The Utility of Next-Generation Sequencing in Advanced Breast and Gynecologic Cancers Experience of a Large Tertiary Care Women's Hospital

Objectives: Next-generation sequencing (NGS) has the potential to identify genetic alterations that are actionable with targeted therapy. Our objective was to identify the impact of NGS testing on advanced breast and gynecologic malignancies. Methods: A retrospective review of 108 patients who underwent NGS testing between 2015 and 2019 was performed. The NGS clinical action rate was calculated based on documentation of positive clinical action taken in cases with an actionable NGS result. Results: The 108 specimens tested included 35 breast cancers and 73 gynecologic malignancies, with most of the testing performed at Foundation Medicine (90%). Actionable mutation(s) were identified in 79 (73%) of 108 cases. The overall clinical action rate of NGS testing was 38% (30 of 79 cases). Overall, 47 (44%) of 108 patients died, all succumbing to disease. The average survival was 10.9 months. The survival difference between patients with actionable NGS result and targeted treatment, actionable NGS result but no targeted treatment, and patients with nonactionable NGS result was not significant (log-rank test, P =.5160). Conclusions: NGS testing for advanced breast and gynecologic cancers at our institution has a 38% clinical action rate. However, the increased clinical action rate over the years did not translate into improved survival.