Introduction

Active Surveillance (AS), a recommended management approach for low risk PCa, has been widely implemented within VA Medical Centers (VAMCs). However, Veteran characteristics such as age, race, and Agent Orange (AO) exposure may limit use of AS in some patients. The GPS test uses tumor biology to predict likelihood of favorable pathology. GPS may improve risk stratification for patients who are perceived as higher risk. To date, no published studies describe treatment patterns for Veterans following use of genomic tests. This study compares treatment patterns before and after introduction of the GPS assay within 6 VAMCs.

Methods

Men with newly diagnosed, NCCN very low, low, or intermediate risk PCa were eligible. We established treatment patterns in an untested patient cohort by reviewing charts from 2013-2014. From 2015-2016, we introduced the GPS assay within these same VAMCs in a prospective study. Six months after biopsy results, we reviewed charts to establish treatments patterns for both untested and tested Veterans.

Results

There were 200 men in the untested cohort and 190 men in the tested cohort. Patient characteristics were similar across groups. AS increased by 12% overall. The largest increase was among patients under age 60 (33% increase). AS increased in all NCCN risk groups with the largest increases in NCCN low risk (16%) and across racial subgroups (11% Caucasian, 16% Black, 20% Other). Veterans exposed to AO showed a small decrease in AS, while Veterans without exposure showed a 19% increase in AS. Median GPS was similar across racial groups and between Veterans exposed and not exposed to AO._x000D_ _x000D_

Conclusions

In clinically similar cohorts of untested and tested Veterans, implementation of the GPS assay increased use of AS across all age, risk, and racial groups. The assay showed similar biological risk between Caucasians and Blacks and Veterans exposed and not exposed to AO. GPS may be a useful tool to refine risk assessment of PCa and to increase the already high rates of AS among clinically and biologically low risk patients, regardless of their race and AO exposure. Future studies of Black and AO exposed Veterans, including persistence on AS, are needed confirm these findings._x000D_

Funding

Genomic Health Inc.