Utilization of next-generation sequencing and associated systemic therapy initiation in metastatic prostate cancer.

Abstract

e19308 Background: There is emerging evidence for using clinical genomic classifiers for prognostication and to guide treatment choice in metastatic prostate cancer (mPC). While clinical-grade next generation sequencing (NGS) tests are increasingly available, how NGS has impacted systemic therapy selection for mPC is unclear. Methods: We performed retrospective observational study using the nationwide US Flatiron Health EHR-derived de-identified database. We identified patients with mPC diagnosed between January 1, 2013 and September 31, 2019. Receipt of NGS testing was chart-confirmed. “Short-interval” systemic therapy initiation in association with NGS testing was defined as line of therapy start within 30 days of documented NGS test result date. Results: A total 11548 mPC patients were included in our cohort, of which 1034 patients (8.9%) had documented NGS after metastatic diagnosis. There were 1210 documented NGS tests total, with 146 (14.1%) patients documented as undergoing NGS testing on more than one occasion. Median time from metastatic diagnosis to initial NGS test results was 560 days (IQR 194 to 1016 days). NGS test documentation increased from 7.1% of cases diagnosed in 2013 to 12.1% of cases diagnosed in 2017 (p < 0.001). A new line of systemic therapy was initiated within 30 days for 207 NGS test results (17.1%). Although the percent of NGS tests associated with short-interval initiation of a new line of therapy increased from 11.1% in 2013-2014 to 16.5% in 2018-2019, the difference was not statistically significant (p = 0.540). The most common systemic therapies initiated within 30 days after NGS testing were docetaxel (18.8%), cabazitaxel (16.8%), and abiraterone (15.4%). Conclusions: While there has been an increase in documented NGS tests in mPC, rates of short-interval systemic therapy initiation after NGS did not change significantly from 2013-2019. Further study is needed as to whether this will increase in years to come, as well as potential improvements in clinical outcomes due to therapy change.