Gene patterns reported to predict overall survival of breast cancer patients have been shown not to lose their predictivity upon normalization of the gene expression for cell division rate. In this work, we tested the hypothesis that recurrence prediction using machine learning also captures cell division rate rather than specific properties of the tumors that are more likely to recur. Comparing the ability of the XGBoost classification algorithm, we found that recurrence prediction accuracy is not affected by normalization for cell division rate. These results allow us to reject this hypothesis. By rejecting this hypothesis we support the hypothesis that cancer recurrence prediction captures signals that are not directly related to tumors’ cell proliferation rate.