Background: The number of veterans diagnosed and treated for breast cancer within the VHA is increasing. The VA Central Cancer Registry (VACCR) reported 504 and 624 newly diagnosed patients in 2011 and 2012, respectively. Molecular testing for cancer treatment is also increasing, but there are few studies evaluating utilization and health outcomes of testing. This study examined utilization of OncotypeDx breast (Genomic Health Inc., Redwood City, CA), a prognostic 21-gene expression genomic test within the VA.
Methods: Patient-level test orders and results from January 2011 until December 2014 were provided by Genomic Health. Data for years 2011 and 2012 were merged with the VACCR. We identified OncotypeDx-eligible patients using reported clinical and pathologic stage of I or II, hor-mone receptor/HER2 (HR/HER) status, and 10-year life expectancy (aged < 75 years). Bivariate analyses were conducted to compare distributions of characteristics by status of testing. A multivariate logistic regression model was developed to identify patient, site of care, and regional factors that predict testing.
Results: There were 585 OncotypeDx breast assays ordered by VA and non-VA providers from 2011 until 2014. Testing increased from 65 tests in 2011 to 199 in 2014. Characteristics of patients tested were 97% female; median age 58 years (range 26-85 years ; 24% aged < 50 years). Of the 204 tests that were performed by Genomic Health during 2011/2012 time frame, 104 veterans were matched to VACCR data. Of 418 eligible veterans, 21.05% (88) were tested. There were 16 veterans who underwent testing but were not eligible due to age, stage, or HR/HER status. There were no statistically significant differences in use of testing by age or race. Recurrence score for veterans tested ranged from 0-50 (median = 17.40, SD 10.91); 58 (55.77%) low, 35 (33.65%) moderate, and 11 (10.58%) high risk of recurrence. Chemotherapy was used by 26 (25%) veterans who underwent testing and by 395 (38.16%) veterans not tested (P < .025).
Conclusions: There has been a rapid increase in use of the 21-gene risk score test among patients with breast cancer within the VA. Ongoing research will examine regional/site of care variations in access, and we will analyze the influence of testing on health outcomes.