Performance, model size distribution and variable stability of reduced models as described in Figure 1 for node-negative (node(-)) and hormone receptor positive (+) subpopulation. We included patients whose tumors were estrogen receptor (ER) positive, progesterone receptor (PR) positive or both. The left column shows the models for all variables excluding nodal status, and the right column shows models for the clinico-pathological variables alone (tumor size, nuclear grade, age, human epidermal growth factor receptor (HER) 2, ER, PR). The compact, reduced model (RM) derived from molecular and clinico-pathological covariates dramatically outperformed the full models (FM), and included AURKA, tumor size, HER2, CD68 and nuclear grade. ATD-AUCROC, average time-dependent area under the receiver operator characteristic curve.