The understanding of the molecular mechanisms that underlie all stages of tumor progression in breast cancer (BC) represents an important goal in the biomedical research of this disease, particularly for the identification of more specific targeted therapies. In this context, BC preinvasive and precursor lesions represent a major dilemma. These lesions are well characterized under the phenotypic and genotypic profile, but it is not clear if they represent obligatory passages of a multistep process determining breast cancer evolution. In fact, the numerous cytogenetic and molecular alterations identified are not always representative of the progression into invasive phenotypes.
Keywords: breast cancer precursor lesions; molecular alterations; tumor progression.