Abstract: A first exemplary method for performing a prognosis for a breast cancer patient, comprises the steps of determining the status of an aberration of the TOP2A gene in a tissue sample taken from the patient; and estimating the probability of either recurrence-free survival or of overall survival of the patient at a later time based upon a pre determined Hazard Ratio corresponding to the determined status. A second such exemplary method comprises the steps of determining the status of an aberration of the TOP2A gene in a tissue sample taken from the patient; and estimating the probability of either recurrence-free survival or of overall survival of the patient at a later time based upon a pre-determined Kaplan-Meier plot corresponding to the determined status.