The use of DNA promoter methylation testing for prostate cancer diagnosis in the Department of Veterans Affairs.

Abstract

394 Background: It is essential to study real-world evidence of novel molecular diagnostic tests to measure their impact on clinical decision-making and health outcomes. Studying test utilization within the Department of Veterans Affairs (VA) informs about clinical validity in a racially diverse population. This study analyzed the impact of DNA promoter methylation (ConfirmDx), on the diagnostic workup of Veterans. Methods: The VA Corporate Data Warehouse (CDW) was used to identify all incident prostate biopsies and cancers from 1/2014-10/2019. We captured patient clinical characteristics, including number and date of biopsies, date of cancer diagnosis, dates and values of PSA tests, comorbidities, demographics, whether the patient underwent DNA promoter methylation testing, and the results of that test. Results: Each year an average of 25,299 biopsies are conducted in the VA. Between 2014 and 2019, 151,794 biopsies were performed. 98,155 (70%) Veterans underwent first-time biopsies and 54,447 (55%) were positive for carcinoma. 8,062 (8.2%) underwent multiple biopsies, among whom 3,589 (44%) were subsequently diagnosed with cancer. 34 Veterans underwent 5 or more biopsies before being diagnosed. 33,878 (35%) did not undergo another biopsy in the study period. 328 (0.3%) of the 98,155 Veterans underwent the DNA promoter methylation test. 55 (17%) of these Veterans were eligible for Medicare coverage of the test. Of the 328 tested for DNA methylation, 217 (66%) were minorities. 132/328 (40%) tested positive for carcinoma and 168/328 (51%) were negative. Conclusions: Most Veterans referred for prostate biopsy have detectable cancer, and a large number are minorities with potential increased prostate cancer risk. DNA promoter methylation may improve care by reducing the need for multiple biopsies, limiting exposure to infection, and reducing time to diagnosis and treatment.