Summary performance of the Random Forest models predicting Oncotype DX risk groups.

Recurrence Scores were predicted using the clinico-pathological variables listed in S2 Table alone (pRS), or using the S2 Table variables in addition to gene expression scores for ER, PgR and HER2 that were included in the official Oncotype DX reports (pRSodx). Evaluation of performance of the Random Forest models was based on the extent to which the models correctly predicted, or failed to predict, each patient’s actual low- or high-risk Oncotype DX category. Values represent the mean outcomes ± standard deviations over 1,000 testing iterations.