Improving communication of breast cancer recurrence risk

Doctors commonly use genomic testing for breast cancer recurrence risk. We sought to assess whether the standard genomic report provided to doctors is a good approach for communicating results to patients. During 2009-2010, we interviewed 133 patients with stages I or II, node-negative, hormone receptor-positive breast cancer and eligible for the Oncotype DX genomic test. In a randomized experiment, patients viewed six vignettes that presented hypothetical recurrence risk test results. Each vignette described a low, intermediate, or high chance of breast cancer recurrence in 10 years. Vignettes used one of five risk formats of increasing complexity that we derived from the standard report that accompanies the commercial assay or a sixth format that used an icon array. Among women who received the genomic recurrence risk test, 63% said their doctors showed them the standard report. The standard report format yielded among the most errors in identification of whether a result was low, intermediate, or high risk (i.e., the gist of the results), whereas a newly developed risk continuum format yielded the fewest errors (17% vs. 5%; OR 0.23; 95% CI 0.10-0.52). For high recurrence risk results presented in the standard format, women made errors 35% of the time. Women rated the standard report as one of the least understandable and least-liked formats, but they rated the risk continuum format as among the most understandable and most liked. Results differed little by health literacy, numeracy, prior receipt of genomic test results during clinical care, and actual genomic test results. The standard genomic recurrence risk report was more difficult for women to understand and interpret than the other formats. A less complex report, potentially including the risk continuum format, would be more effective in communicating test results to patients.