Integrating a next generation sequencing panel into clinical practice in ovarian cancer

Purpose: Few efforts have been made to integrate a next generation sequencing (NGS) panel into standard clinical treatment of ovarian cancer. The aim of this study was to investigate the clinical utility of NGS and to identify clinically impactful information beyond targetable alterations. Materials and Methods: We conducted a retrospective review of 84 patients with ovarian cancer who underwent NGS between March 1, 2017, and July 31, 2018, at the Yonsei Cancer Hospital. We extracted DNA from formalin-fixed, paraffin-embedded tissue samples of ovarian cancer. The TruSight Tumor 170 gene panel was used to prepare libraries, and the MiSeq instrument was used for NGS. Results: Of the 84 patients, 55 (65.1%) had high-grade serous carcinomas. Seventy-three (86.7%) patients underwent NGS at the time of diagnosis, and 11 (13.3%) underwent NGS upon relapse. The most common genetic alterations were in TP53 (64%), PIK3CA (15%), and BRCA1/2 (13%), arising as single nucleotide variants and indels. MYC amplification (27%) was the most common copy number variation and fusion. Fifty-seven (67.9%) patients had more than one actionable alteration other than TP53. Seven (8.3%) cases received matched-target therapy based on the following sequencing results: BRCA1 or 2 mutation, poly ADP ribose polymerase inhibitor (n=5); PIK3CA mutation, AKT inhibitor (n=1); and MLH1 mutation, PD-1 inhibitor (n=1). Fifty-three (63.0%) patients had a possibility of treatment change, and 8 (9.5%) patients received genetic counseling. Conclusion: Implementation of NGS may help in identifying patients who might benefit from targeted treatment therapies and genetic counseling.