Precision Oncology of High-Grade Ovarian Cancer Defined through Targeted Sequencing.

ABSTRACT

BACKGROUND: We examined whether molecular characterization of high-grade epithelial ovarian cancer can inform the diagnosis and/or identify potential actionable targets. METHODS: All of the consecutively sequenced high-grade ovarian tumours with consent between 2014 until 2019 were included. A total of 274 tumours underwent next generation sequencing using a targeted panel. RESULTS: Patients with high-grade ovarian epithelial cancer were consented to prospective molecular characterization. Clinical information was extracted from their medical record. Tumour DNA was subjected to sequencing, and selected patients received PARP inhibitor therapy. CONCLUSIONS: Tumours from 274 women were sequenced, including high-grade serous carcinoma (n = 252), clear cell carcinoma (n = 4), carcinosarcoma (n = 9), endometrioid carcinoma (n = 3), undifferentiated carcinoma (n = 1), and mixed tumours (n = 5). Genomic profiling did not influence histologic diagnosis. Mutations were identified in TP53, BRCA1, BRCA2, as well as additional homologous recombination repair pathway genes BARD1, ATR, CHEK2, PALB2, RAD51D, RAD50, SLX4, FANCA, RAD51C, and RAD54L. In addition, mutations in PTEN and CDKN2A were identified. Several somatic mutations with implications for germline testing were identified, including RMI1, STK11, and CDH1. Germline testing identified 16 previously unknown BRCA1/2 carriers. Finally, 20 patients were treated with the PARP inhibitor olaparib based on the sequencing results.