BACKGROUND: Genomic recurrence risk test results now inform clinical decisions 
about adjuvant treatment for women with early-stage breast cancer. We sought to 
understand patients' knowledge of these tests and correlates of their knowledge.
METHODS: Participants in this cross-sectional study were 78 women, treated for 
early-stage, estrogen receptor-positive breast cancer with 0-3 positive lymph 
nodes, whose medical records indicated they received Oncotype DX testing 
earlier. We mailed a questionnaire that assessed knowledge of genomic recurrence 
risk testing (13 item scale, alpha=0.83) and reviewed medical charts of 
consenting patients.
RESULTS: Knowledge about genomic recurrence risk testing was low (mean knowledge 
score=67%, SD=0.23). Low knowledge scores were more commonly due to responses of 
'don't know' than incorrect answers. Most women (91%) clearly understood that 
test results can aid decisions about chemotherapy, and few (22%) understood that 
the test's estimate of the chance of metastasis assumes the patient is receiving 
hormone therapy. Higher knowledge about genomic recurrence risk testing was 
associated with higher education, reading ability, and numeracy. Knowledge was 
higher among women who recalled receiving both verbal and printed information 
about the test and among women who had active roles in deciding about their 
treatments. Higher knowledge was also associated with having fewer concerns 
about genomic testing.
DISCUSSION: Among early-stage breast cancer patients who received Oncotype DX, 
we found low knowledge about many aspects of genomic recurrence risk testing. 
Research is needed to understand testing information provided to patients and 
best practices for patient education.