508 clinically actionable genes in patients with high grade serous ovarian cancer.

5582Background: The prediction of tumor chemoresponse and treatment toxicity is crucial for optimal patient care in high grade serous ovarian cancer (HGSC). We employed a targeted sequencing panel of 508 clinically annotated cancer genes to screen for actionable genetic variants in tumor tissue and ctDNA of patients with advanced HGSC. Methods: Tumor tissue, and serial plasma samples at diagnosis and during primary therapy were obtained from five patients with FIGO Stage IIIc HGSC. All patients were surgically debulked and received standard carboplatin and paclitaxel chemotherapy. DNA isolated from tumor tissue and plasma was analyzed for genetic alterations by targeted deep-sequencing of 508 previously annotated cancer genes. Somatic variants were systematically reported for alterations related to drug sensitivity and treatment toxicity, and analyzed with respect to clinical parameters and primary therapy outcomes. Results: In tumor tissues, and the corresponding pre-treatment ctDNA, oncogenic mutations ...