Prognostic and predictive factors.

Prognostic factors are key elements for medical oncologists to select, among the group of patients with early breast cancer, those who are candidates for an adjuvant treatment based on their risk of tumor relapse. Predictive factors drive the decision of which type(s) of treatment should be given. If we perform a literature search on prognostic and predictive factors in breast cancer we immediately realize how redundant is the number of markers that have been/are being evaluated and a dedicated book would be needed to review all of them critically. So, for the purpose of writing this chapter, I have decided to start from markers whose roles have been established to be relevant for patient care by an international panel of breast cancer experts [1].